AeroElectric-Archive.digest.vol-jm
April 21, 2010 - May 12, 2010
differences.
When the idea of measuring current required by the pump surfaced, that
seemed to have merit, but 'Lectric Bob seems to feel that may not be a useful
measurement. I think the pressure and electron measurement solutions are
worthy of some breadboard testing, but that optical monitoring of the fuel
looks like a winner. Unfortunately, I now have to figure out a way of getting
my local FED to agree that it is a good solution.
As an aside, It appears that an earlier offering by the Pillar Point
folks used a stock AN Tee for a base unit with the detector potted into the
standing leg of the tee. They have now decided to manufacture their own Tee.
It is my off the wall guess that I might have had better luck using the
modified AN unit than I will one that is newly manufactured. Such are the
vagaries of getting FAA approval for anything. I just hope that sometime in the
future I will be able to afford a homebuilt instead of my present factory
built steed.
This is WAY off topic, but my investigation of the market shows that I can
still buy an ancient factory built flying machine for less money than it
would cost to get a home built machine of equivalent performance.
This would be a no brainer if I could afford a homebuilt.
Difficulties such as I am now encountering may get me to change my mind!
Happy Skies,
Old Bob
In a message dated 4/21/2010 7:04:31 A.M. Central Daylight Time,
fran4sew(at)banyanol.com writes:
--> AeroElectric-List message posted by: "user9253"
A "tank empty switch" can be made with a magnet attached to a float inside
of the tank. A magnetic reed switch on the outside of the tank will close
when the magnet gets close to it. Of course this is only legal for
home-built aircraft. The only thing visible on the outside of the tank will be
a
pair of wires with heat-shrink on the end that the covers the switch.
Perhaps there are similar switches commercially available.
Joe
--------
Joe Gores
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=295073#295073
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <nuckolls.bob(at)aeroelectric.com> |
| Subject: | Re: Facet pumps: Energy vs. Flow |
At 08:08 AM 4/21/2010, you wrote:
>Good Morning Joe,
>
>Another great idea! This list is resourceful.
>
>For my purposes, the fuel gauge I have does a good job as far as
>telling me when my usable fuel is out of the tank. Admittedly,
>there are times when four or five minutes of fuel will make a
>difference and if the flight is planned to land with the FAA
>suggested thirty minute minimum planned fuel reserve, five more
>minutes will make a difference to me.
>
>However, I rarely cut fuel that close so my effort is oriented more
>toward reducing the time the pump will be operating dry. That is why
>I am more interested in finding out when the pump is pumping nothing
>but air. So far, the best answer appears to be the optical
>monitoring of fuel flow. I originally thought pressure would do the
>trick, but as many have pointed out, there may not be enough head
>pressure to allow consistent measurable differences.
>
>When the idea of measuring current required by the pump surfaced,
>that seemed to have merit, but 'Lectric Bob seems to feel that may
>not be a useful measurement.
I've researched the evolution of the thump-thump pumps
and found quite a cache of history in the patent files.
A selection of examples have been posted at:
http://aeroelectric.com/Mfgr_Data/Pumps/
It seems our old friend the "Bendix electric
pump" is well represented and appears to have been
taken over by Facet. An example of the Facet cube
pump is including. All of these are "solid state"
versions of the original design that simply used a
set of contacts to control the solenoid coil current
to re-stroke the pump. I was surprised to find
that "solid state" went back so far. The 1968
Bendix patent still has the mechanical switch
contacts but uses transistors to buffer the coil
current so that the contacts don't erode electrically.
Later versions use hall effect devices to sense
plunger position. The surprise was to find a
couple of designs that used a free-running
oscillator (555 timer) to simple pulse the
solenoid periodically. No plunger position
sensing at all.
It's possible that some versions will present
a unique current signature that could be used
to detect when the pump was running unloaded
but you'd have to do some all-conditions,
all-variables studies to make sure that your
sensing scheme did not risk false indications.
>I think the pressure and electron measurement solutions are worthy
>of some breadboard testing, but that optical monitoring of the fuel
>looks like a winner.
Back in the summer of 08 we had some discussion here
on the list about optical liquid level sensors. These
have a rich history of practical application in automotive
applications dating back to the 1950's.
Modern incarnations include a series of devices
I was responsible for at Electro-Mech in the 80's
that have been built by the thousands and incorporated
into dozens of applications on Beech/RAC/Hawker-Beech
products. Here's a collection of pictures that
show features and products in the optical liquid
level sensors technology:
http://aeroelectric.com/Pictures/Fuel_Level/
Gem Sensors is a good place to start for
commercial off-the-shelf devices. They're
quite rugged and entirely suited to the
task.
http://www.gemssensors.com/content.aspx?id=282
> Unfortunately, I now have to figure out a way of getting my local
> FED to agree that it is a good solution.
You're not proposing to do anything new,
daring and fraught with risk. Successful
integration of these devices into a tank
have only to do with mundane issues of
craftsmanship that go to keeping the fuel
inside the pipes . . . i.e. leaks.
The neat thing about sensing absolute
level in the tank is the "dipstick" accuracy
of the value. There are no variables of
calibration associated with setting trip
points to light indicators from fuel
level transmitters, etc.
I could see a 337 mod to add the sensor
to the side of a tank. It's an ADDITION
that is an operating convenience and
has no effect on the basis for certification
for the original TC. Risks are limited to
issues of good shop practice and craftsmanship.
Bob . . .
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <nuckolls.bob(at)aeroelectric.com> |
| Subject: | Re: RE: Designing a circuit question |
Hi Bob, and everyone else following this thread...
I have an even simpler solution, possibly costing significantly less,
using the hotly debated poly-fuse. Simply put a 6A or 7A one in
series with the motor, with an LED+resistor across it. When the fuse
trips, the LED is energised... In it's normal state, all the current
travels through the low impedance fuse, and 'none' through the
LED+resistor path. No heatsink required! However, there is the
problem of securing everything and making sure vibration doesn't age
the soldered joints prematurely.
I considered this. This is the control philosophy
for most cars on the electric window-risers. It's
certainly simple and reliable. They are relatively
slow acting devices and it would take some experimentation
to get the right device. Also, once they've tripped, it
may take 10 seconds or more for them to cool off enough
to reset. So once the light comes on, you would have
to wait for sufficient cooling to come off the stop.
But if that operating mode meets design goals,
it's certainly an option.
Does the current limiting characteristic you mention literally limit
the current to the pitch motor? My guess is it does (at least
somewhat), which is why the N-fet becomes a cabin heater.
But it's a heater only while you are in the current limited
mode. i.e. against the stop and the light is lit. Only a second
or so at a time (reaction time to release the switch after
the light comes on).
I'm thinking that the electrical paths from the switch to the N-fet,
and path from the N-fet to the ALSRJ resistor to ground need to be
capable of 10A, but the other wiring will see much less.
How would I 'adjust for desired limit' on the ALSRJ resistor to go up
to say 8A? How did you calculate or estimate that value? How
sensitive would you anticipate that to be?
The current limit calibration is a function of voltage
drop across the low value resistor and the base-emitter
turn-on voltage for the clamp transistor. Assuming 0.6
volts turn-on and 0.1 ohms, we get about 6 amps. I would
'trim' the set point to higher values by paralleling the
0.1 ohm resistor with another, higher value.
The reason I ask is that the load on the motor does increase as the
pitch on the blades approach the high (and low) pitch limits, before
the mechanical stop is reached. The mechanism is literally twisting
composite blades, they don't rotate in bearings like 'regular'
adjustable blades. I may have to adjust the current limit to be sure
I can get the blades close enough to the pitch limits for my
purposes. My rough measurement of current (reading a clamp on meter)
indicates a pretty good knee in the curve at around 8A. 6A may be
close enough, only testing will tell.
Exactly. Adding a 0.5 ohm resistor in parallel would
raise the set point to abut 7.2 amps. Adding another
.5 ohm raises it to 8.4 amsp, etc.
Finally, how would you compare this circuit to the reed switch
approach that Joe Gores proposed, from a standpoint of repeatability
of sensing the target amperage, and the ability to make adjustments
to get to the desired target (number of winds and wire size selection)?
The reed switch would only light the light, it would not
eliminate using the "breaker-trip" as the ultimate limit
switch. In the stone-simple category of solutions, the
polyswitch suggestion has some merit.
Related question. How is the amount of heat sink area calculated? I
assume it is based on the amount of energy converted to heat. Where can
I find the info to determine what size heat sink is required. Does the
electrically insulating material also thermally insulate the component
and affect the design of the heat sink?
Heat sinking is an interesting and not really complicated
discipline. It comes with two primary design goals to consider.
They might be characterized as the "marathon" and "100-yard dash"
modes for thermal management.
A heat sink's ability to keep a semiconductor cool is a
combination of thermal mass and surface area available
to reject heat. In the case of CONTINUOUS duty operation
like the linear dimmer modules, surface area and air
flow are the driving considerations. In our intermittent
duty application (1 second at each end of stroke), we
can use a heat sink that is horribly undersized for
continuous duty as long as total thermal mass is sufficient
to keep the transistor junction from fusing in the
few seconds per operation and sufficiently space to allow
cooling for the next cycle.
I didn't do a calculation for the suggestion that was
mostly an experience-based recommendation.
There's a lot of data available on the 'net that
speaks to continuous duty heat sink sizing and the
insulating, thermally conducting washers used to
electrically isolate the device from the heat sink.
Intermittent duty sizing is not so common although
it's easily estimated. It's a thermal rate-of-rise
study that accounts for junction to sink thermal
resistance + thermal inertia of the heatsink
where we consider the specific heat of the material
and it's total mass. I think I've got some words
that discuss that process somewhere, I'll dig around.
In any case, for this application, we don't need
to design a heat-sink that allows the transistor
to operate in an extended "cabin heater" mode.
Bob . . .
________________________________________________________________________________
| From: | BobsV35B(at)aol.com |
| Subject: | Re: Facet pumps: Energy vs. Flow |
Good Morning 'Lectric Bob,
Thanks for the update.
Your answer coordinates well with my thoughts. If I could find a
certificated optical flow monitoring device, I would install it using part 43 as
data. No sweat at all!
While I do not have any desire to install more sensors in my fuel tanks, I
agree that Part 43 substantiation should work there.
Thanks again to all who have responded. It really helps flesh out the
answer.
Happy Skies,
Old Bob
AKA
Bob Siegfried
Bob's Aircraft Service
Downers Grove, IL
Stearman N3977A (and others)
In a message dated 4/21/2010 9:29:14 A.M. Central Daylight Time,
nuckolls.bob(at)aeroelectric.com writes:
At 08:08 AM 4/21/2010, you wrote:
Good Morning Joe,
Another great idea! This list is resourceful.
For my purposes, the fuel gauge I have does a good job as far as telling
me when my usable fuel is out of the tank. Admittedly, there are times when
four or five minutes of fuel will make a difference and if the flight is
planned to land with the FAA suggested thirty minute minimum planned fuel
reserve, five more minutes will make a difference to me.
However, I rarely cut fuel that close so my effort is oriented more toward
reducing the time the pump will be operating dry. That is why I am more
interested in finding out when the pump is pumping nothing but air. So far,
the best answer appears to be the optical monitoring of fuel flow. I
originally thought pressure would do the trick, but as many have pointed out,
there may not be enough head pressure to allow consistent measurable
differences.
When the idea of measuring current required by the pump surfaced, that
seemed to have merit, but 'Lectric Bob seems to feel that may not be a useful
measurement.
I've researched the evolution of the thump-thump pumps
and found quite a cache of history in the patent files.
A selection of examples have been posted at:
_http://aeroelectric.com/Mfgr_Data/Pumps/
_ (http://aeroelectric.com/Mfgr_Data/Pumps/) It seems our old friend the
"Bendix electric
pump" is well represented and appears to have been
taken over by Facet. An example of the Facet cube
pump is including. All of these are "solid state"
versions of the original design that simply used a
set of contacts to control the solenoid coil current
to re-stroke the pump. I was surprised to find
that "solid state" went back so far. The 1968
Bendix patent still has the mechanical switch
contacts but uses transistors to buffer the coil
current so that the contacts don't erode electrically.
Later versions use hall effect devices to sense
plunger position. The surprise was to find a
couple of designs that used a free-running
oscillator (555 timer) to simple pulse the
solenoid periodically. No plunger position
sensing at all.
It's possible that some versions will present
a unique current signature that could be used
to detect when the pump was running unloaded
but you'd have to do some all-conditions,
all-variables studies to make sure that your
sensing scheme did not risk false indications.
I think the pressure and electron measurement solutions are worthy of some
breadboard testing, but that optical monitoring of the fuel looks like a
winner.
Back in the summer of 08 we had some discussion here
on the list about optical liquid level sensors. These
have a rich history of practical application in automotive
applications dating back to the 1950's.
Modern incarnations include a series of devices
I was responsible for at Electro-Mech in the 80's
that have been built by the thousands and incorporated
into dozens of applications on Beech/RAC/Hawker-Beech
products. Here's a collection of pictures that
show features and products in the optical liquid
level sensors technology:
_http://aeroelectric.com/Pictures/Fuel_Level/
_ (http://aeroelectric.com/Pictures/Fuel_Level/) Gem Sensors is a good
place to start for
commercial off-the-shelf devices. They're
quite rugged and entirely suited to the
task.
_http://www.gemssensors.com/content.aspx?id=282_
(http://www.gemssensors.com/content.aspx?id=282)
Unfortunately, I now have to figure out a way of getting my local FED to
agree that it is a good solution.
You're not proposing to do anything new,
daring and fraught with risk. Successful
integration of these devices into a tank
have only to do with mundane issues of
craftsmanship that go to keeping the fuel
inside the pipes . . . i.e. leaks.
The neat thing about sensing absolute
level in the tank is the "dipstick" accuracy
of the value. There are no variables of
calibration associated with setting trip
points to light indicators from fuel
level transmitters, etc.
I could see a 337 mod to add the sensor
to the side of a tank. It's an ADDITION
that is an operating convenience and
has no effect on the basis for certification
for the original TC. Risks are limited to
issues of good shop practice and craftsmanship.
Bob . . .
________________________________________________________________________________
| From: | "John Burnaby" <jonlaury(at)impulse.net> |
| Subject: | Re: Facet pumps: Energy vs. Flow |
Check out Gems Sensors and this optical sensor:
http://www.gemssensors.com/content.aspx?id=5432
I got one off of Ebay for $5. When it "sees" fluid, it will sink 40ma to
drive a relay coil that closes the circuit on the Facet. I'm using this
same setup to power a Facet transfer pump. SPST switch to power Optical
sensor switch, to power relay, to power FACET and LED "On".
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <nuckolls.bob(at)aeroelectric.com> |
| Subject: | Future of general aviation |
At 12:29 PM 4/20/2010, you wrote:
Bob,
Pardon me for butting in, but from my experience with certificated
airplanes, it is virtually impossible to get a field approval like
you're after.
I used to have a 1961 Cessna 172, with an O-300 Continental. On
those hot mid-summer California days (100+), my oil temps got well
into the red on climbout!! I checked the accuracy of the gauge, and
it was correct!
Therefore, I wanted to add an oil cooler to my Cessna 172. It
didn't come with one, but I could get a later model 172 oil cooler to
fit. I sent off my Form 337 to the local FSDO, and their first
reaction was "NO!" Their attitude was "if it didn't come with one,
it doesn't need one!!"
I was irritated (to say the least), and requested an appeal. They
finally relented and said it would be okay. For crying out loud , it
was just an oil cooler!! (all certified parts, too)
My opinion is; there ain't no way you can legally add any kind of
permanent parts to modify to your fuel pump, fuel lines, or anything
else, on a certificated airplane, without that approved 337.
Just my opinion.................
An opinion not without foundation. Without telling
stories on anyone, I can share that I attended a
meeting yesterday. This was a gathering of technically
competent, talented integrators of simple-ideas into
elegant solutions. They were stampeded into a "solution"
the crippled the capability of perfectly good system
just to cover a flight condition that was easily
managed . . . all in the name of achieving "FAA
certification".
I pissed off some of the attendees . . . may
have lost future business for that customer.
Present trends plotted into the future do not
bode well for our beloved airplanes and the
people who design, build and fly them. We
have ever increasing numbers of people who
do not design, build and fly demanding to run
the show . . . all in the cause of "making
airplanes safer".
Bob . . .
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <nuckolls.bob(at)aeroelectric.com> |
| Subject: | Re: High fuel pressure |
At 10:46 AM 4/21/2010, you wrote:
>
>Folks,
>
>Re-posting from VAF, no joy over there but hope there might be
>someone here with an idea...
>
>Normally my fuel pressure with the mech pump runs 30-35 psi and with
>the boost on goes to 40-ish. Suddenly the other day I got a warning
>on my GRT EFIS when the pressure went to 190 psi and that has
>continued since, so am very reluctant to fly until this is sorted
>out. No engine stumbles or anything otherwise abnormal. Fuel flow is fine.
>
>This is an injected Bendix system on an IO-360 with 160 trouble free
>hours since new.
>
>I've never heard of this before, so if anyone here has ideas,
>advice, answers, please respond.
>
>BTW, I love that the EFIS picked this out for me and sent up the
>flag, very handy.
Is the pump really capable of that kind of pressure?
A failure of a relief valve might account for an
unexpected rise in pressure but I'd be suspicious
of the EFIS pressure transducer too. It's MUCH
more complicated than that spring-loaded relief
valve. Double check with a simple dial-gauge.
Bob . . .
________________________________________________________________________________
| From: | Doug Ilg <doug.ilg(at)verizon.net> |
| Subject: | Re: High fuel pressure |
Have you (re-)checked the accuracy of the sensor?- Did you accidentally c
hange a calibration factor in the EFIS?- That's a HUGE jump.=0A-=0ADoug
Ilg=0AGrumman Tiger N74818, College Park-Airport (KCGS), Maryland=0AChal
lenger II LSS LW (N641LG-reserved)-- kit underway at Laurel Suburban (W
18)=0A=0A-=0A=0A=0A>=0A>From: "jerry2dt(at)aol.com" <jerry2dt(at)aol.com>=0A>To
: aeroelectric-list(at)matronics.com=0A>Sent: Wed, April 21, 2010 11:46:44 AM
=0A>Subject: AeroElectric-List: High fuel pressure=0A>=0A>=0A______________
__________________=0A=0A>Folks,=0A>=0A>Re-posting from VAF, no joy over the
re but hope there might be someone here with an idea...=0A>=0A>Normally my
fuel pressure with the mech pump runs 30-35 psi and with the boost on goes
to 40-ish. Suddenly the other day I got a warning on my GRT EFIS when the p
ressure went to 190 psi and that has continued since, so am very reluctant
to fly until this is sorted out. No engine stumbles or anything otherwise a
bnormal. Fuel flow is fine. =0A>
________________________________________________________________________________
| Subject: | Surface temperature sensor |
Q,
Has anyone come across an example of a surface temperature sensor
(generic)) that could be used on engine parts or perhaps the firewall
and send a digital reading back to the panel?
Example. - I would like to measure the temperature on the surface of my
oil filter/fuel pump and display that value on the panel.
FYI - I have stick-on thermometers that work great when performing
engine checks on the ground but they are of little use in the air.
Thanks,
Glenn
________________________________________________________________________________
| From: | Mike Welch <mdnanwelch7(at)hotmail.com> |
| Subject: | RE: Designing a circuit question |
'Lectric Bob=2C
I REALLY like your circuit design regarding the IvoProp motor. In fact
=2C I'm planning on building one=2C seeing as how I have an IvoProp...with
the motor.
If I understand the process correctly=2C by pushing the dpdt switch=2C wh
en the motor sees 6 A current=2C the LED will light up. Let go of the dpdt
switch quickly=2C and you're in like Flynn.
Here's my question: would it be much of a challenge for the motor to lig
hten multiple LEDs (in both directions)=2C as it cycles from 0 to 10A? Of
course=2C you'd want two separate circuits indicating if you're headed to f
lat pitch...or steep pitch=2C or some method to insure you're twisting the
prop in the correct direction you intended to.
Wouldn't this design I'm asking about be essentially an analog version of
a current meter? Example: say you're at zero pitch=2C and you cycle tow
ard steep pitch. As the motor's current draw increases=2C it could light a
1A LED=2C then a 2A LED=2C a 3A LED=2C etc=2C etc.
Same process for the other prop twist.
If a guy had this type of design he could routinely set his prop pitch to
a known LED position to achieve maximum value of a variable pitch prop. H
e could adjust his engine and prop (LED) to a known performance characteris
tic.....i.e......engine rpm 4750=2C pitch in the steep direction #5 LED.
Thanks for your ideas!
Mike Welch
BTW. I built that copper tape groundplane antenna. It works great so far
=2C but I'm waiting on the bnc connector/PL 259 adapter for the SWR meter t
o adjust it correctly (Radio Shack Friday's delivery)!!
_________________________________________________________________
The New Busy is not the old busy. Search=2C chat and e-mail from your inbox
.
http://www.windowslive.com/campaign/thenewbusy?ocid=PID28326::T:WLMTAGL:O
N:WL:en-US:WM_HMP:042010_3
________________________________________________________________________________
| From: | "mike gamble" <mp.gamble(at)talktalk.net> |
| Subject: | Battery replacement in Garmin 3 pilot |
Has anybody had experience replacing the memory battery in the old Garmin 3
pilot GPS. Is it straight forward and is the battery easily obtained in UK?
I'm reluctant to discard what has been a trusty old companion over many
years, for the sake of a bit of diy tinkering.
Thanks
Mike
XS mono
G-CFMP
________________________________________________________________________________
| Subject: | Re: Surface temperature sensor |
| From: | "rampil" <ira.rampil(at)gmail.com> |
Ahhhh, how bout a thermocouple? how bout a resistive probe like
many engines use for CHT. This discussion group is replete with temp.
monitoring
--------
Ira N224XS
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=295140#295140
________________________________________________________________________________
| From: | "The Kuffels" <kuffel(at)cyberport.net> |
| Subject: | Re: Accurate Altitude and Airspeed |
Sam,
<< Dynon FlightDek ... winds aloft display ... pretty inaccurate ...
look after my static ports ... investigating the wedges at the static
ports. >>
If you wish, I have an Excel spreadsheet which will help you measure the
accuracy of your pitot/static system. For various indicated airspeeds
and pressure altitudes (set your altimeter to 29.92) you fly an
approximate box course noting the GPS track and groundspeed. (Also note
temperature for later use.) Enter the 4 data points and the spreadsheet
calculates 4 true airspeed and wind values. The 4th, redundant,
datapoint allows an internal quality check since the 4 calculated air
and wind speeds should be very close to each other. Discard any
measurement which isn't.
Knowing true airspeed, pressure altitude and temperature do a "reverse"
E-6B calculation to determine what your indicated airspeed *should* have
been. Graphs of errors for constant indicated airspeeds vs altitudes
and constant altitudes vs airspeeds will give you an excellent view of
system/instrument errors. Not only can you determine even subtle
effects of any changes to your pitot/static system but when you are done
you have accurate graphs of true vs indicated airspeeds.
This is an exercise everyone should do as part of any homebuilt test
period.
Email me direct off-list for a copy of the spreadsheet:
kuffel(at)cyberport.net
Tom Kuffel
EAA Flight Advisor
________________________________________________________________________________
| Subject: | Re: Surface temperature sensor |
| From: | "rampil" <ira.rampil(at)gmail.com> |
The actual sensors for t/c or thermistors are tiny inside those cans
they get mounted in. A tc is just two wires twisted in each other.
Either is easy to JB Weld in place on a surface
--------
Ira N224XS
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=295168#295168
________________________________________________________________________________
| From: | "Dennis & Anne Glaeser" <glaesers(at)wideopenwest.com> |
| Subject: | RE: RE: Designing a circuit question |
See my comments after the ----->'s below...
RE: RE: Designing a circuit question
From: Mike Welch
I REALLY like your circuit design regarding the IvoProp motor. In fact I'm
planning on building one seeing as how I have an IvoProp...with the motor.
If I understand the process correctly by pushing the dpdt switch when the
motor sees 6A current the LED will light up. Let go of the dpdt switch
quickly and you're in like Flynn.
------->
Yup! Not only does the LED illuminate, the current to the motor is limited,
so it may stop before reaching the physical stop if twisting the blade is
loading the motor enough. That's why I was asking about adjusting the
trigger amperage. We don't want the circuit limiting the pitch too much.
-----------------
Here's my question: would it be much of a challenge for the motor to
lighten multiple LEDs (in both directions) as it cycles from 0 to 10A? Of
course you'd want two separate circuits indicating if you're headed to flat
pitch...or steep pitch or some method to insure you're twisting the prop in
the correct direction you intended to.
---------->
The light will come on whenever the trigger amperage is reached as you note
above. Direction (toward high or low pitch) depends on which way the switch
is moved. Bob's circuit sees current in the same direction all the time,
the switch is where it is reversed for the motor.
----------------------
Wouldn't this design I'm asking about be essentially an analog version of a
current meter? Example: say you're at zero pitch and you cycle toward steep
pitch. As the motor's current draw increases it could light a 1A LED then a
2A LED a 3A LED etc etc.
If a guy had this type of design he could routinely set his prop pitch to a
known LED position to achieve maximum value of a variable pitch prop. He
could adjust his engine and prop (LED) to a known performance
characteristic.....i.e......engine rpm 4750 pitch in the steep direction #5
LED.
-------->
A number of IVO users have put an ammeter in the circuit to do what you
suggest by simply reading the meter instead of watching LEDs. Direction is
which way you move the switch, the ammeter works the same in both
directions.
-------------
Same process for the other prop twist.
---------->
No, the current to the switch is always in the same direction. You'd have
to put something on in the lines to the motor to be able to sense which way
the motor is being driven.
-------------
Dennis Glaeser
________________________________________________________________________________
| From: | Mike Welch <mdnanwelch7(at)hotmail.com> |
| Subject: | RE: RE: Designing a circuit question |
Dennis=2C
Upon close inspection of the current in Bob's design=2C yup=2C you're rig
ht about the current direction.
Back to my idea. I suppose the ammeter might not be too bad of a directi
on to go=2C but I still like the idea of a line of 5-6 LEDs=2C which is an
indication of the prop's motor current load. Would this be a simple circu
it=2C and very importantly=2C can it be a modification to the one Bob came
up with? I can sure see an advantage to a combo circuit.....one that show
s you visually that you are increasing the current=2C and eventually the fi
nal LED=2C indicating near max current?
Mike Welch
_________________________________________________________________
The New Busy is not the old busy. Search=2C chat and e-mail from your inbox
.
http://www.windowslive.com/campaign/thenewbusy?ocid=PID28326::T:WLMTAGL:O
N:WL:en-US:WM_HMP:042010_3
________________________________________________________________________________
| Subject: | Re: S704-1 on Hot Side of Firewall? |
| From: | "Noah" <sgninc(at)cox.net> |
Thanks Bob. Prior to your response, I moved the battery bus and E-bus relay south
of the firewall on my schematic. I think I like that better anyway. Roughly
the same number of wires transiting the firewall feed-thru. Does require
a fusible link on the battery bus feed however.
--------
Highest Regards,
Noah Forden
RV-7A
Rhode Island
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=295213#295213
________________________________________________________________________________
| From: | Speedy11(at)aol.com |
| Subject: | Re: The Miracle Whip series antennae |
Keith,
What kind of aircraft? Where did you mount? Did you have to run coax?
Does it work with VHF comm and VOR signals?
I've never heard of this antenna before.
Inquiring minds want to know.
Stan Sutterfield
Folks;
>From the 'for what it's worth' dept --
I bought a plane that had a standard Comant antenna mounted on the bottom
on
an almost all metal plane. Sitting on the ground, I was unable to receive
weather. I replaced that antenna with a miracle whip placed in a small
fiberglass portion of the plane at about the same distance from the ground.
I was amazed at the results in reception and also the cleanliness of
reception. Friends told me my radio coms were crystal clear. I am a happy
Miracle Whip user. The antenna is also in one piece, so if you dont glue it
in place, it will serve as a great rubber duck replacement for a handheld.
-- Keith
________________________________________________________________________________
| Subject: | Alternator field feed - fuse vs. fusible link |
| From: | "Noah" <sgninc(at)cox.net> |
I understand why a fusible link is specified in line with the 5A breaker for alternator
field feed. The breaker is designed to trip when the regulator grounds
the feed in case of bus overvoltage. And I understand that the fusible link
protects the wire from the bus to the breaker from a dead short. But if you're
using the B&C fuseblocks, why not just stick a 30A fuse in there in place
of the fusible link? Seems like it would also be robust, the breaker would still
trip in case of overvoltage, and you wouldn't need to fabricate a custom fusible
link?? In my case I have several wires being ganged together at the fuseblock
terminal and this approch would eliminate one of them!
I know I must be missing something here, just don't know what!
--------
Highest Regards,
Noah Forden
RV-7A
Rhode Island
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=295217#295217
________________________________________________________________________________
| From: | "rckol" <rckol(at)kaehlers.com> |
Some of you toiling to understand the whys and wherefores of the Z diagrams might
also enjoy this bit of silliness:
http://www.xkcd.com/730/
--------
rck
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=295219#295219
________________________________________________________________________________
| From: | <robert.mccallum2(at)sympatico.ca> |
| Subject: | Alternator field feed - fuse vs. fusible link |
The "dead short" on this circuit when (if) the crowbar circuit operates cou
ld quite easily "blow" the 30 Amp fuse before or while tripping the 5A brea
ker. The time constants for breakers and fuses are significantly different.
To do as you suggest would work but at the risk of having to replace a fus
e before being able to bring the alternator back on line. The suggested met
hod has been well thought out and all failure modes taken into account. It'
s the way it is for good reason.
Just a quick anecdotal story to illustrate. Many moons ago in electric moto
rs lab=2C a fellow student made a wiring error when connecting a motor for
"plugging" it to a stop. (Plugging a motor involves removing the line power
then shorting the motor to cause it to stop quickly) Long story short he c
onnected the plugging relay across the three phase line instead of across t
he motor. When the "stop" button was pressed=2C the 25 amp test bench break
er tripped=2C the 125 amp lab supply breaker tripped=2C the 400 amp breaker
supplying the whole floor of the school tripped=2C and the 800 amp main in
coming breaker to the building tripped. Maybe unusual=2C but happened.
Bob McC
> -----Original Message-----
> From: owner-aeroelectric-list-server(at)matronics.com [mailto:owner-aeroelec
tric-list-
> server(at)matronics.com] On Behalf Of Noah
> Sent: Wednesday=2C April 21=2C 2010 11:11 PM
> To: aeroelectric-list(at)matronics.com
> Subject: AeroElectric-List: Alternator field feed - fuse vs. fusible link
>
>
> I understand why a fusible link is specified in line with the 5A breaker
for alternator
> field feed. The breaker is designed to trip when the regulator grounds t
he feed in
> case of bus overvoltage. And I understand that the fusible link protects
the wire from
> the bus to the breaker from a dead short. But if you're using the B&C fu
seblocks=2C why
> not just stick a 30A fuse in there in place of the fusible link? Seems l
ike it would also
> be robust=2C the breaker would still trip in case of overvoltage=2C and y
ou wouldn't need
> to fabricate a custom fusible link?? In my case I have several wires bei
ng ganged
> together at the fuseblock terminal and this approch would eliminate one o
f them!
>
> I know I must be missing something here=2C just don't know what!
>
> --------
> Highest Regards=2C
>
> Noah Forden
> RV-7A
> Rhode Island
>
>
>
>
> Read this topic online here:
>
> http://forums.matronics.com/viewtopic.php?p=295217#295217
>
>
>
>
>
>
>
> _-
> ========================
==
> =======
> _-
> ========================
==
> =======
> _-
> ========================
==
> =======
> _-
> ========================
==
> =======
>
>
________________________________________________________________________________
| Subject: | Re: Future of general aviation |
| From: | Paul Kuntz <paul.r.kuntz(at)gmail.com> |
I've been an engineer and program manager at Boeing for thirty-two years,
and am continually surprised to see how few of my fellow employees are
actually interested in aviation. Yesterday I sat in a room with about
thirty other engineers who are working on a new US Navy aircraft, for a
get-acquainted session with the new manager of the 200-member team that is
building the mission electronics system for that aircraft. We went around
the room for everyone to discuss their background and their outside
interests. I was the only person in the room, including the group manager,
who expressed any interest at all in airplanes and flying. This has been a
pattern throughout my career, but I do find that my experience as a pilot
and aircraft builder has generated wide respect for my opinion on the way to
approach or solve a problem.
Boeing does acknowledge the value of pilot experience in its work force, and
provides a subsidy of $500 for non-pilots on achieving first solo, and
another $500 on achieving a Private Pilot rating. Nevertheless, there seem
to be far too few real airplane enthusiasts among the employees of a company
that is known primarily as a supplier of a very large portion of the world's
fleets of commercial airliners, not to mention many military aircraft. I
call daily on my lifelong experience building model aircraft, my 40+ years
membership in EAA, my personal pursuit of commercial, multi-engine,
instrument, glider and CFI ratings, and my hands-on building of two
homebuilt aircraft. There's simply nothing to replace true passion for
aviation in the pursuit of practical, useful solutions for the problems
encountered in the development of the next generation of aircraft.
We all need to contribute to the continuance of this legacy by supporting
programs like Young Eagles, encouraging youth who express interest in what
we do, participating in information exchange forums like this one, and never
taking the privilege of flying for granted.
Regards,
Paul Kuntz
http://www.pipistrelbuilders.com
On Wed, Apr 21, 2010 at 8:54 AM, Robert L. Nuckolls, III <
nuckolls.bob(at)aeroelectric.com> wrote:
> nuckolls.bob(at)aeroelectric.com>
>
> At 12:29 PM 4/20/2010, you wrote:
> Bob,
>
> Pardon me for butting in, but from my experience with certificated
> airplanes, it is virtually impossible to get a field approval like you're
> after.
>
> I used to have a 1961 Cessna 172, with an O-300 Continental. On those hot
> mid-summer California days (100+), my oil temps got well into the red on
> climbout!! I checked the accuracy of the gauge, and it was correct!
>
> Therefore, I wanted to add an oil cooler to my Cessna 172. It didn't come
> with one, but I could get a later model 172 oil cooler to fit. I sent off
> my Form 337 to the local FSDO, and their first reaction was "NO!" Their
> attitude was "if it didn't come with one, it doesn't need one!!"
>
> I was irritated (to say the least), and requested an appeal. They finally
> relented and said it would be okay. For crying out loud , it was just an
> oil cooler!! (all certified parts, too)
>
> My opinion is; there ain't no way you can legally add any kind of
> permanent parts to modify to your fuel pump, fuel lines, or anything else,
> on a certificated airplane, without that approved 337.
>
> Just my opinion.................
>
> An opinion not without foundation. Without telling
> stories on anyone, I can share that I attended a
> meeting yesterday. This was a gathering of technically
> competent, talented integrators of simple-ideas into
> elegant solutions. They were stampeded into a "solution"
> the crippled the capability of perfectly good system
> just to cover a flight condition that was easily
> managed . . . all in the name of achieving "FAA
> certification".
>
> I pissed off some of the attendees . . . may
> have lost future business for that customer.
>
> Present trends plotted into the future do not
> bode well for our beloved airplanes and the
> people who design, build and fly them. We
> have ever increasing numbers of people who
> do not design, build and fly demanding to run
> the show . . . all in the cause of "making
> airplanes safer".
>
> Bob . . .
>
>
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <nuckolls.bob(at)aeroelectric.com> |
| Subject: | RE: Designing a circuit question |
At 01:34 PM 4/21/2010, you wrote:
>'Lectric Bob,
>
> I REALLY like your circuit design regarding the IvoProp
> motor. In fact, I'm planning on building one, seeing as how I have
> an IvoProp...with the motor.
>
> If I understand the process correctly, by pushing the dpdt
> switch, when the motor sees 6 A current, the LED will light
> up. Let go of the dpdt switch quickly, and you're in like Flynn.
Yes, the motor will see pretty much full bus
voltage until it's draw exceeds the set-point for
the current limiter. The votlage to the motor is
reduced at that point to maintain a max current
equal to setpoint. If that value is too low, it
can be increased by paralleling the .1 ohm reistor
with additional resistors as I described earlier
today.
>
> Here's my question: would it be much of a challenge for the
> motor to lighten multiple LEDs (in both directions), as it cycles
> from 0 to 10A? Of course, you'd want two separate circuits
> indicating if you're headed to flat pitch...or steep pitch, or some
> method to insure you're twisting the prop in the correct direction
> you intended to.
That's a given depending on your switch. It's a spring
loaded center off with one direction for increased pitch
and the opposite direction for flatter pitch.
> Wouldn't this design I'm asking about be essentially an analog
> version of a current meter? Example: say you're at zero pitch,
> and you cycle toward steep pitch. As the motor's current draw
> increases, it could light a 1A LED, then a 2A LED, a 3A LED, etc, etc.
>Same process for the other prop twist.
No, it doesn't work that way. This light comes on only
when the motor stalls against the stop at either max
or min pitch. It's not intended to be a pitch value
indicator.
>
> If a guy had this type of design he could routinely set his prop
> pitch to a known LED position to achieve maximum value of a
> variable pitch prop. He could adjust his engine and prop (LED) to
> a known performance characteristic.....i.e......engine rpm 4750,
> pitch in the steep direction #5 LED.
I doubt that exact pitch is that tightly
associated with motor current. However, it wouldn't
be too hard to build a constant speed controller
not unlike that electro-mechanical prop-pitch
controller on the old Bonanzas . . . except
this one would work better.
It would be slow . . . but it could be quite
accurate. When you increased manifold pressure
at some prop pitch setting, you would see an immediate
increase in rpm but it would come back to the set-point
a few seconds after the power increase.
I'm fiddling with a variant of the circuit I
published to convert it to a solid state breaker
instead of current limiter. In this case, you
wouldn't need any heat sink because the device
would be in the current limited mode for a few
tens of milliseconds.
I'll see if I can publish that variant tomorro evening.
Bob . . .
________________________________________________________________________________
| From: | <bakerocb(at)cox.net> |
| Subject: | High fuel pressure |
4/22/2010
Hello Jerry, Like other suggestions I suggest that you look to the fuel
pressure transducer.
The fuel pressure on my TCM IO-240 B9B engine suddenly went from the 9 PSI
range to 54 PSI as reported by my Vision Microsystems engine data
instrumentation system.
In the process of disconnecting the transducer electrical plug for trouble
shooting and reconnecting it the problem disappeared. Evidently some
vibration or corrosion had opened one of the four connections.
The trouble shooting and self curing saved me $400.00 for a new transducer.
'OC' Says: "The best investment we can make is the effort to gather and
understand knowledge."
===================================================
Subject: AeroElectric-List: High fuel pressure
From: jerry2dt(at)aol.com
Folks,
Re-posting from VAF, no joy over there but hope there might be someone her
e with an idea...
Normally my fuel pressure with the mech pump runs 30-35 psi and with the
boost on goes to 40-ish. Suddenly the other day I got a warning on my GRT
EFIS when the pressure went to 190 psi and that has continued since, so
am very reluctant to fly until this is sorted out. No engine stumbles or
anything otherwise abnormal. Fuel flow is fine.
This is an injected Bendix system on an IO-360 with 160 trouble free hours
since new.
I've never heard of this before, so if anyone here has ideas, advice, answ
ers, please respond.
BTW, I love that the EFIS picked this out for me and sent up the flag, ver
y handy.
Thanks all,
Jerry Cochran
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <nuckolls.bob(at)aeroelectric.com> |
| Subject: | Re: Diode confusion |
>My question:
>
>For a functioning diode, shouldn't current flow from the red lead of
>the multimeter when it's placed on the non-band side of the diode,
>to the black lead of the multimeter when it's on the band-side of
>the diode and indicate zero (or very little resistance)?
>
>Thanks to whoever can set me straight on this ridiculously simple concept.
Not all multimeters are the same. I have instruments
wherein the electron-flows are reversed from each other.
While the exercise you describe is a learning moment,
the last time I saw a "bad" diode either in terms of
markings or electrical condition was many moons ago.
Just know that there is no "standard" for choosing
polarity of a multimeter's resistance measurement
current.
Bob . . .
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <nuckolls.bob(at)aeroelectric.com> |
| Subject: | Re: S704-1 on Hot Side of Firewall? |
At 10:03 PM 4/21/2010, you wrote:
>
>Thanks Bob. Prior to your response, I moved the battery bus and
>E-bus relay south of the firewall on my schematic. I think I like
>that better anyway. Roughly the same number of wires transiting the
>firewall feed-thru. Does require a fusible link on the battery bus
>feed however.
. . . on the battery bus feed? Fusible links are
ROBUST protection on the order of ANL type current
limiters and should not be used in an always-hot feed
from a battery. Everything coming off the battery
should be a 7A or less fuse except where you need
a robust alternate path for the e-bus. In that case,
the battery bus fuse size goes up accordingly but the
e-bus relay becomes a "mini battery contactor" for
the e-bus . . . and should be as close as practical
to the battery bus.
Bob . . .
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <nuckolls.bob(at)aeroelectric.com> |
| Subject: | RE: RE: Designing a circuit question |
At 08:50 PM 4/21/2010, you wrote:
>Dennis,
>
> Upon close inspection of the current in Bob's design, yup, you're
> right about the current direction.
>
> Back to my idea. I suppose the ammeter might not be too bad of a
> direction to go, but I still like the idea of a line of 5-6 LEDs,
> which is an indication of the prop's motor current load. Would
> this be a simple circuit, and very importantly, can it be a
> modification to the one Bob came up with? I can sure see an
> advantage to a combo circuit.....one that shows you visually that
> you are increasing the current, and eventually the final LED,
> indicating near max current?
There are integrated circuits designed to
drive a totem pole of leds. They're common
to many audio systems where a solid state
"VU Meter" is implemented with a gaggle of
leds. See:
http://www.national.com/ds/LM/LM3915.pdf#page=1
You would need a shunt, an op-amp signal
conditioner and the LM3915. This is not
a trivial task to configure. The analog meter
and shunt would be much simpler to implement.
One of our miniature loadmeters could be combined
with a custom shunt.
Bob . . .
________________________________________________________________________________
| From: | "Glaeser, Dennis" <dennis.glaeser(at)hp.com> |
| Subject: | RE: RE: RE: Designing a circuit question |
Mike,
I think there are ammeters that have LED indicators - but I am definitely NOT the
expert on such things. It wouldn't be a mod to Bob's circuit. You could have
both an ammeter to show the increasing current and Bob's circuit to indicate
and limit max current.
Dennis
----------------------------------------------------
From: Mike Welch
Dennis,
Upon close inspection of the current in Bob's design, yup, you're right about the
current direction.
Back to my idea. I suppose the ammeter might not be too bad of a direction to
go, but I still like the idea of a line of 5-6 LEDs, which is an indication of
the prop's motor current load. Would this be a simple circuit, and very importantly,
can it be a modification to the one Bob came up with? I can sure see
an advantage to a combo circuit.....one that shows you visually that you are
increasing the current, and eventually the final LED, indicating near max current?
Mike Welch
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <nuckolls.bob(at)aeroelectric.com> |
| Subject: | Re: Future of general aviation |
>We all need to contribute to the continuance of this legacy by
>supporting programs like Young Eagles, encouraging youth who express
>interest in what we do, participating in information exchange forums
>like this one, and never taking the privilege of flying for granted.
I fear that the inoculation for indifference may be more
complicated that enthusiastic offers of airplane rides.
Our culture is slowly loosing its curiosity and excitement
as to how and why things work. There's more interest in
stepping up to the next revision of "Borg Wars" or
seeking out the most outrageous roller coaster. The
perpetual quest for transient pleasures is winning out
over the joy of finding things out.
Young Eagles is a fine idea but it's also a "process"
enthusiastically endorsed by folks who think education
is "flip switch A, insert tab C into slot D, watch
video F, etc".
Real teaching is a meeting of the minds, an exchange
of concepts and a study of recipes for success crafted
of simple-ideas.
My grandson doesn't know what he's in for. We're going
to cook, grow, build, design, cut metal, photoshop,
autocad, cut wood, take things apart, put them back
together and explore the simple-ideas that are discovered
in the process. Exactly how he uses these experiences
will ultimately be up to him. But without having peeked
behind all those doors, how can he make well considered
choices?
Our contemporaries have, I suspect, not peeked behind
many doors . . . their teachers (which includes EVERY
adult interaction in their younger lives) have failed
them. I have the signatures of more than 50 young eagles
in my logbook . . . I'll bet not one of them has set
foot back in an airplane . . . unless it was at the
NEXT air show where free rides were offered again.
That "privilege" thing is closely related to what
doors have been peeked into. Present trends plotted
into the future suggest that ANY privilege we now
enjoy can disappear any time with the mere stroke
of a pen in Washington.
Bob . . .
________________________________________________________________________________
| From: | "David LLoyd" <skywagon(at)charter.net> |
| Subject: | Re: Future of general aviation |
The simple truth of things was elegantly set in your words....Thanks.
However, too few will read nor understand. And, even fewer will act.
Unfortunately, it covers more than just future aviation.
Now we know what probably happened to the Romans, even after removing the
influence of their lead pipe system from the equation.
----- Original Message -----
From: "Robert L. Nuckolls, III" <nuckolls.bob(at)aeroelectric.com>
Sent: Thursday, April 22, 2010 7:51 AM
Subject: Re: AeroElectric-List: Future of general aviation
>
>
>
>>We all need to contribute to the continuance of this legacy by supporting
>>programs like Young Eagles, encouraging youth who express interest in what
>>we do, participating in information exchange forums like this one, and
>>never taking the privilege of flying for granted.
>
> I fear that the inoculation for indifference may be more
> complicated that enthusiastic offers of airplane rides.
> Our culture is slowly loosing its curiosity and excitement
> as to how and why things work. There's more interest in
> stepping up to the next revision of "Borg Wars" or
> seeking out the most outrageous roller coaster. The
> perpetual quest for transient pleasures is winning out
> over the joy of finding things out.
>
> Young Eagles is a fine idea but it's also a "process"
> enthusiastically endorsed by folks who think education
> is "flip switch A, insert tab C into slot D, watch
> video F, etc".
>
> Real teaching is a meeting of the minds, an exchange
> of concepts and a study of recipes for success crafted
> of simple-ideas.
>
> My grandson doesn't know what he's in for. We're going
> to cook, grow, build, design, cut metal, photoshop,
> autocad, cut wood, take things apart, put them back
> together and explore the simple-ideas that are discovered
> in the process. Exactly how he uses these experiences
> will ultimately be up to him. But without having peeked
> behind all those doors, how can he make well considered
> choices?
>
> Our contemporaries have, I suspect, not peeked behind
> many doors . . . their teachers (which includes EVERY
> adult interaction in their younger lives) have failed
> them. I have the signatures of more than 50 young eagles
> in my logbook . . . I'll bet not one of them has set
> foot back in an airplane . . . unless it was at the
> NEXT air show where free rides were offered again.
>
> That "privilege" thing is closely related to what
> doors have been peeked into. Present trends plotted
> into the future suggest that ANY privilege we now
> enjoy can disappear any time with the mere stroke
> of a pen in Washington.
>
> Bob . . .
>
>
>
________________________________________________________________________________
| From: | Lincoln Keill <airlincoln(at)sbcglobal.net> |
Bob S. --
Thanks for the great tip -- I haven't been to the EAA site for some time an
d those instructional videos are fantastic. -I watched all of the ones un
der the "Electrical" tab plus a few more and learned a bunch...wish I'd don
e that a lot earlier. -These videos are the perfect complement to the AEC
-- being able to actually watch someone demonstrate the correct way to cri
mp a BNC connector onto a piece of RG-58, solder a wire onto a switch (pre-
tinning wire...what a concept!), crimp on a molex connector pin and them re
move it from its housing, strip shielded cable, etc., etc. makes reading th
e AEC a more enjoyable and understandable experience.-
I always knew that alternators were lighter than generators, but never knew
that an alternator starts producing voltage around 700 RPM (compared to a
generator's cut-in speed of 1500 RPM) which is why we no longer have to dis
charge our batteries taxiing around at idle power. -Did you know there ar
e no special tools required to fabricate Aeroquip hoses?...I didn't until t
oday. -When you flare a tube, you should use lubricant identical to the f
luid the tubing will carry...never thought about that....makes sense. -Al
l in all, a great resource for those of us still on the steep side of the l
earning curve.
Thanks again Bob.
Linc
Check the EAA.ORG website under hints for homebuilders electrical.- They
have a
nice video with an instructor demonstrating exactly what you are asking abo
ut.
It will clear things up for you.-
Bob S.
________________________________________________________________________________
| Subject: | Re: Surface temperature sensor |
| From: | Dj Merrill <deej(at)deej.net> |
On 04/21/2010 01:42 PM, longg(at)pjm.com wrote:
> Has anyone come across an example of a surface temperature sensor
> (generic)) that could be used on engine parts or perhaps the firewall
> and send a digital reading back to the panel?
Tons of digital thermometers with remote wireless sensors are available
in Home and Garden sections of retail stores.
Not a recommendation, but here is one example:
http://www.amazon.com/Crosse-Technology-Digital-Thermometer-Wireless/dp/B001DNIIOS/ref=sr_1_2?ie=UTF8&s=home-garden&qid=1271961133&sr=8-2
<http://www.amazon.com/Crosse-Technology-Digital-Thermometer-Wireless/dp/B001DNIIOS/ref=sr_1_2?ie=UTF8&s=home-garden&qid=1271961133&sr=8-2>
Drop by your local Walmart, Home Depot, or Lowes and I'm sure you can
find plenty to choose from.
Probably not too hard to tear apart the remote sensor housing and get
to the actual sensor itself to attach it directly to something.
-Dj
--
Dj Merrill - N1JOV
Glastar Sportsman 2+2 Builder #7118 N421DJ - http://deej.net/sportsman/
Grumman Yankee Driver N9870L - http://deej.net/yankee/
________________________________________________________________________________
| Subject: | Re: RE: RE: RE: Designing a circuit question |
| From: | Dj Merrill <deej(at)deej.net> |
Ivo does offer a constant speed option which might be worth considering:
http://www.ivoprop.com/constant.htm
Building your own might be fun, too, and since I'm thinking of an
electric IVO I am also interested to see what you come up with. :-)
-Dj
________________________________________________________________________________
| From: | Mike Welch <mdnanwelch7(at)hotmail.com> |
| Subject: | Proper SWR meter |
Electric gurus=2C
I've got an SWR meter I borrowed from a neighbor who's a HAM radio buff.
The SWR meter is a Lafayette=2C stock no. 99-25835. I'm waiting for the b
nc/pl259 adapter to get here tomorrow=2C before I can use it. (It has the
bnc male/PL259 adapter to hook it up to my Icom A200).
It was suggested to me to make sure it is the "right frequency meter"=2C
to be able to properly check for standing waves. I wasn't aware of that as
pect of an SWR meter.
Does anyone know if this meter can properly check the standing waves on f
requencies of an aircraft radio/antenna? It only refers to "amateur ra
dio stations".
Thanks=2C
Mike Welch
_________________________________________________________________
The New Busy think 9 to 5 is a cute idea. Combine multiple calendars with H
otmail.
http://www.windowslive.com/campaign/thenewbusy?tile=multicalendar&ocid=
PID28326::T:WLMTAGL:ON:WL:en-US:WM_HMP:042010_5
________________________________________________________________________________
| Subject: | Re: Proper SWR meter |
| From: | Dj Merrill <deej(at)deej.net> |
On 04/22/2010 03:00 PM, Mike Welch wrote:
> The SWR meter is a Lafayette, stock no. 99-25835.
>
>
> Does anyone know if this meter can properly check the standing waves
> on frequencies of an aircraft radio/antenna? It only refers to
> "amateur radio stations".
I was unable to find the exact specs for this unit, but I found a forum
thread on it here:
http://forums.qrz.com/showthread.php?t=88199
If that thread is true, then if you are looking for a relative reading
(ie, a maximum or minimum reading), it might be okay. If you are
looking for an exact correct numerical reading, then no.
Typically, if you are tuning an antenna you are looking for a minimum
reading, so it would probably be okay. Tune, check SWR, tune, check
SWR, etc.
If you are inserting this inline to check the SWR reading of an
existing antenna installation and need an accurate number, then it
probably won't do you much good on aircraft freqs.
-Dj
--
Dj Merrill - N1JOV
Glastar Sportsman 2+2 Builder #7118 N421DJ - http://deej.net/sportsman/
Grumman Yankee Driver N9870L - http://deej.net/yankee/
________________________________________________________________________________
| From: | "J. Mcculley" <mcculleyja(at)starpower.net> |
| Subject: | Re: Surface temperature sensor |
I've been using a very inexpensive system with 18 sensor locations in my
Wittman Tailwind for well over 500 hours and 7 years, with never a
malfunction. It's based on inexpensive thermistors available from most
electronics suppliers and feeds into the display head of an ordinary
digital meat thermometer mounted on my instrument panel. It can handle
up to 300 degree F which covers everything firewall-forward except
engine cylinder EGT and CHT.
If you want some part numbers and more details contact me off list at
mcculleyja(at)starpower.net.
Jim McCulley
===================================================================================
longg(at)pjm.com wrote:
>
>
> Q,
>
>
>
> Has anyone come across an example of a surface temperature sensor
> (generic)) that could be used on engine parts or perhaps the firewall
> and send a digital reading back to the panel?
>
>
>
> Example. I would like to measure the temperature on the surface of my
> oil filter/fuel pump and display that value on the panel.
>
>
>
> FYI I have stick-on thermometers that work great when performing
> engine checks on the ground but they are of little use in the air.
>
>
>
> Thanks,
>
>
>
> Glenn
>
>
>
>
>
> *
>
>
> *
________________________________________________________________________________
| From: | Mike Welch <mdnanwelch7(at)hotmail.com> |
| Subject: | Proper SWR meter |
> Typically=2C if you are tuning an antenna you are looking for a minimum
> reading=2C so it would probably be okay. Tune=2C check SWR=2C tune=2C che
ck
> SWR=2C etc.
> -Dj
Thanks for the reply=2C DJ.
After reading some of those comments on it=2C now I'm concerned it may da
mage my Icom A200.
The antenna I was planning on checking with it is my recently constructed
"copper foil groundplane" antenna.
I have plugged the antenna into the radio=2C and the local airport unicom
replied with a "loud and clear"=2C but they are only 1/3 of a mile away.
Should I not risk screwing up my Icom=2C and try to find a more appropria
te SWR meter?
Thanks=2C
Mike Welch
GlaStar and Kolb MkIIIX builder
_________________________________________________________________
Hotmail is redefining busy with tools for the New Busy. Get more from your
inbox.
http://www.windowslive.com/campaign/thenewbusy?ocid=PID28326::T:WLMTAGL:O
N:WL:en-US:WM_HMP:042010_2
________________________________________________________________________________
| Subject: | Re: Proper SWR meter |
| From: | Dj Merrill <deej(at)deej.net> |
On 04/22/2010 04:25 PM, Mike Welch wrote:
> Should I not risk screwing up my Icom, and try to find a more
> appropriate SWR meter?
I do not know anything about that particular SWR meter, so I can't say
for sure. If you can find an SWR meter that covers the amateur radio
144Mhz band, that would probably be close enough so that you can tune
your antenna. Any local amateur radio operators in your area? I'm sure
they'd come out and help you for free just to see a cool project like an
airplane being built. :-)
Try looking here:
http://www.qrz.com/db/?cmd=1
and then look up their name in the phone book and give them a call.
-Dj
--
Dj Merrill - N1JOV
Glastar Sportsman 2+2 Builder #7118 N421DJ - http://deej.net/sportsman/
Grumman Yankee Driver N9870L - http://deej.net/yankee/
________________________________________________________________________________
| From: | Mike Welch <mdnanwelch7(at)hotmail.com> |
| Subject: | Proper SWR meter |
>Any local amateur radio operators in your area? I'm sure
> they'd come out and help you for free just to see a cool project like an
> airplane being built. :-)
> -Dj
DJ=2C
Re: ham radio operators=2C yes. That's where I got this SWR meter from.
Like I said in my original email=2C the instruction manual only refers to
"amateur radios".
Sounds to me as though I should be okay. I'll get the adapter from Radio
Shack tomorrow=2C and give it a try.
Mike Welch
GlaStar and MkIIIX builder
_________________________________________________________________
Hotmail has tools for the New Busy. Search=2C chat and e-mail from your inb
ox.
http://www.windowslive.com/campaign/thenewbusy?ocid=PID28326::T:WLMTAGL:O
N:WL:en-US:WM_HMP:042010_1
________________________________________________________________________________
| From: | "The Kuffels" <kuffel(at)cyberport.net> |
| Subject: | Re: Proper SWR meter |
Mike,
<< SWR meter is a Lafayette, stock no. 99-25835. .. the "right
frequency meter >>
Lafayette isn't known for excellence in design. There are two problems
with the meter you mention. First it is specified for use only up to
about 30 MHz, one fourth the frequency of the aviation communication
band around 120 MHz. As DJ mentions, it might be able to determine a
minimum bad. But personally, I wouldn't trust it. And for sure it
wouldn't tell you about the performance of your antenna near the band
edges, which is just as important as the "minimum" frequency.
Second, to work you must *transmit* power on the frequencies of
interest, a practice frowned upon by the FAA and the FCC unless you are
communicating with someone. Current practice says to use an input noise
bridge antenna analyzer such as sold by MFJ. Contact your local ham
radio club. They will probably have one as part of the club's
equipment. Even if not, for sure one of their members will have one and
be delighted to come over and help you tune/analyze your setup.
To find your local ham club log on to arrl.org. In the upper right hand
corner is a website search box. Select the Category "Clubs" and press
Go. This takes you to a clubs page. On the left side enter your Zip
code, select the desired mileage range next to it and press Search at
the bottom of this grey box. Or fly up to Whitefish Montana and I'll be
happy to help you.
Tom Kuffel, AL7AU
________________________________________________________________________________
| Subject: | Re: Alternator field feed - fuse vs. fusible link |
| From: | "Noah" <sgninc(at)cox.net> |
Great response Bob, thank you. That certainly drives the point home!
--------
Highest Regards,
Noah Forden
RV-7A
Rhode Island
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=295325#295325
________________________________________________________________________________
| From: | Mike Welch <mdnanwelch7(at)hotmail.com> |
| Subject: | RE: Proper SWR meter |
Tom=2C
Thanks for the tips. I'll see if I can find a local ham operator guy to
help get me squared away.
If I came up to Whitefish=2C MT=2C I wouldn't have time to deal with the
antenna....with my fishin' taking up all my time. :-)
Thanks again=2C Mike Welch
_________________________________________________________________
The New Busy think 9 to 5 is a cute idea. Combine multiple calendars with H
otmail.
http://www.windowslive.com/campaign/thenewbusy?tile=multicalendar&ocid=
PID28326::T:WLMTAGL:ON:WL:en-US:WM_HMP:042010_5
________________________________________________________________________________
| From: | "Dave" <dave(at)coltnet.net> |
| Subject: | KNS 80 Installation Manual |
My friend/mechanic (not on the list) is installing a kns 80 and needs
the installation manual. I found the connector pinout on Bob's Website,
But he would like to see the complete installation manual. Does anyone
has access to an installation manual ?
Thanks
Dave
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <nuckolls.bob(at)aeroelectric.com> |
| Subject: | Re: Battery chargers. |
At 06:35 PM 4/19/2010, you wrote:
>Read this link an tell me your
>comments. News to me.
>
>
>http://www.optimabatteries.com/product_support/resuscitating_agmbattery.php
"Resuscitation" is not a narrowly defined operation.
When an RG battery is so severely discharged that
its open circuit voltage is too low to tell a smart
charger to wake up, its a common practice to add an
extra boost from either another battery or perhaps
some form of bench supply.
When Concorde gets a "dead" one back, they'll do
a recovery experiment that starts with hooking a
12v battery to a 20 or more volt power supply until
the chemistry is stirred up enough for the discharged
battery to start taking in energy. After the recovery
current rises sufficiently, the charge can be completed
with more conventional protocols.
They'll charge, discharge and recharge several times
while doing a cap-check during each discharge. If after
3 cycles, the cap-check does not show sufficient capacity
for return to service (typically 80% of nameplate) the
critter was scrapped.
Some would recover, some would not depending on how long
they were held in a discharged state, at what temperature
and what the age of the battery was. But aside from the
extra-voltage jum-start, no special techniques were used.
So when someone claims to have resurrected a dead battery,
it's not clear exactly to what degree the battery has
become useful. Without comparative cap-checks, there's
no quantitative basis for claiming ressurection.
Bob . . .
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <nuckolls.bob(at)aeroelectric.com> |
| Subject: | Re: Proper SWR meter |
At 04:59 PM 4/22/2010, you wrote:
>Mike,
>
><< SWR meter is a Lafayette, stock no. 99-25835. .. the "right
>frequency meter >>
>
>Lafayette isn't known for excellence in design. There are two
>problems with the meter you mention. First it is specified for use
>only up to about 30 MHz, one fourth the frequency of the aviation
>communication band around 120 MHz. As DJ mentions, it might be able
>to determine a minimum bad. But personally, I wouldn't trust
>it. And for sure it wouldn't tell you about the performance of your
>antenna near the band edges, which is just as important as the
>"minimum" frequency.
Agreed. I blew away a lot of $time$ building matching
harnesses "checked" with a similar transmission line
reflectometer of this genre . . .
Emacs!
Optimized for the 3-30 Mhz range, these critters become
VERY accommodating and tended to show that EVERYTHING you
attached to it at 145 Mhz had a good SWR!
> Second, to work you must *transmit* power on the frequencies of
> interest, a practice frowned upon by the FAA and the FCC unless you
> are communicating with someone. Current practice says to use an
> input noise bridge antenna analyzer such as sold by MFJ. Contact
> your local ham radio club. They will probably have one as part of
> the club's equipment. Even if not, for sure one of their members
> will have one and be delighted to come over and help you
> tune/analyze your setup.
Actually, the MFJ259 is an active emitter too but in
the milliwatt level. But the best part is that it's
ability to accurately display antenna and transmission
line characteristics is quite good at 130 Mhz.
I use to rent one to the OBAM aviation community but
wear and tear outgo was higher than rental income.
Bob . . .
________________________________________________________________________________
| Subject: | Re: Alternator field feed - fuse vs. fusible link |
| From: | "rckol" <rckol(at)kaehlers.com> |
Just to play the Devil's advocate:
The breaker is part of an overvoltage protection circuit, not a conventional B
lead breaker prone to nuisance popping. Why would anyone be resetting this breaker
in flight after what is most likely an overvoltage event?
--------
rck
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=295354#295354
________________________________________________________________________________
| From: | "The Kuffels" <kuffel(at)cyberport.net> |
| Subject: | Re: Proper SWR meter |
Me:
<< you must *transmit* power on the frequencies of interest, a practice
frowned upon by the FAA and the FCC unless you are communicating with
someone. >>
Bob:
<< Actually, the MFJ259 is an active emitter too but in the milliwatt
level. >>
Absolutely true, but in this context all receivers are "active
emitters". For example, Canadian police use a special receiver to
detect the miniscule signal emitted by radar detectors to enforce their
ban on such devices. The point being made is the amount of power needed
to operate the old style SWR meters *will* cause appreciable
interference to other users while the MFJ259 and such for all practical
purposes will not.
Tom Kuffel
________________________________________________________________________________
| Subject: | Re: Surface temperature sensor |
| From: | Steve Thomas <lists(at)stevet.net> |
Why off-list? I'm sure that many readers of the list would be interested. Please
share with all of us!
Steve Thomas
________________________________________________________________________
On Apr 22, 2010, at 1:19 PM, J. Mcculley wrote:
>
> I've been using a very inexpensive system with 18 sensor locations in my Wittman
Tailwind for well over 500 hours and 7 years, with never a malfunction. It's
based on inexpensive thermistors available from most electronics suppliers
and feeds into the display head of an ordinary digital meat thermometer mounted
on my instrument panel. It can handle up to 300 degree F which covers everything
firewall-forward except engine cylinder EGT and CHT.
>
> If you want some part numbers and more details contact me off list at mcculleyja(at)starpower.net.
>
> Jim McCulley
> ===================================================================================
>
> longg(at)pjm.com wrote:
>> Q,
>> Has anyone come across an example of a surface temperature sensor (generic))
that could be used on engine parts or perhaps the firewall and send a digital
reading back to the panel?
>> Example. I would like to measure the temperature on the surface of my oil filter/fuel
pump and display that value on the panel.
>> FYI I have stick-on thermometers that work great when performing engine checks
on the ground but they are of little use in the air.
>> Thanks,
>> Glenn
>> * *
>
>
>
>
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <nuckolls.bob(at)aeroelectric.com> |
| Subject: | Re: Proper SWR meter |
At 11:46 PM 4/22/2010, you wrote:
>Me:
>
><< you must *transmit* power on the frequencies of interest, a
>practice frowned upon by the FAA and the FCC unless you are
>communicating with someone. >>
>
>Bob:
>
><< Actually, the MFJ259 is an active emitter too but in the
>milliwatt level. >>
>
>Absolutely true, but in this context all receivers are "active
>emitters". For example, Canadian police use a special receiver to
>detect the miniscule signal emitted by radar detectors to enforce
>their ban on such devices. The point being made is the amount of
>power needed to operate the old style SWR meters *will* cause
>appreciable interference to other users while the MFJ259 and such
>for all practical purposes will not.
Sure, but that wasn't the point, the MFJ device one is
looking for is not the "noise bridge antenna analyzer"
or MFJ202. This network analyzer excited by a broadband
noise source requires a receiver with a signal strength
indicator tuned to the frequency of interest as part of
the test equipment. Further their only noise bridge offering
http://mfjenterprises.com/man/pdf/MFJ-202B.pdf
is more of a system designer's instrument than
a technicians test tool.
Bob . . .
________________________________________________________________________________
| From: | "earl_schroeder(at)juno.com" <earl_schroeder(at)juno.com> |
| Subject: | Re: Proper SWR meter |
Bob wrote:
Actually, the MFJ259 is an active emitter too but in
the milliwatt level. But the best part is that it's
ability to accurately display antenna and transmission
line characteristics is quite good at 130 Mhz.
I use to rent one to the OBAM aviation community but
wear and tear outgo was higher than rental income.
Bob . . .
When you 'rented' the MFJ259, did you include a simplified instruction sheet?
As a proud owner of a MFJ259, I would like a 'cook book' type instructions tailored
to the OBAM aviation community.
I would like to know all the theory etc but at this time do not have the time to
invest in learning its complete capability and retaining it. I am interested
but short on time. My Grandson currently has priority!
I just want to know how to correctly connect it and read the SWR. Then some clues
as to how to correct it if necessary.
Then I would like to assist my EAA chapter folks in checking their installations.
The MFJ259 sitting on the shelf isn't doing anyone an favors... (no, it isn't
for sale at this time) Earl
________________________________________________________________________________
| From: | "Ken Howell" <cfi1513840(at)gmail.com> |
| Subject: | Future of general aviation |
I agree with everything you said. There is one other factor to consider,
affordability. It may have already been discussed. As an E3 in 1957, I could
actually afford to take flying lessons. As a 25 year-old raising a family, I
could afford to own and fly a Porterfield CP-65. Now with the cost of
litigation and fuel, that is no longer the case for the majority of young
people. Even with the new LSA rules, it's out of the reach of most. The
lawyers have successfully killed the prospects of a continuing, vital
General Aviation system in America, witness the recent 89 million dollar
award against Lycoming, who are being made to pay for pilot error. The oil
companies are contributing to its demise with their exhorbitant rates,
insuring their continuing record profits each quarter. I'm still a
capitalist and not overly pessimistic, but I have to say even though it was
great while it lasted; RIP to GA in America.
-----Original Message-----
From: owner-aeroelectric-list-server(at)matronics.com
[mailto:owner-aeroelectric-list-server(at)matronics.com] On Behalf Of Robert L.
Nuckolls, III
Sent: Thursday, April 22, 2010 10:51 AM
Subject: Re: AeroElectric-List: Future of general aviation
-->
>We all need to contribute to the continuance of this legacy by
>supporting programs like Young Eagles, encouraging youth who express
>interest in what we do, participating in information exchange forums
>like this one, and never taking the privilege of flying for granted.
I fear that the inoculation for indifference may be more
complicated that enthusiastic offers of airplane rides.
Our culture is slowly loosing its curiosity and excitement
as to how and why things work. There's more interest in
stepping up to the next revision of "Borg Wars" or
seeking out the most outrageous roller coaster. The
perpetual quest for transient pleasures is winning out
over the joy of finding things out.
Young Eagles is a fine idea but it's also a "process"
enthusiastically endorsed by folks who think education
is "flip switch A, insert tab C into slot D, watch
video F, etc".
Real teaching is a meeting of the minds, an exchange
of concepts and a study of recipes for success crafted
of simple-ideas.
My grandson doesn't know what he's in for. We're going
to cook, grow, build, design, cut metal, photoshop,
autocad, cut wood, take things apart, put them back
together and explore the simple-ideas that are discovered
in the process. Exactly how he uses these experiences
will ultimately be up to him. But without having peeked
behind all those doors, how can he make well considered
choices?
Our contemporaries have, I suspect, not peeked behind
many doors . . . their teachers (which includes EVERY
adult interaction in their younger lives) have failed
them. I have the signatures of more than 50 young eagles
in my logbook . . . I'll bet not one of them has set
foot back in an airplane . . . unless it was at the
NEXT air show where free rides were offered again.
That "privilege" thing is closely related to what
doors have been peeked into. Present trends plotted
into the future suggest that ANY privilege we now
enjoy can disappear any time with the mere stroke
of a pen in Washington.
Bob . . .
________________________________________________________________________________
| From: | "The Kuffels" <kuffel(at)cyberport.net> |
| Subject: | Re: Proper SWR meter |
<< Sure, but that wasn't the point, the MFJ device one is
looking for is not the "noise bridge antenna analyzer"
or MFJ202 >>
As usual, Bob is correct. I falsely "remembered" my MFJ HF/VHF SWR
Analyzer Model MFJ-259B used noise bridge technology. Should have
checked my instruction manual first and used the full, official name.
The Model MFJ-259 Analyzer is what you will commonly find available from
local ham radio operators/clubs. The original point remains, it is a
much better tool to adjust aircraft antennas than the Lafayette style
SWR meters.
Tom Kuffel
________________________________________________________________________________
| Subject: | Re: Surface temperature sensor |
| From: | "rampil" <ira.rampil(at)gmail.com> |
Don't count on home and garden type thermometer systems to be
especially accurate. They have no requirement to be calibrated
or calibrateable.
--------
Ira N224XS
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=295453#295453
________________________________________________________________________________
| Subject: | Re: Surface temperature sensor |
| From: | Dj Merrill <deej(at)deej.net> |
On 4/23/2010 4:45 PM, rampil wrote:
>
> Don't count on home and garden type thermometer systems to be
> especially accurate. They have no requirement to be calibrated
> or calibrateable.
Easy enough to test - put the sensor in boiling water. If it is even
remotely close to the right value, it is probably "good enough" for most
of our purposes. Hard to argue with the price... :-)
-Dj
--
Dj Merrill - N1JOV
Glastar Sportsman 2+2 Builder #7118 N421DJ - http://deej.net/sportsman/
Grumman Yankee Driver N9870L - http://deej.net/yankee/
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <nuckolls.bob(at)aeroelectric.com> |
| Subject: | Re: Alternator field feed - fuse vs. fusible |
link
At 09:48 PM 4/22/2010, you wrote:
>
>Just to play the Devil's advocate:
>
>The breaker is part of an overvoltage protection circuit, not a
>conventional B lead breaker prone to nuisance popping. Why would
>anyone be resetting this breaker in flight after what is most likely
>an overvoltage event?
While we do our best to fine tune the dynamic
response of all over-voltage protection systems,
the designs are based on 99% probability dynamics.
I.e., tailor your circuitry to these curves . . .
http://www.aeroelectric.com/Reference_Docs/Mil-Specs/Mil-Std-704_excerpts.pdf
. . . and you're good to go . . . MOST of the time.
In 40+ years of designing and manufacturing various
ov sensing systems, there have been a few instances where
antagonists on the particular system were more aggressive
that the 99% curves suggested. Hence, virtually every
ov protection system has a pilot-resetable feature.
Of course, like any breaker-trip, the most you want to
tweak the tail of the tiger is one time before leaving
it off and go to plan-B.
Bob . . .
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <nuckolls.bob(at)aeroelectric.com> |
| Subject: | Re: Proper SWR meter |
At 11:37 AM 4/23/2010, you wrote:
><< Sure, but that wasn't the point, the MFJ device one is
> looking for is not the "noise bridge antenna analyzer"
> or MFJ202 >>
>
>As usual, Bob is correct. I falsely "remembered" my MFJ HF/VHF SWR
>Analyzer Model MFJ-259B used noise bridge technology. Should have
>checked my instruction manual first and used the full, official
>name. The Model MFJ-259 Analyzer is what you will commonly find
>available from local ham radio operators/clubs. The original point
>remains, it is a much better tool to adjust aircraft antennas than
>the Lafayette style SWR meters.
ABSOLUTELY!! I've owned three of them
and it's the first tool I pick up when there
are questions of feed line and/or antenna
quality to be explored.
I used to have a noise-bridge. It does perform
as advertised and was VERY reasonably priced because
the heavy lifting for test equipment was the companion
receiver not supplied. I think I gave that one away
many moons ago.
Bob . . .
________________________________________________________________________________
| From: | "J. Mcculley" <mcculleyja(at)starpower.net> |
| Subject: | Re: Surface temperature sensor |
Sorry Steve and others...I just thought this subject might be of
interest to so few that I should not take up bandwith that those not
interested would have to deal with. But, here it is:
This is a very accurate system that I tested with a laboratory quality
temperature meter and found the accuracy of all my sensors to be two
degrees F. It may not be very sophisticated, but it is super-inexpensive
and has never malfunctioned. I use it on every flight to assure myself
that no changes suddenly occur that could indicate a malfunction.
Mine is about a $15 to $25 system that I've operated now for over seven
years and upwards of 600 flight hours on it's original internal
watch-size battery. The sensors are standard mini glass-encapsulated
thermistors available from most electronic supply sources. I used
Digi-Key # KC013-ND, 100k ohm units.
For those sensors measuring metal surface temperatures (cylinder bases,
starter, mags, boost pump, alternator, etc.) the sensors are attached to
the surfaces with heat sink grease, and held in place mechanically
and/or with a coating of the red 600 degree RTV, then insulated from
surrounding radiation with fireman's suit material. To assure firm
contact with the surface until the RTV sets requires some simple tricks
I wont cover unless you desire later.
Those sensors that measure airflow temperatures are mechanically
supported in various ways depending upon the surrounding environment,
and are then shielded from nearby heat radiation, using standoff shields.
The display is a panel mounted single LCD with a compact surface mount
IC unit that I adapted from a meat thermometer with a range up to 300F.
The head of the meat thermometer becomes the panel mounted digital
display after cutting off the long stem, but retaining the internal pair
of wires to the display head.
The individual sensor locations are selected for readout through a
rotary switch on the panel. The delay in the presentation from one
sensor selection to the next is less than one second and my poor-man's
data recording system is via my hot mike through the intercom to a voice
recorder. In this current era of exotic digital commercial boxes for
anything a person desires, my "keep-it-simple and build-in-lightness
mentality" may not be the answer for others, but I don't mind
post-flight manually inputting the data from my recorder into a
spreadsheet for further massaging if needed.
The installation of the thermistors is simpler and much less expensive
than thermocouples and since the thermistors operate in a very
high-impedence circuit the wiring need not be any larger size than
needed to assure mechanical robustness. I used 22 gauge wire and joined
all the ground return wires together to pass through the firewall as a
single lead, so the wire bundle becomes very small aft of the firewall.
Also, because of the very high impedence of the circuitry, there is no
sensitivity to length of individual sensor wires between thermistor and
display for any possible location within a general aviation
installation. Good quality soldering technique is very adequate for
connections, as are properly-crimped-on terminals, if desired.
=======================================================================
Steve Thomas wrote:
>
> Why off-list? I'm sure that many readers of the list would be interested.
> Please share with all of us!
>
>
> Steve Thomas
> ________________________________________________________________________
>
>
>
>
> On Apr 22, 2010, at 1:19 PM, J. Mcculley wrote:
>
>> I've been using a very inexpensive system with 18 sensor locations in my
>> Wittman Tailwind for well over 500 hours and 7 years, with never a
>> malfunction. It's based on inexpensive thermistors available from most
>> electronics suppliers and feeds into the display head of an ordinary
>> digital meat thermometer mounted on my instrument panel. It can handle
>> up to 300 degree F which covers everything firewall-forward except engine
>> cylinder EGT and CHT.
>>
>> If you want some part numbers and more details contact me off list at
>> mcculleyja(at)starpower.net.
>>
>> Jim McCulley
>> =========================================================================
>>
>> longg(at)pjm.com wrote:
>>> Q,
>>> Has anyone come across an example of a surface temperature sensor (generic))
>>> that could be used on engine parts or perhaps the firewall and send
a digital
>>> reading back to the panel?
>>> Example. I would like to measure the temperature on the surface of my
>>> oil filter/fuel pump and display that value on the panel.
>>> FYI I have stick-on thermometers that work great when performing
>>> engine checks on the ground but they are of little use in the air.
>>> Thanks,
>>> Glenn
>>> * *
>
>
>
>
>
>
________________________________________________________________________________
| Subject: | Big load on BAT BUS |
| From: | "jonlaury" <jonlaury(at)impulse.net> |
In an attempt to keep redundant critical items from the same bus, I have placed
the fuse (10-15 amp) for my EFI injectors on the Bat Bus.
However, this violates BoB N's limit of
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=295529#295529
________________________________________________________________________________
| Subject: | Re: Big load on BAT BUS |
| From: | "jonlaury" <jonlaury(at)impulse.net> |
Never mind about the SS sleeve question. It will only be a 10 gauge wire and I
will 18 ga fuselink it at the battery.
J
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=295530#295530
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <nuckolls.bob(at)aeroelectric.com> |
| Subject: | Re: Big load on BAT BUS |
At 01:31 AM 4/24/2010, you wrote:
>
>In an attempt to keep redundant critical items from the same bus, I
>have placed the fuse (10-15 amp) for my EFI injectors on the Bat Bus.
>However, this violates BoB N's limit of
Then you need a "mini-contactor" at the battery
bus as illustrated in Z-32, except that the
feeder is for the EFI instead of the E-bus.
It would be nice if it were a solid state
relay. I believe Eric Jones still offers
on.
Bob . . .
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <nuckolls.bob(at)aeroelectric.com> |
| Subject: | Re: Big load on BAT BUS |
At 01:38 AM 4/24/2010, you wrote:
>
>Never mind about the SS sleeve question. It will only be a 10 gauge
>wire and I will 18 ga fuselink it at the battery.
This sounds like another "loose cannon"
implementation of fusible links. Fusible
links are ROBUST circuit protection and should
never be used in an always-hot feeder from
a battery. If you've attached a wire to
a battery that calls for this kind of circuit
protection, it should enjoy upstream, crew-
controlled management of power.
As a general rule, please do not add fusible
links to any application not already illustrated
in the Z-figures without discussing it here
on the List . . . and I can tell you in advance
there's a 90+ percent chance that the proposed
application is not recommended.
Always-hot feeders should be breakered at
5A or less, fused at 7A or less. Anything
larger should still take a fuse or breaker
but CONTROLLED IMMEDIATELY ADJACENT to
the bus with a relay like that shown in Z-32.
Bob . . .
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <nuckolls.bob(at)aeroelectric.com> |
| Subject: | Re: Surface temperature sensor |
At 09:38 PM 4/23/2010, you wrote:
>Mcculley"
>
>Sorry Steve and others...I just thought this subject might be of
>interest to so few that I should not take up
>bandwith that those not interested would have to deal with. But, here it is:
>
>
>This is a very accurate system that I tested with a laboratory quality
>temperature meter and found the accuracy of all my sensors to be two
>degrees F. It may not be very sophisticated, but it is super-inexpensive
>and has never malfunctioned. I use it on every flight to assure myself
>that no changes suddenly occur that could indicate a malfunction.
>
>Mine is about a $15 to $25 system that I've operated now for over seven
>years and upwards of 600 flight hours on it's original internal
>watch-size battery. The sensors are standard mini glass-encapsulated
>thermistors available from most electronic supply sources. I used
>Digi-Key # KC013-ND, 100k ohm units.
How was it that you determined that the 100K devices were
appropriate to your particular display? Folks should understand
that there are hundreds of remote temperature measurement
products on the market. I've see them use thermocouples, solid
state LINEAR temperature sensors, diodes, the junctions of
transistors (also a diode) AND thermistors.
http://www.gesensing.com/products/resources/datasheets/ge1.pdf
Thermistors are inexpensive AND rugged but they have the
distinct disadvantage of being non-linear. So the accurate
temperature display not only needs to know what the resistance
of the device is at say 25C, the designer will compensate for
the shape of temperature/resistance curve as well.
The first thing one needs to do when adapting a commercial
off the shelf (COTS) indicator to their airplane is to determine
the sensor technology. If a thermistor, then you need to get
the 25C resistance rating, and then the resistance at some
other handy value (boiling water - 100C) and then find
substitute sensors of identical characteristics.
The really cool thing about the linear, solid state sensors
is that they are direct reading, linear, and of known accuracy
out of the box. I'm not discouraging anyone from exploring
adaptation of any COTS temperature display but understand that
there are some inviolate rules by which the sensing technology
is identified and then duplicated so that the display performs
as expected.
Bob . . .
________________________________________________________________________________
| From: | Ken <klehman(at)albedo.net> |
| Subject: | Re: Big load on BAT BUS |
There are details that aren't mentioned but I would be cautious with
this. I'd only recommend an additional mini contactor if it is truly
redundant and can't fail the engine. Risk from engine stoppage is likely
far higher than the risk from electrical fire. Other considerations
might be whether the EFI system already has a relay to supply injector
power - many do have an ecu controlled relay that might be easily placed
near the battery. Or is there a mechanical switch in the injector
circuit - there is in my system and it is close to the battery which is
under the instrument panel. The 10 amp fuse is at the battery.
Ideally a redundant engine control system would be powered by its own
power source with no shared wiring.
To understand where I am coming from, understand that the so called
"redundant" electronic engine systems that I've examined do not come
close to true redundancy. Most do not have dual injectors and most share
a single feed to the injectors.
Ken
Robert L. Nuckolls, III wrote:
>
>
> At 01:31 AM 4/24/2010, you wrote:
>>
>>
>> In an attempt to keep redundant critical items from the same bus, I
>> have placed the fuse (10-15 amp) for my EFI injectors on the Bat Bus.
>> However, this violates BoB N's limit of
>
> Then you need a "mini-contactor" at the battery
> bus as illustrated in Z-32, except that the
> feeder is for the EFI instead of the E-bus.
>
> It would be nice if it were a solid state
> relay. I believe Eric Jones still offers
> on.
>
> Bob . . .
>
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <nuckolls.bob(at)aeroelectric.com> |
| Subject: | Re: Proper SWR meter |
>When you 'rented' the MFJ259, did you include a simplified instruction sheet?
>
>As a proud owner of a MFJ259, I would like a 'cook book' type
>instructions tailored to the OBAM aviation community.
>
>I would like to know all the theory etc but at this time do not have
>the time to invest in learning its complete capability and retaining
>it. I am interested but short on time. My Grandson currently has priority!
>
>I just want to know how to correctly connect it and read the
>SWR. Then some clues as to how to correct it if necessary.
As a matter of fact, I think I did but it's
on the computer in M.L.
I'll see if I can did it up and post it early
next week. If not, I'll write up a new one.
It's pretty straight forward . . . perhaps
a cognizant user of such devices will come
up with a procedure before I get to it.
Bob . . .
________________________________________________________________________________
| Subject: | Re: Big load on BAT BUS |
| From: | "jonlaury" <jonlaury(at)impulse.net> |
nuckolls.bob(at)aeroelect wrote:
> At 01:38 AM 4/24/2010, you wrote:
>
> >
> >
> > Never mind about the SS sleeve question. It will only be a 10 gauge
> > wire and I will 18 ga fuselink it at the battery.
> >
> >
>
> This sounds like another "loose cannon"
> implementation of fusible links.
> Bob . . .
Admittedly, it is. And that is why I "disclosed" what I was going to do. It seemed
like a good idea. The feedback here is invaluable as is an occasional slap
upside the head :-)
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=295553#295553
________________________________________________________________________________
| From: | "J. Mcculley" <mcculleyja(at)starpower.net> |
| Subject: | Re: Surface temperature sensor |
Using a laboratory quality temperature instrument I determined the
readings (at about 10 degree F intervals) of a typical digital display
meat thermometer (10-15 dollar variety some 10 years ago) and found the
error varied well within +/- 3F within the range of interest I
considered appropriate as about 70 to 300F for firewall-forward
applications.
Then by carefully extracting the sensor inside the very tip of the meat
thermometer, I compared it in size and appearance to a variety of
commercially available thermistors and tested several by electrically
substituting them in place of the original until finding the one I
mentioned by source and part number to be apparently identical in
performance over the same range of temperature interest.
After completing the installation in the aircraft, another test with the
lab-quality meter for comparison gave the same ballpark results and also
showed that with the nominal 100K resistance value stated for the
thermistor, the total impedance of the completed installation for any
likely difference in length of wiring between the closest versus
greatest distance of sensors created no error even when wired with the
smallest gauge wire I felt appropriate for use in an aircraft
installation with heat and vibration considerations.
My assumption was/is that the surface mounted electronic circuitry in
the meat thermometer display head performs the necessary compensation
for non linear characteristics of the basic thermistor. Although I was
unable to obtain any data from the thermometer vendor, I assume I was
just lucky enough to perhaps have stumbled upon the exact same-source
thermistor used in the retail unit.
Jim McCulley
========================================================================================
Robert L. Nuckolls, III wrote:
>
>
> At 09:38 PM 4/23/2010, you wrote:
>>
>>
>> Sorry Steve and others...I just thought this subject might be of
>> interest to so few that I should not take up bandwith that those not
>> interested would have to deal with. But, here it is:
>>
>>
>> This is a very accurate system that I tested with a laboratory quality
>> temperature meter and found the accuracy of all my sensors to be two
>> degrees F. It may not be very sophisticated, but it is super-inexpensive
>> and has never malfunctioned. I use it on every flight to assure myself
>> that no changes suddenly occur that could indicate a malfunction.
>>
>> Mine is about a $15 to $25 system that I've operated now for over seven
>> years and upwards of 600 flight hours on it's original internal
>> watch-size battery. The sensors are standard mini glass-encapsulated
>> thermistors available from most electronic supply sources. I used
>> Digi-Key # KC013-ND, 100k ohm units.
>
> How was it that you determined that the 100K devices were
> appropriate to your particular display? Folks should understand
> that there are hundreds of remote temperature measurement
> products on the market. I've see them use thermocouples, solid
> state LINEAR temperature sensors, diodes, the junctions of
> transistors (also a diode) AND thermistors.
>
> http://www.gesensing.com/products/resources/datasheets/ge1.pdf
>
> Thermistors are inexpensive AND rugged but they have the
> distinct disadvantage of being non-linear. So the accurate
> temperature display not only needs to know what the resistance
> of the device is at say 25C, the designer will compensate for
> the shape of temperature/resistance curve as well.
>
> The first thing one needs to do when adapting a commercial
> off the shelf (COTS) indicator to their airplane is to determine
> the sensor technology. If a thermistor, then you need to get
> the 25C resistance rating, and then the resistance at some
> other handy value (boiling water - 100C) and then find
> substitute sensors of identical characteristics.
>
> The really cool thing about the linear, solid state sensors
> is that they are direct reading, linear, and of known accuracy
> out of the box. I'm not discouraging anyone from exploring
> adaptation of any COTS temperature display but understand that
> there are some inviolate rules by which the sensing technology
> is identified and then duplicated so that the display performs
> as expected.
>
> Bob . . .
>
>
>
>
>
>
________________________________________________________________________________
| From: | "Valin & Allyson Thorn" <thorn(at)starflight.aero> |
| Subject: | Z-12 Power Grid Behavior |
Hello Bob K. and anyone else who wants to weigh in.
Could I please get confirmation that I'm interpreting the Z-12 power grid
design behavior correctly (Z-12 = Main Alt, Standby Alt, One Battery, Main
Bus, E-Bus) represented in these statements below?
. One can normally fly with E-Bus feed switch ON since an alternator
energized Main Bus is at a higher voltage than the battery and it will feed
the E-Bus thru the diode when operating. So even if both alternators fail
and battery contactor failed the E-Bus will receive battery power without
any action required from the pilot.
. If the Battery Contactor Relay is opened, isolating the battery
from the Main Bus, while either alternator is operating, the alternator will
continue to provide good power to the Main Bus and E-Bus without the battery
in the circuit.
Are these interpretations correct?
In the bullet two scenario where the engine is running, an alternator is
making power, and the battery contactor relay is open, will there be any
power quality or stability issues with the electrical system without the
battery in the circuit?
Thanks,
Valin
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <nuckolls.bob(at)aeroelectric.com> |
| Subject: | Re: Surface temperature sensor |
>Then by carefully extracting the sensor inside the very tip of the
>meat thermometer, I compared it in size and appearance to a variety
>of commercially available thermistors and tested several by
>electrically substituting them in place of the original until
>finding the one I mentioned by source and part number to be
>apparently identical in performance over the same range of
>temperature interest.
Aha! Then there was a rational exercise to pick a
thermistor that matched the operating characteristics
of the device being cloned.
This is the point that we needed to make clear
to our readers. There are thousands of thermistor
parts of which only a few will directly replace the
sensor used in a randomly selected off the shelf
thermometer.
I assume I was just lucky enough to perhaps have stumbled upon the
exact same-source thermistor used in the retail unit.
Don't know about 'luck'. You can measure the 25C
resistance point for device under study. You could
also measure it's resistance at say, two other points
over the range of interest . . . like 0C (ice point)
and 100C (boiling point). Then by studying the
temperature/resistance transfer curves (or as you
did, experimentation) you can find a match. Afterr
that, you're home free. As you've described, you
can switch as many remote sensors in to the display
as you like.
The only thing I wanted to make clear was that
unlike thermocouples and factory calibrated
temperature sensors, thermistors are a breed
unto themselves. The successful user will have
to learn a few dditions to their back of
electro-whizzy tricks.
Thanks for sharing your experience in this
discussion!
Bob . . .
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <nuckolls.bob(at)aeroelectric.com> |
| Subject: | Re: Big load on BAT BUS |
> > This sounds like another "loose cannon"
> > implementation of fusible links.
> > Bob . . .
>
>
>Admittedly, it is. And that is why I "disclosed" what I was going to
>do. It seemed like a good idea. The feedback here is invaluable as
>is an occasional slap upside the head :-)
Naw, just a short "time out" in "now you
know better corner". Folks on this List
strive to be gentle but clear teachers. This
should be an experience of discovery not
of discomfort. Thanks for sharing.
Bob . . .
________________________________________________________________________________
| From: | "Harold Lanfear" <hlanfear(at)verizon.net> |
| Subject: | Nav Audio Connection |
I'm currently wiring the audio portion of my Garmin 430W into the
intercom. The company that did the harness simply labeled this wire as
"Nav Audio, for future use" When I traced the pinouts, I discovered
this wire to be the VOR / ILS Audio Hi & Lo wires. Can I connect these
to the same pins as the Com Audio without a problem?
I'm using Vern Little's AMX-2A Audio Mixer for some audio inputs from my
Grand Rapids EIS and some warning systems so I could use this for the
Nav input as well, if that would be better.
Thanks for the help in advance.
Harold Lanfear
________________________________________________________________________________
| Subject: | Re: Z-12 Power Grid Behavior |
| From: | "user9253" <fran4sew(at)banyanol.com> |
> One can normally fly with E-Bus feed switch ON
Doing so will not hurt anything.
> since an alternator energized Main Bus is at a higher voltage than the battery
and it will feed the E-Bus thru the diode when operating.
Not true. The Main Bus and battery will be at essentially at the same voltage.
The diode will NOT conduct with the E-Bus switch closed because the diode has
been shorted out by the parallel current path through the E-Bus switch.
> So even if both alternators fail and battery contactor failed the E-Bus will
receive battery power without any action required from the pilot.
That is true as long as the E-Bus switch is closed.
> the Battery Contactor Relay is opened, isolating the battery from the Main Bus,
while either alternator is operating, the alternator will continue to provide
good power to the Main Bus and E-Bus without the battery in the circuit.
Probably, but not certain. It all depends on the components used.
> will there be any power quality or stability issues with the electrical system
without the battery in the circuit?
I do not think so, but am not sure.
Joe
--------
Joe Gores
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=295621#295621
________________________________________________________________________________
| Subject: | Re: Surface temperature sensor |
| From: | "user9253" <fran4sew(at)banyanol.com> |
Jim McCulley,
Good job making an economical and accurate multi-point temperature sensor and indicator.
I admire your ingenuity and resourcefulness.
Joe
--------
Joe Gores
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=295622#295622
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <nuckolls.bob(at)aeroelectric.com> |
| Subject: | RE: Designing a circuit question |
At 04:39 PM 4/24/2010, you wrote:
> > I'm fiddling with a variant of the circuit I
> > published to convert it to a solid state breaker
> > instead of current limiter.
> > I'll see if I can publish that variant tomorro evening.
> >
> > Bob . . .
>
>Hi Bob,
>
> If you are still working on this solid state design you talked
> about, I was wondering if it would be possible to incorporate a
> feature that allows the user to set for different loads.
> In other words, a 2amp setting, a 3 amp setting, etc,
> etc..........or did you intend on this, anyway?
>
> I'm really looking forward to what you come up with. I
> definitely plan on building it!!
Thanks! There is no greater validation of
an recipe for success than multiple experiences
by multiple chefs in their own kitchens.
I suspect there are some other folks on the list
who might have some ideas about how to synthesize
all silicon circuit breaker.
Getting it to trip at the right current isn't hard.
What we need to keep in mind about thermal circuit
breakers is their I(squared)*R tripping dynamic
that gives them some degree of immunity to inrush
tripping.
In the design study before us, we're dealing with
a PM DC motor that has a significant inrush
characteristic. so what we'll want to do for THIS
case is design a 'breaker' that is also a current
limiter but with some form of trip-delay . . . say
something on the order of 200 milliseconds.
I'm mulling over several ideas for minimizing
parts count while meeting design goals. Any
electron herders out there want to swap ideas?
Bob . . .
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <nuckolls.bob(at)aeroelectric.com> |
| Subject: | Re: Nav Audio Connection |
At 07:11 AM 4/25/2010, you wrote:
>I'm currently wiring the audio portion of my Garmin 430W into the
>intercom. The company that did the harness simply labeled this wire
>as "Nav Audio, for future use" When I traced the pinouts, I
>discovered this wire to be the VOR / ILS Audio Hi & Lo wires. Can I
>connect these to the same pins as the Com Audio without a problem?
Yes. LO = ground, HI = nav audio source
>
>I'm using Vern Little's AMX-2A Audio Mixer for some audio inputs
>from my Grand Rapids EIS and some warning systems so I could use
>this for the Nav input as well, if that would be better.
Normally one would gather all audio sources together into
a single mixer . . . so yes, that would be preferre.
Bob . . .
________________________________________________________________________________
| From: | "Chris Hukill" <cjhukill(at)cox.net> |
I am wiring my RV10 with an avionics bus relay. I will activate the
relay by switching the ground. I want to power the "activate power" lead
with both the main bus and the avionics bus, as to allow a back door to
the main bus thru the avionics bus, via the alternate ebus feed in the
event of a failed master relay, in-flight. I need to know the rating and
source for the diodes on the activate power leads. The small 50amp Bosch
relay only draws .1 amp to close.
Chris Hukill
________________________________________________________________________________
| From: | "Stein Bruch" <stein(at)steinair.com> |
| Subject: | Nav Audio Connection |
Hi Harold,
Not really a good idea to hook those together as they are meant for a
separate channel on either the mixer or audio panel/intercom so you can shut
the "ident" stream off when no desired. The LOW isn't that big of a deal
(Low mostly = ground).
Cheers,
Stein
From: owner-aeroelectric-list-server(at)matronics.com
[mailto:owner-aeroelectric-list-server(at)matronics.com] On Behalf Of Harold
Lanfear
Sent: Sunday, April 25, 2010 7:12 AM
Subject: AeroElectric-List: Nav Audio Connection
I'm currently wiring the audio portion of my Garmin 430W into the intercom.
The company that did the harness simply labeled this wire as "Nav Audio, for
future use" When I traced the pinouts, I discovered this wire to be the VOR
/ ILS Audio Hi & Lo wires. Can I connect these to the same pins as the Com
Audio without a problem?
I'm using Vern Little's AMX-2A Audio Mixer for some audio inputs from my
Grand Rapids EIS and some warning systems so I could use this for the Nav
input as well, if that would be better.
Thanks for the help in advance.
Harold Lanfear
________________________________________________________________________________
| From: | "J. Mcculley" <mcculleyja(at)starpower.net> |
| Subject: | Re: Surface temperature sensor |
Thanks, Joe, for the compliment! Hope you find the concept useful for
your purposes.
Jim
============================================================================================
user9253 wrote:
>
> Jim McCulley,
> Good job making an economical and accurate multi-point temperature sensor and
indicator. I admire your ingenuity and resourcefulness.
> Joe
>
> --------
> Joe Gores
>
>
>
>
> Read this topic online here:
>
> http://forums.matronics.com/viewtopic.php?p=295622#295622
>
>
>
>
>
>
>
>
>
>
>
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <nuckolls.bob(at)aeroelectric.com> |
| Subject: | Re: diode to relay |
At 10:20 AM 4/25/2010, you wrote:
>I am wiring my RV10 with an avionics bus relay. I will activate the
>relay by switching the ground. I want to power the "activate power"
>lead with both the main bus and the avionics bus, as to allow a back
>door to the main bus thru the avionics bus, via the alternate ebus
>feed in the event of a failed master relay, in-flight. I need to
>know the rating and source for the diodes on the activate power
>leads. The small 50amp Bosch relay only draws .1 amp to close.
The coil spike suppression diodes are
the least critical application you'll need
to address. Any current rating at any voltage
you can find is electrically adequate to
the task. However, 1N400x or 1N540x series
devices are suggested as MECHANICALLY robust
and relatively easy to find. Take your pick
of these Radio Shack parts.
http://aeroelectric.com/Pictures/Misc/RS_Diodes.jpg
Bob . . .
________________________________________________________________________________
| From: | "Dennis & Anne Glaeser" <glaesers(at)wideopenwest.com> |
| Subject: | Re: Designing a circuit |
Joe Gores not only suggested using a reed switch to sense my prop end of
travel, he even gave me one to try! Today I went out and played a bit. I
found that 3 winds of 18AWG causes the switch to close just as the motor
starts to strain against the stop. So I used a dab of Goop to mate the wire
loops to the reed switch and used a piece of nylon tubing as a container.
I'm attaching a picture, but don't remember if those get through on this
list. Doing this was a lot easier than I had imagined. It work great on
the ground, but the weather here in MI was low IFR all day so no flight
testing.
I've already ordered the parts for the circuit Bob designed, so I'll be
playing with that soon as well. I'll be able to have both methods operating
in parallel.
Thanks guys!
Dennis
________________________________________________________________________________
| Subject: | Re: diode to relay |
| From: | "user9253" <fran4sew(at)banyanol.com> |
If I understand correctly, you want the option of being able to power the main
bus through the avionics bus alternate feed. The avionics bus circuit would have
to be able to handle the current requirements of both the Main and avionics
bus circuits. If the avionics bus switch were inadvertently left on during
engine start, part of the starting current would go through the avionics bus circuit,
possibly overloading it.
Your plan is doable, as long as you are aware of the limitations.
Other options to accomplish your goal include using two master contactors in parallel
or using a relay in parallel with the master contactor.
Joe
--------
Joe Gores
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=295731#295731
________________________________________________________________________________
| From: | Kenneth Johnson <kjohnsondds(at)yahoo.com> |
Aircraft Electrical Gurus,=0AThis subject has been presented briefly recent
ly, but I was looking for the opinion of several.- This may-have an ele
ctrical solution of not.- The question is: "What is the best way to stop
your aircraft engine?=0A=0AIn the recent past, at this site I have seen rec
ommended a switch to the fuel pump.- Turn off the fuel pump and eventuall
y the engine stops.- =0A=0AI rent Cessna 172 and the prefered way to stop
the engine is to minimize both the throttle and richness knobs by pulling
them out.- Technically, what exactly does this do?- Could I place a sim
ple ball valve on my fuel rail and phsically close it?- Is this what I do
on the Cessna 172?- The Cessna fuel is fed throught a carburetor and my
engine is fuel injected.- Does that make a difference?=0A=0AOn the automo
bile engine, when we turn off the engine, are we just closing the switch th
at provides current to the spark plugs, or is something else involved?-
- Is this what should be done for the aircraft engine?=0A=0AThanks for yo
ur advice.=0A=0AKen Johnson=0A=0A=0A=0A
________________________________________________________________________________
| From: | Ron Quillin <rjquillin(at)cox.net> |
| Subject: | Re: Designing a circuit |
At 17:55 4/25/2010, you wrote:
>Joe Gores not only suggested using a reed switch to sense my prop
>end of travel, he even gave me one to try! Today I went out and
>played a bit. I found that 3 winds of 18AWG causes the switch to
>close just as the motor starts to strain against the stop. So I
>used a dab of Goop to mate the wire loops to the reed switch and
>used a piece of nylon tubing as a container. I'm attaching a
>picture, but don't remember if those get through on this
>list. Doing this was a lot easier than I had imagined. It work
>great on the ground, but the weather here in MI was low IFR all day
>so no flight testing.
>
>I've already ordered the parts for the circuit Bob designed, so I'll
>be playing with that soon as well. I'll be able to have both
>methods operating in parallel.
>
> Thanks guys!
> Dennis
Not sure if this is required or not, but a word of caution from one
who's been there.
I've found, by experience, the glass envelope of reed relays can be
fragile and is susceptible to fracture by external forces on the end
leads. As we don't know how yours' is to be secured, just use care
to insure no side loads can transfer from the crimped terminals to
the interface of the lead and the glass.
For me, successful designs have always securely mounted the relay on
a board or terminal strip, and had all wires exit from strain
relieved terminals; preventing any loads to the reed relay itself.
Best---
Ron Q.
________________________________________________________________________________
| From: | "Bruce Gray" <bgray(at)glasair.org> |
In an Aviation carb=92ed or injected engine, the shutoff method is the
same- turn off the fuel. The reason for this is to prevent a fuel/air
mixture being left in a cylinder. If a P lead wire is broken and the
propeller is turned, it could fire and injure someone. From your
question I assume you=92re installing an auto engine.
Auto engines kill the spark. Some might also kill the pressure in the
fuel rail. You=92re going to have to blas=E9 your own trail here.
Bruce
www.Glasair.org
-----Original Message-----
From: owner-aeroelectric-list-server(at)matronics.com
[mailto:owner-aeroelectric-list-server(at)matronics.com] On Behalf Of
Kenneth Johnson
Sent: Tuesday, April 27, 2010 12:45 PM
Subject: AeroElectric-List: stopping engine
Aircraft Electrical Gurus,
This subject has been presented briefly recently, but I was looking for
the opinion of several. This may have an electrical solution of not.
The question is: "What is the best way to stop your aircraft engine?
In the recent past, at this site I have seen recommended a switch to the
fuel pump. Turn off the fuel pump and eventually the engine stops.
I rent Cessna 172 and the prefered way to stop the engine is to minimize
both the throttle and richness knobs by pulling them out. Technically,
what exactly does this do? Could I place a simple ball valve on my fuel
rail and phsically close it? Is this what I do on the Cessna 172? The
Cessna fuel is fed throught a carburetor and my engine is fuel injected.
Does that make a difference?
On the automobile engine, when we turn off the engine, are we just
closing the switch that provides current to the spark plugs, or is
something else involved? Is this what should be done for the aircraft
engine?
Thanks for your advice.
Ken Johnson
________________________________________________________________________________
| From: | "George, Neal E Capt USAF ACC 505 TRS/DOJ" <Neal.George(at)hurlburt.af.mil> |
Depends on the engine and the application. On most certificated systems,
pulling the mixture shuts off the fuel flow in the metering device
(injection servo or carb) - thus the term Idle Cut-Off (ICO). The fuel
servo manufactured by Airflow Performance, popular among the experimental
crowd, DOES NOT completely stop fuel flow at the low idle stop. Airflow
Performance incorporates a valve to shut off fuel between the servo and the
distribution spider.
Generally speaking, to shut down an aircraft engine we turn off the fuel
supply to starve the engine. The idea is to get the fuel out of the intake
system so that a hot cylinder or un-grounded mag won't fire unexpectedly and
hurt someone. I've had more than one airplane fire a cylinder when
positioning the prop after a run-up for maintenance - with the mags off and
keys in my hand.
Just turning off the ignition is no guarantee and leaves fuel in the system.
Hot aircraft engines will diesel, and the higher the compression, the more
likely it is to happen.
Neal
A&P/IA
-----Original Message-----
On Behalf Of Kenneth Johnson
Aircraft Electrical Gurus,
This subject has been presented briefly recently, but I was looking for the
opinion of several. This may have an electrical solution of not. The
question is: "What is the best way to stop your aircraft engine?
In the recent past, at this site I have seen recommended a switch to the
fuel pump. Turn off the fuel pump and eventually the engine stops.
I rent Cessna 172 and the prefered way to stop the engine is to minimize
both the throttle and richness knobs by pulling them out. Technically, what
exactly does this do? Could I place a simple ball valve on my fuel rail and
phsically close it? Is this what I do on the Cessna 172? The Cessna fuel
is fed throught a carburetor and my engine is fuel injected. Does that make
a difference?
On the automobile engine, when we turn off the engine, are we just closing
the switch that provides current to the spark plugs, or is something else
involved? Is this what should be done for the aircraft engine?
Thanks for your advice.
Ken Johnson
________________________________________________________________________________
| From: | Bob Borger <rlborger(at)mac.com> |
| Subject: | Re: stopping engine |
Ken,
What kind of engine are you using or planning to use? Makes a difference.
My Rotax 914 is shut down by shorting the ignition module output to ground preventing
spark. This method ensures you know that the ignition is properly grounding.
Traditional aircraft engines such as Lycoming and Continental are shut down by
setting the throttle to idle and pulling the mixture control to Idle/cutoff.
This shuts off the fuel going into the engine from either the carb or F/I system.
Makes the engine safe as described by Bruce Gray.
Auto engines are shut down by turning off the key which removes the electrical
source from the ignition, computers & fuel pump, shutting things down all over
the place.
There are valid reasons for each method. You should determine what would be best
for your engine based on the manufacturers recommendations. If you are doing
an automotive conversion, I guess you'd use the automotive method.
Bob Borger
Europa XS Monowheel, Rotax 914 w/ Intercooler, Airmaster C/S prop.
Building a Little Toot Sport Biplane.
On Tuesday, April 27, 2010, at 11:45AM, "Kenneth Johnson"
wrote:
>
________________________________________________________________________________
| Subject: | Pitot heat switch |
| From: | "woxofswa" <woxof(at)aol.com> |
I'm installing a Dynon heated pitot probe in my RV-10. I also have Van's rv-10
wiring kit. In the kit, on some circuits they use a switched circuit breaker and
others they use a switch and a separate breaker. Dynon recommends a 15 amp
breaker.
Would it be better to use a switched breaker or a switch and c/b?
Thanks in advance.
--------
Myron Nelson
Mesa, AZ
Emp completed, QB wings completed, legacy build fuse in progress
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=295891#295891
________________________________________________________________________________
| From: | "Jon Finley" <jon(at)finleyweb.net> |
=0A=0AHi Ken,=0A =0AI too have seen that discussion. For clarity - all of
my comments are in regards to an automotive multi-point EFI engine (not to
be confused with any carbureated engine or any mechanical fuel injection sy
stem).=0A =0AWith my flying Subaru EJ-22, the ignition switch cuts power to
the ECU (Real World Solutions EC2), injectors, and coils. Has worked fine
for 300 hours.=0A =0AI believe (but am not 100% positive) that most modern
automotive EFI systems all shut down the ECU, coils, and injectors when sw
itched off. Talking specifically about automotive EFI engines, I see no va
lue in starving the engine for fuel. I am told (but have no statistics or t
ests to prove) that this can harm a high pressure EFI fuel pump (running it
dry).=0A =0AJon=0A=0A=0A-----Original Message-----=0AFrom: "Kenneth Johnso
n" =0ASent: Tuesday, April 27, 2010 10:45am=0ATo: ae
roelectric-list(at)matronics.com=0ASubject: AeroElectric-List: stopping engine
=0A=0A=0A=0AAircraft Electrical Gurus,=0AThis subject has been presented br
iefly recently, but I was looking for the opinion of several. This may hav
e an electrical solution of not. The question is: "What is the best way to
stop your aircraft engine?=0A =0AIn the recent past, at this site I have s
een recommended a switch to the fuel pump. Turn off the fuel pump and even
tually the engine stops. =0A =0AI rent Cessna 172 and the prefered way to
stop the engine is to minimize both the throttle and richness knobs by pull
ing them out. Technically, what exactly does this do? Could I place a sim
ple ball valve on my fuel rail and phsically close it? Is this what I do o
n the Cessna 172? The Cessna fuel is fed throught a carburetor and my engi
ne is fuel injected. Does that make a difference?=0A =0AOn the automobile
engine, when we turn off the engine, are we just closing the switch that pr
ovides current to the spark plugs, or is something else involved? Is this
what should be done for the aircraft engine?=0A =0AThanks for your advice.
or?AeroElectric-List] http://www.matronics.com/Navigator?AeroElectric-List_
========================
________________________________________________________________________________
| From: | "Matt Prather" <mprather(at)spro.net> |
I think it's worthwhile to be precise (reduce ambiguity) in matters such
as this.
I believe many (most?) light airplane POH's specify that engine shutdown
is accomplished by moving the mixture control to idle-cutoff (ICO).
Usually this causes the engine to stop running fairly rapidly - in a
matter of a couple of seconds. Selecting rich mixture and hitting the
starter usually allows the engine to restart very quickly/easily.
Certainly many airplanes still have Stromberg carbs (or similar) which
don't have a mixture control effective enough to cause "idle-cutoff". I
have ridden with pilots of such airplanes who only use the magneto
switches to stop the engine. One benefit of this procedure is that you
check to see if you have a "hot mag" on each flight. If the engine stops
dead, you can be somewhat certain that the p-lead circuit is in working
condition.
Most (all?) light airplanes also have at least one fuel control valve
(selector), which can also be used to stop the flow of fuel to the engine.
On the carbureted engines that I have operated, closing this fuel valve
does eventually stop the engine, though depending on how low the throttle
setting is, it might take a few minutes for the float bowl in the carb to
get low enough to cause the engine to lean-out and die. Usually when I
pull up to a parking spot, I don't feel like waiting for the carb to
empty, so I never do this.
If the fuel valve was turned off, on carbureted airplanes with gravity
feed fuel, turning on the fuel valve and waiting a few moments will refill
the carb float bowl, at which point the engine may be restarted. For an
airplane with pump driven fuel, turning on the electric pump will allow
restarting much faster/sooner than if only the engine driven pump is used.
Turning on the electric pump is often in the engine start procedure.
In an airplane that depends on a high pressure electric pump, I'm not sure
it makes sense to "turn off the fuel," if that implies closing some kind
of fuel valve. It might make more sense to turn off the electric pump(s).
My impression of automotive fuel injection is that turning the key off
stops power to both the ignition and the fuel pump(s). This leaves
burnable mixture in the cylinders and intake manifold. In an airplane,
this method of stopping the engine increases the risk of unexpected prop
motion. Turning the key to run causes the fuel pump(s) to run until the
specified system pressure is reached, at which point the pump(s) turn off.
One other thing I have noticed is that some electronic ignition systems
may fire the spark plugs one time when the system is energized. This will
likely cause the prop to turn if there is a burnable mixture in the
cylinders. In fact, my Varieze has such a system. A number of times I
have actually had the engine start spontaneously because of this effect -
prime with accelerator pump, walk the prop to pull fuel into the
cylinders, turn on the ignition, and away it goes. So, magnetos aren't
the only things that will fire unexpectedly. In fact, a mag without an
impulse couple isn't likely going to spark on its own..
So to get back to the original question, I agree that stopping the fuel
delivery in some way is generally a good idea. I think turning off the
pumps while leaving the ignition firing is the best bet, as that should
dump fuel system pressure, and yield the least burnable mixture in the
cylinders.
With all that said, everyone working around aircraft should be very
careful of the propeller, whatever method is used to stop the engine.
Pilots need to be vigilant to not allow anyone to haphazardly move the
prop or stand in the prop arc.
Regards,
Matt-
> In an Aviation carbed or injected engine, the shutoff method is the
> same- turn off the fuel. The reason for this is to prevent a fuel/air
> mixture being left in a cylinder. If a P lead wire is broken and the
> propeller is turned, it could fire and injure someone. From your
> question I assume youre installing an auto engine.
>
> Auto engines kill the spark. Some might also kill the pressure in the
> fuel rail. Youre going to have to blas your own trail here.
>
> Bruce
> www.Glasair.org
> -----Original Message-----
> From: owner-aeroelectric-list-server(at)matronics.com
> [mailto:owner-aeroelectric-list-server(at)matronics.com] On Behalf Of
> Kenneth Johnson
> Sent: Tuesday, April 27, 2010 12:45 PM
> To: aeroelectric-list(at)matronics.com
> Subject: AeroElectric-List: stopping engine
>
> Aircraft Electrical Gurus,
> This subject has been presented briefly recently, but I was looking for
> the opinion of several. This may have an electrical solution of not.
> The question is: "What is the best way to stop your aircraft engine?
>
> In the recent past, at this site I have seen recommended a switch to the
> fuel pump. Turn off the fuel pump and eventually the engine stops.
>
> I rent Cessna 172 and the prefered way to stop the engine is to minimize
> both the throttle and richness knobs by pulling them out. Technically,
> what exactly does this do? Could I place a simple ball valve on my fuel
> rail and phsically close it? Is this what I do on the Cessna 172? The
> Cessna fuel is fed throught a carburetor and my engine is fuel injected.
> Does that make a difference?
>
> On the automobile engine, when we turn off the engine, are we just
> closing the switch that provides current to the spark plugs, or is
> something else involved? Is this what should be done for the aircraft
> engine?
>
> Thanks for your advice.
>
> Ken Johnson
>
>
________________________________________________________________________________
| Subject: | Re: Surface temperature sensor |
I'll second that - Jim, thanks for the due diligence. I'm not that
creative at this point so I found a relatively low cost source for a 4
channel display which supports standard thermocouples and can also be
panel mounted. While not their main business, these folks seem keen
towards supplying the aircraft market. http://www.omega.com is sort of a
go-to joint for thermo-stuff. Of course there are hundreds of other
options.
http://www.aprsworld.com/thermok/
Glenn
-----Original Message-----
From: owner-aeroelectric-list-server(at)matronics.com
[mailto:owner-aeroelectric-list-server(at)matronics.com] On Behalf Of
user9253
Sent: Sunday, April 25, 2010 9:32 AM
Subject: AeroElectric-List: Re: Surface temperature sensor
Jim McCulley,
Good job making an economical and accurate multi-point temperature
sensor and indicator. I admire your ingenuity and resourcefulness.
Joe
--------
Joe Gores
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=295622#295622
________________________________________________________________________________
| From: | "Don" <dsvs(at)ca.rr.com> |
| Subject: | Sil Pad For Schottky Diode |
Bob,
I bought a Schottky Diode from you roughly one year ago. I installed it
today and was unable to get the device mounted so that there was no
conductivity between the load screw and the mounting plate. I did not use
excessive force on the screw and the holes are all clean. I think the Sil
Pad got damaged in the install. Can I buy another one from you ?
________________________________________________________________________________
| From: | "DEAN PSIROPOULOS" <dean.psiropoulos(at)verizon.net> |
| Subject: | Looking for info on UPS AT GX-50/60/65 |
Has anyone with a UPS AT GX-50/60/65 panel mount GPS been able to change the
ground speed readout from knots to MPH? I'm trying to finish a ground speed
calibration series and it would be easier if the flight instruments and GPS
had the same speed readouts. I looked through the installation and
operating manuals and didn't find any information on changing KNOTS to MPH.
Anyone ever done this? If so how did you do it?
Dean Psiropoulos
RV-6A N197DM
Flying and finishing touches
________________________________________________________________________________
| From: | "DEAN PSIROPOULOS" <dean.psiropoulos(at)verizon.net> |
| Subject: | Question on PS6000/SL-10 Audio Panel |
My PS engineering 6000 (mfg for UPS AT as the SL-10 MS) intercom has stereo
audio inputs and outputs. The other day I was flying and finally plugged in
my Sandisk mp3 player to enjoy some music while working my airspeed
calibration runs. I had the Sandisk volume set at maximum and had to have
the volume on the PS 6000 at 3/4 maximum to hear the music at a low level.
Also the music sounded a little distorted (not too surprising given the
volume setting on the 6000). I was hoping that there would be a pot on the
circuit board that I could adjust to increase the input sensitivity but
couldn't find anything in the manual about it. The system is set up for
stereo but right now I'm running the mono Sigtronics headset that I
purchased during my "Cessna" days, I have the volume on the headset at
maximum when doing the above test. The 6000 manual says it's ok to plug in
mono headsets so I doubt that the system has been damaged in any way.
Anyone have some words of wisdom on running mp3 and other audio input
devices with aviation intercoms and audio panels? I assumed the audio
inputs needed high level (not speaker level inputs) but maybe the Sandisk
just doesn't have enough oomph. In the short term I plan to convert the mono
headset to Stereo, long term I plan to purchase an ANR Stereo headset of
excellent quality (and unfortunately price). Please advise. Thanks.
Dean Psiropoulos
RV-6A N197DM
Flying and finishing touches
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <nuckolls.bob(at)aeroelectric.com> |
| Subject: | Re: Pitot heat switch |
At 01:02 PM 4/27/2010, you wrote:
>
>I'm installing a Dynon heated pitot probe in my RV-10. I also have
>Van's rv-10 wiring kit. In the kit, on some circuits they use a
>switched circuit breaker and others they use a switch and a separate
>breaker. Dynon recommends a 15 amp breaker.
>Would it be better to use a switched breaker or a switch and c/b?
Your choice. I perceive no difference in
performance.
Bob . . .
________________________________________________________________________________
| Subject: | Narco COM11/11A/120 tray connector |
| From: | "okiairboss" <boss(at)adaairexpo.com> |
This might not be the right forum but I am looking for qty 2 of the Narco 15 pin
white Molex tray connector for the COM11/120 series radios. I am building a
ground based air boss radio rig and can't find connectors anywhere. Can find
trays but none of them have connectors so far.
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=295967#295967
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <nuckolls.bob(at)aeroelectric.com> |
| Subject: | Re: Sil Pad For Schottky Diode |
At 08:39 PM 4/27/2010, you wrote:
>Bob,
>I bought a Schottky Diode from you roughly one year ago. I
>installed it today and was unable to get the device mounted so that
>there was no conductivity between the load screw and the mounting
>plate. I did not use excessive force on the screw and the holes are
>all clean. I think the Sil Pad got damaged in the install. Can I
>buy another one from you ?
Shoot me your address and I'll send you one.
Bob . . .
////
(o o)
===========o00o=(_)=o00o========
< Go ahead, make my day . . . >
< show me where I'm wrong. >
================================
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <nuckolls.bob(at)aeroelectric.com> |
| Subject: | Hour-meter switch from 3-phase tach generator |
Some weeks back we had a discussion about how to switch
a Hobbs meter on and off based on activity at the
3-phase tach generator. I thought we'd 'wrapped up'
that discussion but I found a drawing under a stack
of stuff that apparently didn't get posted. For
those interested in such things, see:
http://aeroelectric.com/Pictures/Schematics/Hour-Meter_from_3-Phase_Tach.pdf
The opto-couplers can be anything with an open
collector, transistor output.
Bob . . .
////
(o o)
===========o00o=(_)=o00o========
< Go ahead, make my day . . . >
< show me where I'm wrong. >
================================
________________________________________________________________________________
| From: | Kevin Sheely <ksheely(at)bellsouth.net> |
| Subject: | One or Two batteries with Single Alternator for Electric |
Airplane
Bob,=0A=0AWhich architecture should I be using for a VFR, day/night, single
engine dual LSE ignition, single B&C 30 amp alternator and single MGL EFIS
, radio, transponder, intercom?=0A=0AMy emergency power draw would be 6.7 a
mps (cruise-is 12.34 amps). I could use a single battery but would like t
o have a second smaller 5-7 amp battery as a backup for the EFIS and-one
of the LSE ignitions.=0A=0ARegards,=0AKevin
________________________________________________________________________________
| From: | Kenneth Johnson <kjohnsondds(at)yahoo.com> |
| Subject: | Re: stopping engine |
Hi All,=0AI would like to thank all who responded.=C2- =0A=0AIt would see
m the best reason to stop an engine with fuel starvation would be to preven
t possible danger from the prop.=C2- If a prop was repositioned, fuel in
a cylinder might ignite, which in turn would turn the prop and that might h
urt someone.=C2- In an automobile, if dieseling=C2-occurs, no is hurt.
=C2- The car is in "Park" or "Neutral."=0A=0AI have a Mazda rotary engine
I will be using for my airplane.=C2- Eventhough this is not a piston eng
ine, the threat of danger from the prop with fuel left in the burn chamber
still exists.=C2- For safety reasons, fuel starvation would be the best w
ay to stop the engine.=C2- Turning off the ignition will stop current to
the spark plugs, coils,=C2-and will turn off the high pressure fuel pump.
=C2- However, it would seem that turning off the fuel pump before turning
off the ignition would be a safer way to eliminate fuel from the burn cham
bers.=0A=0ABy using a valve on my fuel rail, I could stop fuel.=C2- Howev
er, the fuel pump would still be working and could be damaged.=C2- Again,
it would seem that switching off the fuel pump=C2-before the ignition=C2
-might be the best solution.=C2- =0A=0AIf anyone has a better solution,
please post.=0A=0AThanks,=0A=0AKen Johnson=C2-=C2-=0A=0A=0A=0A=0A_____
___________________________=0AFrom: Matt Prather <mprather(at)spro.net>=0ATo:
aeroelectric-list(at)matronics.com=0ASent: Tue, April 27, 2010 1:54:43 PM=0ASu
bject: RE: AeroElectric-List: stopping engine=0A=0A--> AeroElectric-List me
ssage posted by: "Matt Prather" =0A=0AI think it's worth
while to be precise (reduce ambiguity) in matters such=0Aas this.=0A=0AI be
lieve many (most?) light airplane POH's specify that engine shutdown=0Ais a
ccomplished by moving the mixture control to idle-cutoff (ICO).=0AUsually t
his causes the engine to stop running fairly rapidly - in a=0Amatter of a c
ouple of seconds.=C2- Selecting rich mixture and hitting the=0Astarter us
ually allows the engine to restart very quickly/easily.=0A=0ACertainly many
airplanes still have Stromberg carbs (or similar) which=0Adon't have a mix
ture control effective enough to cause "idle-cutoff".=C2- I=0Ahave ridden
with pilots of such airplanes who only use the magneto=0Aswitches to stop
the engine.=C2- One benefit of this procedure is that you=0Acheck to see
if you have a "hot mag" on each flight.=C2- If the engine stops=0Adead, y
ou can be somewhat certain that the p-lead circuit is in working=0Aconditio
n.=0A=0AMost (all?) light airplanes also have at least one fuel control val
ve=0A(selector), which can also be used to stop the flow of fuel to the eng
ine.=0AOn the carbureted engines that I have operated, closing this fuel va
lve=0Adoes eventually stop the engine, though depending on how low the thro
ttle=0Asetting is, it might take a few minutes for the float bowl in the ca
rb to=0Aget low enough to cause the engine to lean-out and die.=C2- Usual
ly when I=0Apull up to a parking spot, I don't feel like waiting for the ca
rb to=0Aempty, so I never do this.=0A=0AIf the fuel valve was turned off, o
n carbureted airplanes with gravity=0Afeed fuel, turning on the fuel valve
and waiting a few moments will refill=0Athe carb float bowl, at which point
the engine may be restarted.=C2- For an=0Aairplane with pump driven fuel
, turning on the electric pump will allow=0Arestarting much faster/sooner t
han if only the engine driven pump is used.=0ATurning on the electric pump
is often in the engine start procedure.=0A=0AIn an airplane that depends on
a high pressure electric pump, I'm not sure=0Ait makes sense to "turn off
the fuel," if that implies closing some kind=0Aof fuel valve.=C2- It migh
t make more sense to turn off the electric pump(s).=0A=0AMy impression of a
utomotive fuel injection is that turning the key off=0Astops power to both
the ignition and the fuel pump(s).=C2- This leaves=0Aburnable mixture in
the cylinders and intake manifold.=C2- In an airplane,=0Athis method of s
topping the engine increases the risk of unexpected prop=0Amotion.=C2- Tu
rning the key to run causes the fuel pump(s) to run until the=0Aspecified s
ystem pressure is reached, at which point the pump(s) turn off.=0A=0AOne ot
her thing I have noticed is that some electronic ignition systems=0Amay fir
e the spark plugs one time when the system is energized.=C2- This will=0A
likely cause the prop to turn if there is a burnable mixture in the=0Acylin
ders.=C2- In fact, my Varieze has such a system.=C2- A number of times
I=0Ahave actually had the engine start spontaneously because of this effect
-=0Aprime with accelerator pump, walk the prop to pull fuel into the=0Acyl
inders, turn on the ignition, and away it goes.=C2- So, magnetos aren't
=0Athe only things that will fire unexpectedly.=C2- In fact, a mag withou
t an=0Aimpulse couple isn't likely going to spark on its own..=0A=0ASo to g
et back to the original question,=C2- I agree that stopping the fuel=0Ade
livery in some way is generally a good idea.=C2- I think turning off the
=0Apumps while leaving the ignition firing is the best bet, as that should
=0Adump fuel system pressure, and yield the least burnable mixture in the
=0Acylinders.=0A=0AWith all that said, everyone working around aircraft sho
uld be very=0Acareful of the propeller, whatever method is used to stop the
engine. =0APilots need to be vigilant to not allow anyone to haphazardly m
ove the=0Aprop or stand in the prop arc.=0A=0A=0ARegards,=0A=0AMatt-=0A=0A>
In an Aviation carb=99ed or injected engine, the shutoff method is t
he=0A> same- turn off the fuel. The reason for this is to prevent a fuel/ai
r=0A> mixture being left in a cylinder. If a P lead wire is broken and the
=0A> propeller is turned, it could fire and injure someone. From your=0A> q
uestion I assume you=99re installing an auto engine.=0A>=0A> Auto eng
ines kill the spark. Some might also kill the pressure in the=0A> fuel rail
. You=99re going to have to blas=C3=A9 your own trail here.=0A>=0A> B
ruce=0A> www.Glasair.org=0A> -----Original Message-----=0A> From: owner-aer
oelectric-list-server(at)matronics.com=0A> [mailto:owner-aeroelectric-list-ser
ver(at)matronics.com] On Behalf Of=0A> Kenneth Johnson=0A> Sent: Tuesday, Apri
l 27, 2010 12:45 PM=0A> To: aeroelectric-list(at)matronics.com=0A> Subject: Ae
roElectric-List: stopping engine=0A>=0A> Aircraft Electrical Gurus,=0A> Thi
s subject has been presented briefly recently, but I was looking for=0A> th
e opinion of several.=C2- This may have an electrical solution of not.=0A
> The question is: "What is the best way to stop your aircraft engine?=0A>
=0A> In the recent past, at this site I have seen recommended a switch to t
he=0A> fuel pump.=C2- Turn off the fuel pump and eventually the engine st
ops.=0A>=0A> I rent Cessna 172 and the prefered way to stop the engine is t
o minimize=0A> both the throttle and richness knobs by pulling them out.=C2
- Technically,=0A> what exactly does this do?=C2- Could I place a simpl
e ball valve on my fuel=0A> rail and phsically close it?=C2- Is this what
I do on the Cessna 172?=C2- The=0A> Cessna fuel is fed throught a carbur
etor and my engine is fuel injected.=0A> Does that make a difference?=0A>
=0A> On the automobile engine, when we turn off the engine, are we just=0A>
closing the switch that provides current to the spark plugs, or is=0A> som
ething else involved?=C2- Is this what should be done for the aircraft=0A
> engine?=0A>=0A> Thanks for your advice.=0A>=0A> Ken Johnson=0A>=0A>=0A>
-========================
=C2- =C2- =C2- =C2- =C2- =C2- =C2- =C2- =C2- =C2- -Matt
=============0A=0A=0A
________________________________________________________________________________
| Subject: | Re: Big load on BAT BUS |
| From: | "jonlaury" <jonlaury(at)impulse.net> |
klehman(at)albedo.net wrote:
> There are details that aren't mentioned but I would be cautious with
> this. ..snip...
>
> To understand where I am coming from, understand that the so called
> "redundant" electronic engine systems that I've examined do not come
> close to true redundancy. Most do not have dual injectors and most share
> a single feed to the injectors.
>
> Ken
>
>
Ken,
Thanks for your observations and I'm sorry for the delayed response. My ISP has
been down for awhile. It's not often that we have rain and low temps in April
in Central Calif and the wireless system antenna on a 6500' peak took a load
of ice and collapsed.
My EFI system is the quasi-redundant type that you referred to. A single ECU, injectors,
TPS, etc. I inquired about "dualing" up the system but they said that
they had tried that and that the result, because of the additional complexities,
was a far less reliable system than the single system. SDS has accumulated
15,000+ flight hours, over 12,000,000 ground ops hours and bench top set up
that has been firing away, 24/7, for years, all without a single equipment failure
that was not caused by customer wiring/installation errors. MTBF far exceeds
that of any reciprocating engine. I decided that the track record that Simple
Digital Systems has accumulated gave me sufficient confidence to run the single
system.
BUT... as long as I had multiple sources of power (2 alts, 1 bat), I wanted to
hedge my bets by connecting my single EFI to all 3, via Z-13. The Z-32 contactor
add-on will be the third power source after losing two alternators.
John
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=296048#296048
________________________________________________________________________________
| Subject: | Re: stopping engine |
| From: | Mike Fontenot <mikef(at)apexconsultingservices.com> |
I have a GEO engine, EFI is the EC2 system, with 2 fuel pumps going into a
single line, then to the fuel rail. In that line is a 3 way valve that I ca
n
use to bypass the rail and spill back into the fuel tank. Turning off the
engine by starving the fuel, yet keeping the pumps running smoothly works
quite well.
On Wed, Apr 28, 2010 at 10:11 AM, Kenneth Johnson wr
ote:
> Hi All,
> I would like to thank all who responded.
>
> It would seem the best reason to stop an engine with fuel starvation woul
d
> be to prevent possible danger from the prop. If a prop was repositioned,
> fuel in a cylinder might ignite, which in turn would turn the prop and th
at
> might hurt someone. In an automobile, if dieseling occurs, no is hurt.
The
> car is in "Park" or "Neutral."
>
> I have a Mazda rotary engine I will be using for my airplane. Eventhough
> this is not a piston engine, the threat of danger from the prop with fuel
> left in the burn chamber still exists. For safety reasons, fuel starvati
on
> would be the best way to stop the engine. Turning off the ignition will
> stop current to the spark plugs, coils, and will turn off the high pressu
re
> fuel pump. However, it would seem that turning off the fuel pump before
> turning off the ignition would be a safer way to eliminate fuel from the
> burn chambers.
>
> By using a valve on my fuel rail, I could stop fuel. However, the fuel
> pump would still be working and could be damaged. Again, it would seem t
hat
> switching off the fuel pump before the ignition might be the best solutio
n.
>
>
> If anyone has a better solution, please post.
>
> Thanks,
>
> Ken Johnson
>
> ------------------------------
> *From:* Matt Prather
> *To:* aeroelectric-list(at)matronics.com
> *Sent:* Tue, April 27, 2010 1:54:43 PM
> *Subject:* RE: AeroElectric-List: stopping engine
>
t
> >
>
> I think it's worthwhile to be precise (reduce ambiguity) in matters such
> as this.
>
> I believe many (most?) light airplane POH's specify that engine shutdown
> is accomplished by moving the mixture control to idle-cutoff (ICO).
> Usually this causes the engine to stop running fairly rapidly - in a
> matter of a couple of seconds. Selecting rich mixture and hitting the
> starter usually allows the engine to restart very quickly/easily.
>
> Certainly many airplanes still have Stromberg carbs (or similar) which
> don't have a mixture control effective enough to cause "idle-cutoff". I
> have ridden with pilots of such airplanes who only use the magneto
> switches to stop the engine. One benefit of this procedure is that you
> check to see if you have a "hot mag" on each flight. If the engine stops
> dead, you can be somewhat certain that the p-lead circuit is in working
> condition.
>
> Most (all?) light airplanes also have at least one fuel control valve
> (selector), which can also be used to stop the flow of fuel to the engine
.
> On the carbureted engines that I have operated, closing this fuel valve
> does eventually stop the engine, though depending on how low the throttle
> setting is, it might take a few minutes for the float bowl in the carb to
> get low enough to cause the engine to lean-out and die. Usually when I
> pull up to a parking spot, I don't feel like waiting for the carb to
> empty, so I never do this.
>
> If the fuel valve was turned off, on carbureted airplanes with gravity
> feed fuel, turning on the fuel valve and waiting a few moments will refil
l
> the carb float bowl, at which point the engine may be restarted. For an
> airplane with pump driven fuel, turning on the electric pump will allow
> restarting much faster/sooner than if only the engine driven pump is used
.
> Turning on the electric pump is often in the engine start procedure.
>
> In an airplane that depends on a high pressure electric pump, I'm not sur
e
> it makes sense to "turn off the fuel," if that implies closing some kind
> of fuel valve. It might make more sense to turn off the electric pump(s)
.
>
> My impression of automotive fuel injection is that turning the key off
> stops power to both the ignition and the fuel pump(s). This leaves
> burnable mixture in the cylinders and intake manifold. In an airplane,
> this method of stopping the engine increases the risk of unexpected prop
> motion. Turning the key to run causes the fuel pump(s) to run until the
> specified system pressure is reached, at which point the pump(s) turn off
.
>
> One other thing I have noticed is that some electronic ignition systems
> may fire the spark plugs one time when the system is energized. This wil
l
> likely cause the prop to turn if there is a burnable mixture in the
> cylinders. In fact, my Varieze has such a system. A number of times I
> have actually had the engine start spontaneously because of this effect -
> prime with accelerator pump, walk the prop to pull fuel into the
> cylinders, turn on the ignition, and away it goes. So, magnetos aren't
> the only things that will fire unexpectedly. In fact, a mag without an
> impulse couple isn't likely going to spark on its own..
>
> So to get back to the original question, I agree that stopping the fuel
> delivery in some way is generally a good idea. I think turning off the
> pumps while leaving the ignition firing is the best bet, as that should
> dump fuel system pressure, and yield the least burnable mixture in the
> cylinders.
>
> With all that said, everyone working around aircraft should be very
> careful of the propeller, whatever method is used to stop the engine.
> Pilots need to be vigilant to not allow anyone to haphazardly move the
> prop or stand in the prop arc.
>
>
> Regards,
>
> Matt-
>
> > In an Aviation carb=92ed or injected engine, the shutoff method is the
> > same- turn off the fuel. The reason for this is to prevent a fuel/air
> > mixture being left in a cylinder. If a P lead wire is broken and the
> > propeller is turned, it could fire and injure someone. From your
> > question I assume you=92re installing an auto engine.
> >
> > Auto engines kill the spark. Some might also kill the pressure in the
> > fuel rail. You=92re going to have to blas=E9 your own trail here.
> >
> > Bruce
> > www.Glasair.org <http://www.glasair.org/>
> > -----Original Message-----
> > From: owner-aeroelectric-list-server(at)matronics.com
> > [mailto:owner-aeroelectric-list-server(at)matronics.com] On Behalf Of
> > Kenneth Johnson
> > Sent: Tuesday, April 27, 2010 12:45 PM
> > To: aeroelectric-list(at)matronics.com
> > Subject: AeroElectric-List: stopping engine
> >
> > Aircraft Electrical Gurus,
> > This subject has been presented briefly recently, but I was looking for
> > the opinion of several. This may have an electrical solution of not.
> > The question is: "What is the best way to stop your aircraft engine?
> >
> > In the recent past, at this site I have seen recommended a switch to th
e
> > fuel pump. Turn off the fuel pump and eventually the engine stops.
> >
> > I rent Cessna 172 and the prefered way to stop the engine is to minimiz
e
> > both the throttle and richness knobs by pulling them out. Technically,
> > what exactly does this do? Could I place a simple ball valve on my fue
l
> > rail and phsically close it? Is this what I do on the Cessna 172? The
> > Cessna fuel is fed throught a carburetor and my engine is fuel injected
.
> > Does that make a difference?
> >
> > On the automobile engine, when we turn off the engine, are we just
> > closing the switch that provides current to the spark plugs, or is
> > something else involved? Is this what should be done for the aircraft
> > engine?
> >
> > Thanks for your advice.
> >
> > Ken Johnson
> >
> >
> >
> >
>
>
> *
>
===========
===========
===========
===========
> *
>
>
--
Mike
======
Mike Fontenot
Apex Consulting & Services LLC
Lakewood, Colorado
303 / 731-6645
mikef AT apexconsultingservices DOT com
======
________________________________________________________________________________
| From: | "Bill Bradburry" <bbradburry(at)bellsouth.net> |
Ken,
You didn=92t say if you have fuel injection or a carb on your Mazda
rotary,
but if you have FI, you can shut off the injectors and the engine will
immediately stop due to fuel starvation. No fuel will be left in the
rotor
faces. The fuel regulator will then immediately open up to keep the
fuel
pressure at your set point, so the fuel pumps will not be adversely
affected. In fact, this is the condition you will have the regulator
and
pumps in when you set the fuel pressure. This is the way it is designed
to
work so no damage will ensue. After the engine stops you can leisurely
shut
everything else down. There will be no fuel in the rotors so there will
be
no danger if you want to move the prop for whatever reason.
If you have a carb, well, you are on your own.. :>)
Bill B
_____
From: owner-aeroelectric-list-server(at)matronics.com
[mailto:owner-aeroelectric-list-server(at)matronics.com] On Behalf Of
Kenneth
Johnson
Sent: Wednesday, April 28, 2010 12:11 PM
Subject: Re: AeroElectric-List: stopping engine
Hi All,
I would like to thank all who responded.
It would seem the best reason to stop an engine with fuel starvation
would
be to prevent possible danger from the prop. If a prop was
repositioned,
fuel in a cylinder might ignite, which in turn would turn the prop and
that
might hurt someone. In an automobile, if dieseling occurs, no is hurt.
The
car is in "Park" or "Neutral."
I have a Mazda rotary engine I will be using for my airplane.
Eventhough
this is not a piston engine, the threat of danger from the prop with
fuel
left in the burn chamber still exists. For safety reasons, fuel
starvation
would be the best way to stop the engine. Turning off the ignition will
stop current to the spark plugs, coils, and will turn off the high
pressure
fuel pump. However, it would seem that turning off the fuel pump before
turning off the ignition would be a safer way to eliminate fuel from the
burn chambers.
By using a valve on my fuel rail, I could stop fuel. However, the fuel
pump
would still be working and could be damaged. Again, it would seem that
switching off the fuel pump before the ignition might be the best
solution.
If anyone has a better solution, please post.
Thanks,
Ken Johnson
_____
From: Matt Prather <mprather(at)spro.net>
Sent: Tue, April 27, 2010 1:54:43 PM
Subject: RE: AeroElectric-List: stopping engine
I think it's worthwhile to be precise (reduce ambiguity) in matters such
as this.
I believe many (most?) light airplane POH's specify that engine shutdown
is accomplished by moving the mixture control to idle-cutoff (ICO).
Usually this causes the engine to stop running fairly rapidly - in a
matter of a couple of seconds. Selecting rich mixture and hitting the
starter usually allows the engine to restart very quickly/easily.
Certainly many airplanes still have Stromberg carbs (or similar) which
don't have a mixture control effective enough to cause "idle-cutoff". I
have ridden with pilots of such airplanes who only use the magneto
switches to stop the engine. One benefit of this procedure is that you
check to see if you have a "hot mag" on each flight. If the engine
stops
dead, you can be somewhat certain that the p-lead circuit is in working
condition.
Most (all?) light airplanes also have at least one fuel control valve
(selector), which can also be used to stop the flow of fuel to the
engine.
On the carbureted engines that I have operated, closing this fuel valve
does eventually stop the engine, though depending on how low the
throttle
setting is, it might take a few minutes for the float bowl in the carb
to
get low enough to cause the engine to lean-out and die. Usually when I
pull up to a parking spot, I don't feel like waiting for the carb to
empty, so I never do this.
If the fuel valve was turned off, on carbureted airplanes with gravity
feed fuel, turning on the fuel valve and waiting a few moments will
refill
the carb float bowl, at which point the engine may be restarted. For an
airplane with pump driven fuel, turning on the electric pump will allow
restarting much faster/sooner than if only the engine driven pump is
used.
Turning on the electric pump is often in the engine start procedure.
In an airplane that depends on a high pressure electric pump, I'm not
sure
it makes sense to "turn off the fuel," if that implies closing some kind
of fuel valve. It might make more sense to turn off the electric
pump(s).
My impression of automotive fuel injection is that turning the key off
stops power to both the ignition and the fuel pump(s). This leaves
burnable mixture in the cylinders and intake manifold. In an airplane,
this method of stopping the engine increases the risk of unexpected prop
motion. Turning the key to run causes the fuel pump(s) to run until the
specified system pressure is reached, at which point the pump(s) turn
off.
One other thing I have noticed is that some electronic ignition systems
may fire the spark plugs one time when the system is energized. This
will
likely cause the prop to turn if there is a burnable mixture in the
cylinders. In fact, my Varieze has such a system. A number of times I
have actually had the engine start spontaneously because of this effect
-
prime with accelerator pump, walk the prop to pull fuel into the
cylinders, turn on the ignition, and away it goes. So, magnetos aren't
the only things that will fire unexpectedly. In fact, a mag without an
impulse couple isn't likely going to spark on its own..
So to get back to the original question, I agree that stopping the fuel
delivery in some way is generally a good idea. I think turning off the
pumps while leaving the ignition firing is the best bet, as that should
dump fuel system pressure, and yield the least burnable mixture in the
cylinders.
With all that said, everyone working around aircraft should be very
careful of the propeller, whatever method is used to stop the engine.
Pilots need to be vigilant to not allow anyone to haphazardly move the
prop or stand in the prop arc.
Regards,
Matt-
> In an Aviation carb=92ed or injected engine, the shutoff method is the
> same- turn off the fuel. The reason for this is to prevent a fuel/air
> mixture being left in a cylinder. If a P lead wire is broken and the
> propeller is turned, it could fire and injure someone. From your
> question I assume you=92re installing an auto engine.
>
> Auto engines kill the spark. Some might also kill the pressure in the
> fuel rail. You=92re going to have to blas=E9 your own trail here.
>
> Bruce
> www.Glasair.org <http://www.glasair.org/>
> -----Original Message-----
> From: owner-aeroelectric-list-server(at)matronics.com
> [mailto:owner-aeroelectric-list-server(at)matronics.com] On Behalf Of
> Kenneth Johnson
> Sent: Tuesday, April 27, 2010 12:45 PM
> To: aeroelectric-list(at)matronics.com
> Subject: AeroElectric-List: stopping engine
>
> Aircraft Electrical Gurus,
> This subject has been presented briefly recently, but I was looking
for
> the opinion of several. This may have an electrical solution of not.
> The question is: "What is the best way to stop your aircraft engine?
>
> In the recent past, at this site I have seen recommended a switch to
the
> fuel pump. Turn off the fuel pump and eventually the engine stops.
>
> I rent Cessna 172 and the prefered way to stop the engine is to
minimize
> both the throttle and richness knobs by pulling them out.
Technically,
> what exactly does this do? Could I place a simple ball valve on my
fuel
> rail and phsically close it? Is this what I do on the Cessna 172?
The
> Cessna fuel is fed throught a carburetor and my engine is fuel
injected.
> Does that make a difference?
>
> On the automobile engine, when we turn off the engine, are we just
> closing the switch that provides current to the spark plugs, or is
> something else involved? Is this what should be done for the aircraft
> engine?
>
> Thanks for your advice.
>
> Ken Johnson
>
>
>| From: | "Bill Bradburry" <bbradburry(at)bellsouth.net> |
Ken,
If you are building a Mazda rotary for your plane you should really look
into the rotary forum. There is a tremendous amount of knowledge
available
there. Come join us!
http://mail.lancaironline.net:81/lists/flyrotary/List.html
How to subscribe is at the lower right corner.
Bill B
_____
From: owner-aeroelectric-list-server(at)matronics.com
[mailto:owner-aeroelectric-list-server(at)matronics.com] On Behalf Of
Kenneth
Johnson
Sent: Wednesday, April 28, 2010 12:11 PM
Subject: Re: AeroElectric-List: stopping engine
Hi All,
I would like to thank all who responded.
It would seem the best reason to stop an engine with fuel starvation
would
be to prevent possible danger from the prop. If a prop was
repositioned,
fuel in a cylinder might ignite, which in turn would turn the prop and
that
might hurt someone. In an automobile, if dieseling occurs, no is hurt.
The
car is in "Park" or "Neutral."
I have a Mazda rotary engine I will be using for my airplane.
Eventhough
this is not a piston engine, the threat of danger from the prop with
fuel
left in the burn chamber still exists. For safety reasons, fuel
starvation
would be the best way to stop the engine. Turning off the ignition will
stop current to the spark plugs, coils, and will turn off the high
pressure
fuel pump. However, it would seem that turning off the fuel pump before
turning off the ignition would be a safer way to eliminate fuel from the
burn chambers.
By using a valve on my fuel rail, I could stop fuel. However, the fuel
pump
would still be working and could be damaged. Again, it would seem that
switching off the fuel pump before the ignition might be the best
solution.
If anyone has a better solution, please post.
Thanks,
Ken Johnson
_____
From: Matt Prather <mprather(at)spro.net>
Sent: Tue, April 27, 2010 1:54:43 PM
Subject: RE: AeroElectric-List: stopping engine
I think it's worthwhile to be precise (reduce ambiguity) in matters such
as this.
I believe many (most?) light airplane POH's specify that engine shutdown
is accomplished by moving the mixture control to idle-cutoff (ICO).
Usually this causes the engine to stop running fairly rapidly - in a
matter of a couple of seconds. Selecting rich mixture and hitting the
starter usually allows the engine to restart very quickly/easily.
Certainly many airplanes still have Stromberg carbs (or similar) which
don't have a mixture control effective enough to cause "idle-cutoff". I
have ridden with pilots of such airplanes who only use the magneto
switches to stop the engine. One benefit of this procedure is that you
check to see if you have a "hot mag" on each flight. If the engine
stops
dead, you can be somewhat certain that the p-lead circuit is in working
condition.
Most (all?) light airplanes also have at least one fuel control valve
(selector), which can also be used to stop the flow of fuel to the
engine.
On the carbureted engines that I have operated, closing this fuel valve
does eventually stop the engine, though depending on how low the
throttle
setting is, it might take a few minutes for the float bowl in the carb
to
get low enough to cause the engine to lean-out and die. Usually when I
pull up to a parking spot, I don't feel like waiting for the carb to
empty, so I never do this.
If the fuel valve was turned off, on carbureted airplanes with gravity
feed fuel, turning on the fuel valve and waiting a few moments will
refill
the carb float bowl, at which point the engine may be restarted. For an
airplane with pump driven fuel, turning on the electric pump will allow
restarting much faster/sooner than if only the engine driven pump is
used.
Turning on the electric pump is often in the engine start procedure.
In an airplane that depends on a high pressure electric pump, I'm not
sure
it makes sense to "turn off the fuel," if that implies closing some kind
of fuel valve. It might make more sense to turn off the electric
pump(s).
My impression of automotive fuel injection is that turning the key off
stops power to both the ignition and the fuel pump(s). This leaves
burnable mixture in the cylinders and intake manifold. In an airplane,
this method of stopping the engine increases the risk of unexpected prop
motion. Turning the key to run causes the fuel pump(s) to run until the
specified system pressure is reached, at which point the pump(s) turn
off.
One other thing I have noticed is that some electronic ignition systems
may fire the spark plugs one time when the system is energized. This
will
likely cause the prop to turn if there is a burnable mixture in the
cylinders. In fact, my Varieze has such a system. A number of times I
have actually had the engine start spontaneously because of this effect
-
prime with accelerator pump, walk the prop to pull fuel into the
cylinders, turn on the ignition, and away it goes. So, magnetos aren't
the only things that will fire unexpectedly. In fact, a mag without an
impulse couple isn't likely going to spark on its own..
So to get back to the original question, I agree that stopping the fuel
delivery in some way is generally a good idea. I think turning off the
pumps while leaving the ignition firing is the best bet, as that should
dump fuel system pressure, and yield the least burnable mixture in the
cylinders.
With all that said, everyone working around aircraft should be very
careful of the propeller, whatever method is used to stop the engine.
Pilots need to be vigilant to not allow anyone to haphazardly move the
prop or stand in the prop arc.
Regards,
Matt-
> In an Aviation carb=92ed or injected engine, the shutoff method is the
> same- turn off the fuel. The reason for this is to prevent a fuel/air
> mixture being left in a cylinder. If a P lead wire is broken and the
> propeller is turned, it could fire and injure someone. From your
> question I assume you=92re installing an auto engine.
>
> Auto engines kill the spark. Some might also kill the pressure in the
> fuel rail. You=92re going to have to blas=E9 your own trail here.
>
> Bruce
> www.Glasair.org <http://www.glasair.org/>
> -----Original Message-----
> From: owner-aeroelectric-list-server(at)matronics.com
> [mailto:owner-aeroelectric-list-server(at)matronics.com] On Behalf Of
> Kenneth Johnson
> Sent: Tuesday, April 27, 2010 12:45 PM
> To: aeroelectric-list(at)matronics.com
> Subject: AeroElectric-List: stopping engine
>
> Aircraft Electrical Gurus,
> This subject has been presented briefly recently, but I was looking
for
> the opinion of several. This may have an electrical solution of not.
> The question is: "What is the best way to stop your aircraft engine?
>
> In the recent past, at this site I have seen recommended a switch to
the
> fuel pump. Turn off the fuel pump and eventually the engine stops.
>
> I rent Cessna 172 and the prefered way to stop the engine is to
minimize
> both the throttle and richness knobs by pulling them out.
Technically,
> what exactly does this do? Could I place a simple ball valve on my
fuel
> rail and phsically close it? Is this what I do on the Cessna 172?
The
> Cessna fuel is fed throught a carburetor and my engine is fuel
injected.
> Does that make a difference?
>
> On the automobile engine, when we turn off the engine, are we just
> closing the switch that provides current to the spark plugs, or is
> something else involved? Is this what should be done for the aircraft
> engine?
>
> Thanks for your advice.
>
> Ken Johnson
>
>
>| Date: | Apr 28, 2010 |
| From: | "Matt Prather" <mprather(at)spro.net> |
Bill,
My only concern about this (and it's probably a remote concern) is that if
you have a leaking injector, it may dribble fuel into the engine after
shutdown. Otherwise, this is very much analogous to pulling the mixture
to ICO on an aircraft carb or mechanical injection.
Matt-
> Ken,
>
> You didnt say if you have fuel injection or a carb on your Mazda rotary,
> but if you have FI, you can shut off the injectors and the engine will
> immediately stop due to fuel starvation. No fuel will be left in the
> rotor
> faces. The fuel regulator will then immediately open up to keep the fuel
> pressure at your set point, so the fuel pumps will not be adversely
> affected. In fact, this is the condition you will have the regulator and
> pumps in when you set the fuel pressure. This is the way it is designed
> to
> work so no damage will ensue. After the engine stops you can leisurely
> shut
> everything else down. There will be no fuel in the rotors so there will
> be
> no danger if you want to move the prop for whatever reason.
>
> If you have a carb, well, you are on your own.. :>)
>
>
> Bill B
>
>
> _____
>
> From: owner-aeroelectric-list-server(at)matronics.com
> [mailto:owner-aeroelectric-list-server(at)matronics.com] On Behalf Of Kenneth
> Johnson
> Sent: Wednesday, April 28, 2010 12:11 PM
> To: aeroelectric-list(at)matronics.com
> Subject: Re: AeroElectric-List: stopping engine
>
>
> Hi All,
>
> I would like to thank all who responded.
>
>
> It would seem the best reason to stop an engine with fuel starvation would
> be to prevent possible danger from the prop. If a prop was repositioned,
> fuel in a cylinder might ignite, which in turn would turn the prop and
> that
> might hurt someone. In an automobile, if dieseling occurs, no is hurt.
> The
> car is in "Park" or "Neutral."
>
>
> I have a Mazda rotary engine I will be using for my airplane. Eventhough
> this is not a piston engine, the threat of danger from the prop with fuel
> left in the burn chamber still exists. For safety reasons, fuel
> starvation
> would be the best way to stop the engine. Turning off the ignition will
> stop current to the spark plugs, coils, and will turn off the high
> pressure
> fuel pump. However, it would seem that turning off the fuel pump before
> turning off the ignition would be a safer way to eliminate fuel from the
> burn chambers.
>
>
> By using a valve on my fuel rail, I could stop fuel. However, the fuel
> pump
> would still be working and could be damaged. Again, it would seem that
> switching off the fuel pump before the ignition might be the best
> solution.
>
>
> If anyone has a better solution, please post.
>
>
> Thanks,
>
>
> Ken Johnson
>
>
> _____
>
> From: Matt Prather <mprather(at)spro.net>
> To: aeroelectric-list(at)matronics.com
> Sent: Tue, April 27, 2010 1:54:43 PM
> Subject: RE: AeroElectric-List: stopping engine
>
>
>
> I think it's worthwhile to be precise (reduce ambiguity) in matters such
> as this.
>
> I believe many (most?) light airplane POH's specify that engine shutdown
> is accomplished by moving the mixture control to idle-cutoff (ICO).
> Usually this causes the engine to stop running fairly rapidly - in a
> matter of a couple of seconds. Selecting rich mixture and hitting the
> starter usually allows the engine to restart very quickly/easily.
>
> Certainly many airplanes still have Stromberg carbs (or similar) which
> don't have a mixture control effective enough to cause "idle-cutoff". I
> have ridden with pilots of such airplanes who only use the magneto
> switches to stop the engine. One benefit of this procedure is that you
> check to see if you have a "hot mag" on each flight. If the engine stops
> dead, you can be somewhat certain that the p-lead circuit is in working
> condition.
>
> Most (all?) light airplanes also have at least one fuel control valve
> (selector), which can also be used to stop the flow of fuel to the engine.
> On the carbureted engines that I have operated, closing this fuel valve
> does eventually stop the engine, though depending on how low the throttle
> setting is, it might take a few minutes for the float bowl in the carb to
> get low enough to cause the engine to lean-out and die. Usually when I
> pull up to a parking spot, I don't feel like waiting for the carb to
> empty, so I never do this.
>
> If the fuel valve was turned off, on carbureted airplanes with gravity
> feed fuel, turning on the fuel valve and waiting a few moments will refill
> the carb float bowl, at which point the engine may be restarted. For an
> airplane with pump driven fuel, turning on the electric pump will allow
> restarting much faster/sooner than if only the engine driven pump is used.
> Turning on the electric pump is often in the engine start procedure.
>
> In an airplane that depends on a high pressure electric pump, I'm not sure
> it makes sense to "turn off the fuel," if that implies closing some kind
> of fuel valve. It might make more sense to turn off the electric pump(s).
>
> My impression of automotive fuel injection is that turning the key off
> stops power to both the ignition and the fuel pump(s). This leaves
> burnable mixture in the cylinders and intake manifold. In an airplane,
> this method of stopping the engine increases the risk of unexpected prop
> motion. Turning the key to run causes the fuel pump(s) to run until the
> specified system pressure is reached, at which point the pump(s) turn off.
>
> One other thing I have noticed is that some electronic ignition systems
> may fire the spark plugs one time when the system is energized. This will
> likely cause the prop to turn if there is a burnable mixture in the
> cylinders. In fact, my Varieze has such a system. A number of times I
> have actually had the engine start spontaneously because of this effect -
> prime with accelerator pump, walk the prop to pull fuel into the
> cylinders, turn on the ignition, and away it goes. So, magnetos aren't
> the only things that will fire unexpectedly. In fact, a mag without an
> impulse couple isn't likely going to spark on its own..
>
> So to get back to the original question, I agree that stopping the fuel
> delivery in some way is generally a good idea. I think turning off the
> pumps while leaving the ignition firing is the best bet, as that should
> dump fuel system pressure, and yield the least burnable mixture in the
> cylinders.
>
> With all that said, everyone working around aircraft should be very
> careful of the propeller, whatever method is used to stop the engine.
> Pilots need to be vigilant to not allow anyone to haphazardly move the
> prop or stand in the prop arc.
>
>
> Regards,
>
> Matt-
>
>> In an Aviation carbed or injected engine, the shutoff method is the
>> same- turn off the fuel. The reason for this is to prevent a fuel/air
>> mixture being left in a cylinder. If a P lead wire is broken and the
>> propeller is turned, it could fire and injure someone. From your
>> question I assume youre installing an auto engine.
>>
>> Auto engines kill the spark. Some might also kill the pressure in the
>> fuel rail. Youre going to have to blas your own trail here.
>>
>> Bruce
>> www.Glasair.org <http://www.glasair.org/>
>> -----Original Message-----
>> From: owner-aeroelectric-list-server(at)matronics.com
>> [mailto:owner-aeroelectric-list-server(at)matronics.com] On Behalf Of
>> Kenneth Johnson
>> Sent: Tuesday, April 27, 2010 12:45 PM
>> To: aeroelectric-list(at)matronics.com
>> Subject: AeroElectric-List: stopping engine
>>
>> Aircraft Electrical Gurus,
>> This subject has been presented briefly recently, but I was looking for
>> the opinion of several. This may have an electrical solution of not.
>> The question is: "What is the best way to stop your aircraft engine?
>>
>> In the recent past, at this site I have seen recommended a switch to the
>> fuel pump. Turn off the fuel pump and eventually the engine stops.
>>
>> I rent Cessna 172 and the prefered way to stop the engine is to minimize
>> both the throttle and richness knobs by pulling them out. Technically,
>> what exactly does this do? Could I place a simple ball valve on my fuel
>> rail and phsically close it? Is this what I do on the Cessna 172? The
>> Cessna fuel is fed throught a carburetor and my engine is fuel injected.
>> Does that make a difference?
>>
>> On the automobile engine, when we turn off the engine, are we just
>> closing the switch that provides current to the spark plugs, or is
>> something else involved? Is this what should be done for the aircraft
>> engine?
>>
>> Thanks for your advice.
>>
>> Ken Johnson
>>
>>
>>
>>
>
________________________________________________________________________________
| Subject: | Electrical diagram |
| From: | "marchudson" <marchudson(at)verizon.net> |
Was wondering if you guys could have a look at this diagram and tell me what you
think. It is a variation of Z-11. A couple of things about the design. Aircraft
will be flown IMC. Two EFIS panels with internal battery backup. The
alternator is a Plane Power with internal regulator and crowbar over voltage protection.
I talked to the engineers at Plane Power and they told me that that
alternator would function just fine if the battery were hypothetically removed
from the aircraft while it was running, hence no off-batt-gen switch. The
start enable switch will be guarded and is an added safety item to the push button
start. I have tried to consider as many failure modes as possible but am
not nearly as savvy as many on this forum. Thanks in advance for inputs.
Marc
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=296088#296088
Attachments:
http://forums.matronics.com//files/elec_schematic11_667.jpg
________________________________________________________________________________
| From: | "Bill Schertz" <wschertz(at)comcast.net> |
| Subject: | Re: stopping engine |
I have Mazda Rotary with EC-2 and electric fuel pump. shut down consists
of shutting off the fuel pump, engine dies quickly, and there is no
residual pressure in the lines to leak past the injectors and cause
flooding or richness on the start.
Bill Schertz
KIS Cruiser #4045
N343BS
Phase I testing
From: Bill Bradburry
Sent: Wednesday, April 28, 2010 12:09 PM
Subject: RE: AeroElectric-List: stopping engine
Ken,
You didn't say if you have fuel injection or a carb on your Mazda
rotary, but if you have FI, you can shut off the injectors and the
engine will immediately stop due to fuel starvation. No fuel will be
left in the rotor faces. The fuel regulator will then immediately open
up to keep the fuel pressure at your set point, so the fuel pumps will
not be adversely affected. In fact, this is the condition you will have
the regulator and pumps in when you set the fuel pressure. This is the
way it is designed to work so no damage will ensue. After the engine
stops you can leisurely shut everything else down. There will be no
fuel in the rotors so there will be no danger if you want to move the
prop for whatever reason.
If you have a carb, well, you are on your own.. :>)
Bill B
-------------------------------------------------------------------------
-------
From: owner-aeroelectric-list-server(at)matronics.com
[mailto:owner-aeroelectric-list-server(at)matronics.com] On Behalf Of
Kenneth Johnson
Sent: Wednesday, April 28, 2010 12:11 PM
Subject: Re: AeroElectric-List: stopping engine
Hi All,
I would like to thank all who responded.
It would seem the best reason to stop an engine with fuel starvation
would be to prevent possible danger from the prop. If a prop was
repositioned, fuel in a cylinder might ignite, which in turn would turn
the prop and that might hurt someone. In an automobile, if dieseling
occurs, no is hurt. The car is in "Park" or "Neutral."
I have a Mazda rotary engine I will be using for my airplane.
Eventhough this is not a piston engine, the threat of danger from the
prop with fuel left in the burn chamber still exists. For safety
reasons, fuel starvation would be the best way to stop the engine.
Turning off the ignition will stop current to the spark plugs, coils,
and will turn off the high pressure fuel pump. However, it would seem
that turning off the fuel pump before turning off the ignition would be
a safer way to eliminate fuel from the burn chambers.
By using a valve on my fuel rail, I could stop fuel. However, the fuel
pump would still be working and could be damaged. Again, it would seem
that switching off the fuel pump before the ignition might be the best
solution.
If anyone has a better solution, please post.
Thanks,
Ken Johnson
-------------------------------------------------------------------------
-------
From: Matt Prather <mprather(at)spro.net>
Sent: Tue, April 27, 2010 1:54:43 PM
Subject: RE: AeroElectric-List: stopping engine
I think it's worthwhile to be precise (reduce ambiguity) in matters such
as this.
I believe many (most?) light airplane POH's specify that engine shutdown
is accomplished by moving the mixture control to idle-cutoff (ICO).
Usually this causes the engine to stop running fairly rapidly - in a
matter of a couple of seconds. Selecting rich mixture and hitting the
starter usually allows the engine to restart very quickly/easily.
Certainly many airplanes still have Stromberg carbs (or similar) which
don't have a mixture control effective enough to cause "idle-cutoff". I
have ridden with pilots of such airplanes who only use the magneto
switches to stop the engine. One benefit of this procedure is that you
check to see if you have a "hot mag" on each flight. If the engine
stops
dead, you can be somewhat certain that the p-lead circuit is in working
condition.
Most (all?) light airplanes also have at least one fuel control valve
(selector), which can also be used to stop the flow of fuel to the
engine.
On the carbureted engines that I have operated, closing this fuel valve
does eventually stop the engine, though depending on how low the
throttle
setting is, it might take a few minutes for the float bowl in the carb
to
get low enough to cause the engine to lean-out and die. Usually when I
pull up to a parking spot, I don't feel like waiting for the carb to
empty, so I never do this.
If the fuel valve was turned off, on carbureted airplanes with gravity
feed fuel, turning on the fuel valve and waiting a few moments will
refill
the carb float bowl, at which point the engine may be restarted. For an
airplane with pump driven fuel, turning on the electric pump will allow
restarting much faster/sooner than if only the engine driven pump is
used.
Turning on the electric pump is often in the engine start procedure.
In an airplane that depends on a high pressure electric pump, I'm not
sure
it makes sense to "turn off the fuel," if that implies closing some kind
of fuel valve. It might make more sense to turn off the electric
pump(s).
My impression of automotive fuel injection is that turning the key off
stops power to both the ignition and the fuel pump(s). This leaves
burnable mixture in the cylinders and intake manifold. In an airplane,
this method of stopping the engine increases the risk of unexpected prop
motion. Turning the key to run causes the fuel pump(s) to run until the
specified system pressure is reached, at which point the pump(s) turn
off.
One other thing I have noticed is that some electronic ignition systems
may fire the spark plugs one time when the system is energized. This
will
likely cause the prop to turn if there is a burnable mixture in the
cylinders. In fact, my Varieze has such a system. A number of times I
have actually had the engine start spontaneously because of this effect
-
prime with accelerator pump, walk the prop to pull fuel into the
cylinders, turn on the ignition, and away it goes. So, magnetos aren't
the only things that will fire unexpectedly. In fact, a mag without an
impulse couple isn't likely going to spark on its own..
So to get back to the original question, I agree that stopping the fuel
delivery in some way is generally a good idea. I think turning off the
pumps while leaving the ignition firing is the best bet, as that should
dump fuel system pressure, and yield the least burnable mixture in the
cylinders.
With all that said, everyone working around aircraft should be very
careful of the propeller, whatever method is used to stop the engine.
Pilots need to be vigilant to not allow anyone to haphazardly move the
prop or stand in the prop arc.
Regards,
Matt-
> In an Aviation carb'ed or injected engine, the shutoff method is the
> same- turn off the fuel. The reason for this is to prevent a fuel/air
> mixture being left in a cylinder. If a P lead wire is broken and the
> propeller is turned, it could fire and injure someone. From your
> question I assume you're installing an auto engine.
>
> Auto engines kill the spark. Some might also kill the pressure in the
> fuel rail. You're going to have to blas=E9 your own trail here.
>
> Bruce
> www.Glasair.org
> -----Original Message-----
> From: owner-aeroelectric-list-server(at)matronics.com
> [mailto:owner-aeroelectric-list-server(at)matronics.com] On Behalf Of
> Kenneth Johnson
> Sent: Tuesday, April 27, 2010 12:45 PM
> To: aeroelectric-list(at)matronics.com
> Subject: AeroElectric-List: stopping engine
>
> Aircraft Electrical Gurus,
> This subject has been presented briefly recently, but I was looking
for
> the opinion of several. This may have an electrical solution of not.
> The question is: "What is the best way to stop your aircraft engine?
>
> In the recent past, at this site I have seen recommended a switch to
the
> fuel pump. Turn off the fuel pump and eventually the engine stops.
>
> I rent Cessna 172 and the prefered way to stop the engine is to
minimize
> both the throttle and richness knobs by pulling them out.
Technically,
> what exactly does this do? Could I place a simple ball valve on my
fuel
> rail and phsically close it? Is this what I do on the Cessna 172?
The
> Cessna fuel is fed throught a carburetor and my engine is fuel
injected.
> Does that make a difference?
>
> On the automobile engine, when we turn off the engine, are we just
> closing the switch that provides current to the spark plugs, or is
> something else involved? Is this what should be done for the aircraft
> engine?
>
> Thanks for your advice.
>
> Ken Johnson
>
>
>http://www.matronics.com/Navigator?AeroElectric-Listhttp://forums.matroni
cs.comhttp://www.matronics.com/contribution
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <nuckolls.bob(at)aeroelectric.com> |
| Subject: | Re: One or Two batteries with Single Alternator for |
Electric Airplane
At 08:50 AM 4/28/2010, you wrote:
>Bob,
>
>Which architecture should I be using for a VFR, day/night, single
>engine dual LSE ignition, single B&C 30 amp alternator and single
>MGL EFIS, radio, transponder, intercom?
>
>My emergency power draw would be 6.7 amps (cruise is 12.34 amps). I
>could use a single battery but would like to have a second smaller
>5-7 amp battery as a backup for the EFIS and one of the LSE ignitions.
Consider Z-13/8 with one 17 a.h. battery. Does
B&C offer a 30A alternator? LSE recommends two
batteries for two ignitions. It's a higher cost
of ownership and heavier system but it will perform
as advertised.
Bob . . .
////
(o o)
===========o00o=(_)=o00o========
< Go ahead, make my day . . . >
< show me where I'm wrong. >
================================
________________________________________________________________________________
| From: | Charlie England <ceengland(at)bellsouth.net> |
| Subject: | Re: stopping engine |
A couple of thoughts.
With electronic automotive injection, killing the injector power will
stop the injectors, but the fuel rail will still be pressurized. If an
injector is a bit leaky, fuel can still make it to the combustion
chamber after shutdown. Some guys provide a tiny bleed hole that
bypasses the regulator so the fuel rail will depressurize a minute or so
after shutdown (probably overkill, but there it is).
On the subject of traditional a/c engines with carbs, there is a
possible misconception buried below (I hate RPN posting....). I read
about the following somewhere & was surprised, but cutaway drawings of
some a/c carbs seem to support the story. I believe that the McNeilly
(sp?) leaning block for Holley carbs works this way, too, and the
technique has been used to lean some motorcycle carbs on alternative
engines. Here's the 'story':
On at least some a/c carbs, the mixture control is actually controlling
the vent to the fuel bowl on the carb. Pulling mixture to idle cutoff on
those carbs just causes the 'head' (air pressure+fuel weight) on the
fuel in the bowl to drop until it equals the absolute pressure in the
venturi, stopping flow. Once the engine stops, pressure can equalize at
ambient. If the prop spins after that happens, and the mags are on, the
engine can fire because there's still fuel available & there's now a
(short term) normal 'head' of ambient pressure on the fuel in the bowl.
Charlie
On 4/28/2010 11:32 AM, Mike Fontenot wrote:
> I have a GEO engine, EFI is the EC2 system, with 2 fuel pumps going
> into a single line, then to the fuel rail. In that line is a 3 way
> valve that I can use to bypass the rail and spill back into the fuel
> tank. Turning off the engine by starving the fuel, yet keeping the
> pumps running smoothly works quite well.
>
> On Wed, Apr 28, 2010 at 10:11 AM, Kenneth Johnson
> > wrote:
>
> Hi All,
> I would like to thank all who responded.
> It would seem the best reason to stop an engine with fuel
> starvation would be to prevent possible danger from the prop. If
> a prop was repositioned, fuel in a cylinder might ignite, which in
> turn would turn the prop and that might hurt someone. In an
> automobile, if dieseling occurs, no is hurt. The car is in "Park"
> or "Neutral."
> I have a Mazda rotary engine I will be using for my airplane.
> Eventhough this is not a piston engine, the threat of danger from
> the prop with fuel left in the burn chamber still exists. For
> safety reasons, fuel starvation would be the best way to stop the
> engine. Turning off the ignition will stop current to the spark
> plugs, coils, and will turn off the high pressure fuel pump.
> However, it would seem that turning off the fuel pump before
> turning off the ignition would be a safer way to eliminate fuel
> from the burn chambers.
> By using a valve on my fuel rail, I could stop fuel. However, the
> fuel pump would still be working and could be damaged. Again, it
> would seem that switching off the fuel pump before the
> ignition might be the best solution.
> If anyone has a better solution, please post.
> Thanks,
> Ken Johnson
>
> ------------------------------------------------------------------------
> *From:* Matt Prather >
> *To:* aeroelectric-list(at)matronics.com
>
> *Sent:* Tue, April 27, 2010 1:54:43 PM
> *Subject:* RE: AeroElectric-List: stopping engine
>
> >
>
> I think it's worthwhile to be precise (reduce ambiguity) in
> matters such
> as this.
>
> I believe many (most?) light airplane POH's specify that engine
> shutdown
> is accomplished by moving the mixture control to idle-cutoff (ICO).
> Usually this causes the engine to stop running fairly rapidly - in a
> matter of a couple of seconds. Selecting rich mixture and hitting the
> starter usually allows the engine to restart very quickly/easily.
>
> Certainly many airplanes still have Stromberg carbs (or similar) which
> don't have a mixture control effective enough to cause
> "idle-cutoff". I
> have ridden with pilots of such airplanes who only use the magneto
> switches to stop the engine. One benefit of this procedure is
> that you
> check to see if you have a "hot mag" on each flight. If the
> engine stops
> dead, you can be somewhat certain that the p-lead circuit is in
> working
> condition.
>
> Most (all?) light airplanes also have at least one fuel control valve
> (selector), which can also be used to stop the flow of fuel to the
> engine.
> On the carbureted engines that I have operated, closing this fuel
> valve
> does eventually stop the engine, though depending on how low the
> throttle
> setting is, it might take a few minutes for the float bowl in the
> carb to
> get low enough to cause the engine to lean-out and die. Usually
> when I
> pull up to a parking spot, I don't feel like waiting for the carb to
> empty, so I never do this.
>
> If the fuel valve was turned off, on carbureted airplanes with gravity
> feed fuel, turning on the fuel valve and waiting a few moments
> will refill
> the carb float bowl, at which point the engine may be restarted.
> For an
> airplane with pump driven fuel, turning on the electric pump will
> allow
> restarting much faster/sooner than if only the engine driven pump
> is used.
> Turning on the electric pump is often in the engine start procedure.
>
> In an airplane that depends on a high pressure electric pump, I'm
> not sure
> it makes sense to "turn off the fuel," if that implies closing
> some kind
> of fuel valve. It might make more sense to turn off the electric
> pump(s).
>
> My impression of automotive fuel injection is that turning the key off
> stops power to both the ignition and the fuel pump(s). This leaves
> burnable mixture in the cylinders and intake manifold. In an
> airplane,
> this method of stopping the engine increases the risk of
> unexpected prop
> motion. Turning the key to run causes the fuel pump(s) to run
> until the
> specified system pressure is reached, at which point the pump(s)
> turn off.
>
> One other thing I have noticed is that some electronic ignition
> systems
> may fire the spark plugs one time when the system is energized.
> This will
> likely cause the prop to turn if there is a burnable mixture in the
> cylinders. In fact, my Varieze has such a system. A number of
> times I
> have actually had the engine start spontaneously because of this
> effect -
> prime with accelerator pump, walk the prop to pull fuel into the
> cylinders, turn on the ignition, and away it goes. So, magnetos
> aren't
> the only things that will fire unexpectedly. In fact, a mag
> without an
> impulse couple isn't likely going to spark on its own..
>
> So to get back to the original question, I agree that stopping
> the fuel
> delivery in some way is generally a good idea. I think turning
> off the
> pumps while leaving the ignition firing is the best bet, as that
> should
> dump fuel system pressure, and yield the least burnable mixture in the
> cylinders.
>
> With all that said, everyone working around aircraft should be very
> careful of the propeller, whatever method is used to stop the engine.
> Pilots need to be vigilant to not allow anyone to haphazardly move the
> prop or stand in the prop arc.
>
>
> Regards,
>
> Matt-
>
> > In an Aviation carbed or injected engine, the shutoff method is the
> > same- turn off the fuel. The reason for this is to prevent a
> fuel/air
> > mixture being left in a cylinder. If a P lead wire is broken and the
> > propeller is turned, it could fire and injure someone. From your
> > question I assume youre installing an auto engine.
> >
> > Auto engines kill the spark. Some might also kill the pressure
> in the
> > fuel rail. Youre going to have to blas your own trail here.
> >
> > Bruce
> > www.Glasair.org <http://www.glasair.org/>
> > -----Original Message-----
> > From: owner-aeroelectric-list-server(at)matronics.com
>
> > [mailto:owner-aeroelectric-list-server(at)matronics.com
> ] On Behalf Of
> > Kenneth Johnson
> > Sent: Tuesday, April 27, 2010 12:45 PM
> > To: aeroelectric-list(at)matronics.com
>
> > Subject: AeroElectric-List: stopping engine
> >
> > Aircraft Electrical Gurus,
> > This subject has been presented briefly recently, but I was
> looking for
> > the opinion of several. This may have an electrical solution of
> not.
> > The question is: "What is the best way to stop your aircraft engine?
> >
> > In the recent past, at this site I have seen recommended a
> switch to the
> > fuel pump. Turn off the fuel pump and eventually the engine stops.
> >
> > I rent Cessna 172 and the prefered way to stop the engine is to
> minimize
> > both the throttle and richness knobs by pulling them out.
> Technically,
> > what exactly does this do? Could I place a simple ball valve on
> my fuel
> > rail and phsically close it? Is this what I do on the Cessna
> 172? The
> > Cessna fuel is fed throught a carburetor and my engine is fuel
> injected.
> > Does that make a difference?
> >
> > On the automobile engine, when we turn off the engine, are we just
> > closing the switch that provides current to the spark plugs, or is
> > something else involved? Is this what should be done for the
> aircraft
> > engine?
> >
> > Thanks for your advice.
> >
> > Ken Johnson
> >
> >
> >
> >
>
>
> *
>
> ist" target="_blank">http://www.matronics.com/Navigator?AeroElectric-List
> tp://forums.matronics.com
> _blank">http://www.matronics.com/contribution
>
> *
>
>
> --
> Mike
>
> ===============================
> Mike Fontenot
> Apex Consulting & Services LLC
> Lakewood, Colorado
> 303 / 731-6645
> mikef AT apexconsultingservices DOT com
> ======
> *
>
>
> *
________________________________________________________________________________
| From: | "Bill Bradburry" <bbradburry(at)bellsouth.net> |
Matt,
One other consideration about the Mazda rotary vs a typical piston airplane
engine is the blade rotation involved. If either whacked you in the head,
you would probably not be real happy about it. However...
The 4 cycle piston engine will rotate the prop 180 degrees on one power
stroke, but the rotary will only rotate the crankshaft 120 degrees if all
three rotor faces fire and only 40 degrees if one face fires. Since the
rotary has a PSRU on it which is probably either 2.17 or 2.85 to 1, this
would further reduce the prop movement to 18.5 to 14 degrees depending on
which PSRU.
The rotary would give you a good whack, but you would have to be standing
close to the blade for it to hit you.
Bill B
-----Original Message-----
From: owner-aeroelectric-list-server(at)matronics.com
[mailto:owner-aeroelectric-list-server(at)matronics.com] On Behalf Of Matt
Prather
Sent: Wednesday, April 28, 2010 2:04 PM
Subject: RE: AeroElectric-List: stopping engine
Bill,
My only concern about this (and it's probably a remote concern) is that if
you have a leaking injector, it may dribble fuel into the engine after
shutdown. Otherwise, this is very much analogous to pulling the mixture
to ICO on an aircraft carb or mechanical injection.
Matt-
> Ken,
>
> You didnt say if you have fuel injection or a carb on your Mazda rotary,
> but if you have FI, you can shut off the injectors and the engine will
> immediately stop due to fuel starvation. No fuel will be left in the
> rotor
> faces. The fuel regulator will then immediately open up to keep the fuel
> pressure at your set point, so the fuel pumps will not be adversely
> affected. In fact, this is the condition you will have the regulator and
> pumps in when you set the fuel pressure. This is the way it is designed
> to
> work so no damage will ensue. After the engine stops you can leisurely
> shut
> everything else down. There will be no fuel in the rotors so there will
> be
> no danger if you want to move the prop for whatever reason.
>
> If you have a carb, well, you are on your own.. :>)
>
>
> Bill B
>
>
> _____
>
> From: owner-aeroelectric-list-server(at)matronics.com
> [mailto:owner-aeroelectric-list-server(at)matronics.com] On Behalf Of Kenneth
> Johnson
> Sent: Wednesday, April 28, 2010 12:11 PM
> To: aeroelectric-list(at)matronics.com
> Subject: Re: AeroElectric-List: stopping engine
>
>
> Hi All,
>
> I would like to thank all who responded.
>
>
> It would seem the best reason to stop an engine with fuel starvation would
> be to prevent possible danger from the prop. If a prop was repositioned,
> fuel in a cylinder might ignite, which in turn would turn the prop and
> that
> might hurt someone. In an automobile, if dieseling occurs, no is hurt.
> The
> car is in "Park" or "Neutral."
>
>
> I have a Mazda rotary engine I will be using for my airplane. Eventhough
> this is not a piston engine, the threat of danger from the prop with fuel
> left in the burn chamber still exists. For safety reasons, fuel
> starvation
> would be the best way to stop the engine. Turning off the ignition will
> stop current to the spark plugs, coils, and will turn off the high
> pressure
> fuel pump. However, it would seem that turning off the fuel pump before
> turning off the ignition would be a safer way to eliminate fuel from the
> burn chambers.
>
>
> By using a valve on my fuel rail, I could stop fuel. However, the fuel
> pump
> would still be working and could be damaged. Again, it would seem that
> switching off the fuel pump before the ignition might be the best
> solution.
>
>
> If anyone has a better solution, please post.
>
>
> Thanks,
>
>
> Ken Johnson
>
>
> _____
>
> From: Matt Prather <mprather(at)spro.net>
> To: aeroelectric-list(at)matronics.com
> Sent: Tue, April 27, 2010 1:54:43 PM
> Subject: RE: AeroElectric-List: stopping engine
>
>
>
> I think it's worthwhile to be precise (reduce ambiguity) in matters such
> as this.
>
> I believe many (most?) light airplane POH's specify that engine shutdown
> is accomplished by moving the mixture control to idle-cutoff (ICO).
> Usually this causes the engine to stop running fairly rapidly - in a
> matter of a couple of seconds. Selecting rich mixture and hitting the
> starter usually allows the engine to restart very quickly/easily.
>
> Certainly many airplanes still have Stromberg carbs (or similar) which
> don't have a mixture control effective enough to cause "idle-cutoff". I
> have ridden with pilots of such airplanes who only use the magneto
> switches to stop the engine. One benefit of this procedure is that you
> check to see if you have a "hot mag" on each flight. If the engine stops
> dead, you can be somewhat certain that the p-lead circuit is in working
> condition.
>
> Most (all?) light airplanes also have at least one fuel control valve
> (selector), which can also be used to stop the flow of fuel to the engine.
> On the carbureted engines that I have operated, closing this fuel valve
> does eventually stop the engine, though depending on how low the throttle
> setting is, it might take a few minutes for the float bowl in the carb to
> get low enough to cause the engine to lean-out and die. Usually when I
> pull up to a parking spot, I don't feel like waiting for the carb to
> empty, so I never do this.
>
> If the fuel valve was turned off, on carbureted airplanes with gravity
> feed fuel, turning on the fuel valve and waiting a few moments will refill
> the carb float bowl, at which point the engine may be restarted. For an
> airplane with pump driven fuel, turning on the electric pump will allow
> restarting much faster/sooner than if only the engine driven pump is used.
> Turning on the electric pump is often in the engine start procedure.
>
> In an airplane that depends on a high pressure electric pump, I'm not sure
> it makes sense to "turn off the fuel," if that implies closing some kind
> of fuel valve. It might make more sense to turn off the electric pump(s).
>
> My impression of automotive fuel injection is that turning the key off
> stops power to both the ignition and the fuel pump(s). This leaves
> burnable mixture in the cylinders and intake manifold. In an airplane,
> this method of stopping the engine increases the risk of unexpected prop
> motion. Turning the key to run causes the fuel pump(s) to run until the
> specified system pressure is reached, at which point the pump(s) turn off.
>
> One other thing I have noticed is that some electronic ignition systems
> may fire the spark plugs one time when the system is energized. This will
> likely cause the prop to turn if there is a burnable mixture in the
> cylinders. In fact, my Varieze has such a system. A number of times I
> have actually had the engine start spontaneously because of this effect -
> prime with accelerator pump, walk the prop to pull fuel into the
> cylinders, turn on the ignition, and away it goes. So, magnetos aren't
> the only things that will fire unexpectedly. In fact, a mag without an
> impulse couple isn't likely going to spark on its own..
>
> So to get back to the original question, I agree that stopping the fuel
> delivery in some way is generally a good idea. I think turning off the
> pumps while leaving the ignition firing is the best bet, as that should
> dump fuel system pressure, and yield the least burnable mixture in the
> cylinders.
>
> With all that said, everyone working around aircraft should be very
> careful of the propeller, whatever method is used to stop the engine.
> Pilots need to be vigilant to not allow anyone to haphazardly move the
> prop or stand in the prop arc.
>
>
> Regards,
>
> Matt-
>
>> In an Aviation carbed or injected engine, the shutoff method is the
>> same- turn off the fuel. The reason for this is to prevent a fuel/air
>> mixture being left in a cylinder. If a P lead wire is broken and the
>> propeller is turned, it could fire and injure someone. From your
>> question I assume youre installing an auto engine.
>>
>> Auto engines kill the spark. Some might also kill the pressure in the
>> fuel rail. Youre going to have to blas your own trail here.
>>
>> Bruce
>> www.Glasair.org <http://www.glasair.org/>
>> -----Original Message-----
>> From: owner-aeroelectric-list-server(at)matronics.com
>> [mailto:owner-aeroelectric-list-server(at)matronics.com] On Behalf Of
>> Kenneth Johnson
>> Sent: Tuesday, April 27, 2010 12:45 PM
>> To: aeroelectric-list(at)matronics.com
>> Subject: AeroElectric-List: stopping engine
>>
>> Aircraft Electrical Gurus,
>> This subject has been presented briefly recently, but I was looking for
>> the opinion of several. This may have an electrical solution of not.
>> The question is: "What is the best way to stop your aircraft engine?
>>
>> In the recent past, at this site I have seen recommended a switch to the
>> fuel pump. Turn off the fuel pump and eventually the engine stops.
>>
>> I rent Cessna 172 and the prefered way to stop the engine is to minimize
>> both the throttle and richness knobs by pulling them out. Technically,
>> what exactly does this do? Could I place a simple ball valve on my fuel
>> rail and phsically close it? Is this what I do on the Cessna 172? The
>> Cessna fuel is fed throught a carburetor and my engine is fuel injected.
>> Does that make a difference?
>>
>> On the automobile engine, when we turn off the engine, are we just
>> closing the switch that provides current to the spark plugs, or is
>> something else involved? Is this what should be done for the aircraft
>> engine?
>>
>> Thanks for your advice.
>>
>> Ken Johnson
>>
>>
>>
>>
>
________________________________________________________________________________
| From: | "Bill Bradburry" <bbradburry(at)bellsouth.net> |
Matt,
An injector with much of a leak will show up on the way the engine performs,
but some have installed a small orifice (.050") in a bypass line around the
fuel pressure regulator. This small leak is not more than the pump and
regulator can handle, but when the pump is turned off, the line pressure
quickly bleeds off into the tank return line. This would stop any possible
problems from a leaky injector.
Bill B
-----Original Message-----
From: owner-aeroelectric-list-server(at)matronics.com
[mailto:owner-aeroelectric-list-server(at)matronics.com] On Behalf Of Matt
Prather
Sent: Wednesday, April 28, 2010 2:04 PM
Subject: RE: AeroElectric-List: stopping engine
Bill,
My only concern about this (and it's probably a remote concern) is that if
you have a leaking injector, it may dribble fuel into the engine after
shutdown. Otherwise, this is very much analogous to pulling the mixture
to ICO on an aircraft carb or mechanical injection.
Matt-
> Ken,
>
> You didnt say if you have fuel injection or a carb on your Mazda rotary,
> but if you have FI, you can shut off the injectors and the engine will
> immediately stop due to fuel starvation. No fuel will be left in the
> rotor
> faces. The fuel regulator will then immediately open up to keep the fuel
> pressure at your set point, so the fuel pumps will not be adversely
> affected. In fact, this is the condition you will have the regulator and
> pumps in when you set the fuel pressure. This is the way it is designed
> to
> work so no damage will ensue. After the engine stops you can leisurely
> shut
> everything else down. There will be no fuel in the rotors so there will
> be
> no danger if you want to move the prop for whatever reason.
>
> If you have a carb, well, you are on your own.. :>)
>
>
> Bill B
>
>
> _____
>
> From: owner-aeroelectric-list-server(at)matronics.com
> [mailto:owner-aeroelectric-list-server(at)matronics.com] On Behalf Of Kenneth
> Johnson
> Sent: Wednesday, April 28, 2010 12:11 PM
> To: aeroelectric-list(at)matronics.com
> Subject: Re: AeroElectric-List: stopping engine
>
>
> Hi All,
>
> I would like to thank all who responded.
>
>
> It would seem the best reason to stop an engine with fuel starvation would
> be to prevent possible danger from the prop. If a prop was repositioned,
> fuel in a cylinder might ignite, which in turn would turn the prop and
> that
> might hurt someone. In an automobile, if dieseling occurs, no is hurt.
> The
> car is in "Park" or "Neutral."
>
>
> I have a Mazda rotary engine I will be using for my airplane. Eventhough
> this is not a piston engine, the threat of danger from the prop with fuel
> left in the burn chamber still exists. For safety reasons, fuel
> starvation
> would be the best way to stop the engine. Turning off the ignition will
> stop current to the spark plugs, coils, and will turn off the high
> pressure
> fuel pump. However, it would seem that turning off the fuel pump before
> turning off the ignition would be a safer way to eliminate fuel from the
> burn chambers.
>
>
> By using a valve on my fuel rail, I could stop fuel. However, the fuel
> pump
> would still be working and could be damaged. Again, it would seem that
> switching off the fuel pump before the ignition might be the best
> solution.
>
>
> If anyone has a better solution, please post.
>
>
> Thanks,
>
>
> Ken Johnson
>
>
> _____
>
> From: Matt Prather <mprather(at)spro.net>
> To: aeroelectric-list(at)matronics.com
> Sent: Tue, April 27, 2010 1:54:43 PM
> Subject: RE: AeroElectric-List: stopping engine
>
>
>
> I think it's worthwhile to be precise (reduce ambiguity) in matters such
> as this.
>
> I believe many (most?) light airplane POH's specify that engine shutdown
> is accomplished by moving the mixture control to idle-cutoff (ICO).
> Usually this causes the engine to stop running fairly rapidly - in a
> matter of a couple of seconds. Selecting rich mixture and hitting the
> starter usually allows the engine to restart very quickly/easily.
>
> Certainly many airplanes still have Stromberg carbs (or similar) which
> don't have a mixture control effective enough to cause "idle-cutoff". I
> have ridden with pilots of such airplanes who only use the magneto
> switches to stop the engine. One benefit of this procedure is that you
> check to see if you have a "hot mag" on each flight. If the engine stops
> dead, you can be somewhat certain that the p-lead circuit is in working
> condition.
>
> Most (all?) light airplanes also have at least one fuel control valve
> (selector), which can also be used to stop the flow of fuel to the engine.
> On the carbureted engines that I have operated, closing this fuel valve
> does eventually stop the engine, though depending on how low the throttle
> setting is, it might take a few minutes for the float bowl in the carb to
> get low enough to cause the engine to lean-out and die. Usually when I
> pull up to a parking spot, I don't feel like waiting for the carb to
> empty, so I never do this.
>
> If the fuel valve was turned off, on carbureted airplanes with gravity
> feed fuel, turning on the fuel valve and waiting a few moments will refill
> the carb float bowl, at which point the engine may be restarted. For an
> airplane with pump driven fuel, turning on the electric pump will allow
> restarting much faster/sooner than if only the engine driven pump is used.
> Turning on the electric pump is often in the engine start procedure.
>
> In an airplane that depends on a high pressure electric pump, I'm not sure
> it makes sense to "turn off the fuel," if that implies closing some kind
> of fuel valve. It might make more sense to turn off the electric pump(s).
>
> My impression of automotive fuel injection is that turning the key off
> stops power to both the ignition and the fuel pump(s). This leaves
> burnable mixture in the cylinders and intake manifold. In an airplane,
> this method of stopping the engine increases the risk of unexpected prop
> motion. Turning the key to run causes the fuel pump(s) to run until the
> specified system pressure is reached, at which point the pump(s) turn off.
>
> One other thing I have noticed is that some electronic ignition systems
> may fire the spark plugs one time when the system is energized. This will
> likely cause the prop to turn if there is a burnable mixture in the
> cylinders. In fact, my Varieze has such a system. A number of times I
> have actually had the engine start spontaneously because of this effect -
> prime with accelerator pump, walk the prop to pull fuel into the
> cylinders, turn on the ignition, and away it goes. So, magnetos aren't
> the only things that will fire unexpectedly. In fact, a mag without an
> impulse couple isn't likely going to spark on its own..
>
> So to get back to the original question, I agree that stopping the fuel
> delivery in some way is generally a good idea. I think turning off the
> pumps while leaving the ignition firing is the best bet, as that should
> dump fuel system pressure, and yield the least burnable mixture in the
> cylinders.
>
> With all that said, everyone working around aircraft should be very
> careful of the propeller, whatever method is used to stop the engine.
> Pilots need to be vigilant to not allow anyone to haphazardly move the
> prop or stand in the prop arc.
>
>
> Regards,
>
> Matt-
>
>> In an Aviation carbed or injected engine, the shutoff method is the
>> same- turn off the fuel. The reason for this is to prevent a fuel/air
>> mixture being left in a cylinder. If a P lead wire is broken and the
>> propeller is turned, it could fire and injure someone. From your
>> question I assume youre installing an auto engine.
>>
>> Auto engines kill the spark. Some might also kill the pressure in the
>> fuel rail. Youre going to have to blas your own trail here.
>>
>> Bruce
>> www.Glasair.org <http://www.glasair.org/>
>> -----Original Message-----
>> From: owner-aeroelectric-list-server(at)matronics.com
>> [mailto:owner-aeroelectric-list-server(at)matronics.com] On Behalf Of
>> Kenneth Johnson
>> Sent: Tuesday, April 27, 2010 12:45 PM
>> To: aeroelectric-list(at)matronics.com
>> Subject: AeroElectric-List: stopping engine
>>
>> Aircraft Electrical Gurus,
>> This subject has been presented briefly recently, but I was looking for
>> the opinion of several. This may have an electrical solution of not.
>> The question is: "What is the best way to stop your aircraft engine?
>>
>> In the recent past, at this site I have seen recommended a switch to the
>> fuel pump. Turn off the fuel pump and eventually the engine stops.
>>
>> I rent Cessna 172 and the prefered way to stop the engine is to minimize
>> both the throttle and richness knobs by pulling them out. Technically,
>> what exactly does this do? Could I place a simple ball valve on my fuel
>> rail and phsically close it? Is this what I do on the Cessna 172? The
>> Cessna fuel is fed throught a carburetor and my engine is fuel injected.
>> Does that make a difference?
>>
>> On the automobile engine, when we turn off the engine, are we just
>> closing the switch that provides current to the spark plugs, or is
>> something else involved? Is this what should be done for the aircraft
>> engine?
>>
>> Thanks for your advice.
>>
>> Ken Johnson
>>
>>
>>
>>
>
________________________________________________________________________________
| From: | "Ed Anderson" <eanderson(at)carolina.rr.com> |
Ken, you didn=92t say,
But if you are using electronic fuel injectors with your rotary engine,
a
power cut off switch to the injectors will instantly stop injection even
with your pumps still running. That is the method I use for shut down
and
there is no fuel left in combustion chamber nor any potential to damage
the
fuel pumps by running them dry.
http://www.flyrotary.com/
You may want to consider joining our FlyRotary list ' there are many
flying
who have solved most problems you are likely to encounter and the
information is there.
Ed
Ed Anderson
Rv-6A N494BW Rotary Powered
Matthews, NC
eanderson(at)carolina.rr.com
<http://www.andersonee.com> http://www.andersonee.com
<http://www.dmack.net/mazda/index.html>
http://www.dmack.net/mazda/index.html
http://www.flyrotary.com/
<http://members.cox.net/rogersda/rotary/configs.htm>
http://members.cox.net/rogersda/rotary/configs.htm#N494BW
http://www.rotaryaviation.com/Rotorhead%20Truth.htm
<http://www.dmack.net/mazda/index.html>
_____
From: owner-aeroelectric-list-server(at)matronics.com
[mailto:owner-aeroelectric-list-server(at)matronics.com] On Behalf Of
Kenneth
Johnson
Sent: Wednesday, April 28, 2010 12:11 PM
Subject: Re: AeroElectric-List: stopping engine
Hi All,
I would like to thank all who responded.
It would seem the best reason to stop an engine with fuel starvation
would
be to prevent possible danger from the prop. If a prop was
repositioned,
fuel in a cylinder might ignite, which in turn would turn the prop and
that
might hurt someone. In an automobile, if dieseling occurs, no is hurt.
The
car is in "Park" or "Neutral."
I have a Mazda rotary engine I will be using for my airplane.
Eventhough
this is not a piston engine, the threat of danger from the prop with
fuel
left in the burn chamber still exists. For safety reasons, fuel
starvation
would be the best way to stop the engine. Turning off the ignition will
stop current to the spark plugs, coils, and will turn off the high
pressure
fuel pump. However, it would seem that turning off the fuel pump before
turning off the ignition would be a safer way to eliminate fuel from the
burn chambers.
By using a valve on my fuel rail, I could stop fuel. However, the fuel
pump
would still be working and could be damaged. Again, it would seem that
switching off the fuel pump before the ignition might be the best
solution.
If anyone has a better solution, please post.
Thanks,
Ken Johnson
_____
From: Matt Prather <mprather(at)spro.net>
Sent: Tue, April 27, 2010 1:54:43 PM
Subject: RE: AeroElectric-List: stopping engine
I think it's worthwhile to be precise (reduce ambiguity) in matters such
as this.
I believe many (most?) light airplane POH's specify that engine shutdown
is accomplished by moving the mixture control to idle-cutoff (ICO).
Usually this causes the engine to stop running fairly rapidly - in a
matter of a couple of seconds. Selecting rich mixture and hitting the
starter usually allows the engine to restart very quickly/easily.
Certainly many airplanes still have Stromberg carbs (or similar) which
don't have a mixture control effective enough to cause "idle-cutoff". I
have ridden with pilots of such airplanes who only use the magneto
switches to stop the engine. One benefit of this procedure is that you
check to see if you have a "hot mag" on each flight. If the engine
stops
dead, you can be somewhat certain that the p-lead circuit is in working
condition.
Most (all?) light airplanes also have at least one fuel control valve
(selector), which can also be used to stop the flow of fuel to the
engine.
On the carbureted engines that I have operated, closing this fuel valve
does eventually stop the engine, though depending on how low the
throttle
setting is, it might take a few minutes for the float bowl in the carb
to
get low enough to cause the engine to lean-out and die. Usually when I
pull up to a parking spot, I don't feel like waiting for the carb to
empty, so I never do this.
If the fuel valve was turned off, on carbureted airplanes with gravity
feed fuel, turning on the fuel valve and waiting a few moments will
refill
the carb float bowl, at which point the engine may be restarted. For an
airplane with pump driven fuel, turning on the electric pump will allow
restarting much faster/sooner than if only the engine driven pump is
used.
Turning on the electric pump is often in the engine start procedure.
In an airplane that depends on a high pressure electric pump, I'm not
sure
it makes sense to "turn off the fuel," if that implies closing some kind
of fuel valve. It might make more sense to turn off the electric
pump(s).
My impression of automotive fuel injection is that turning the key off
stops power to both the ignition and the fuel pump(s). This leaves
burnable mixture in the cylinders and intake manifold. In an airplane,
this method of stopping the engine increases the risk of unexpected prop
motion. Turning the key to run causes the fuel pump(s) to run until the
specified system pressure is reached, at which point the pump(s) turn
off.
One other thing I have noticed is that some electronic ignition systems
may fire the spark plugs one time when the system is energized. This
will
likely cause the prop to turn if there is a burnable mixture in the
cylinders. In fact, my Varieze has such a system. A number of times I
have actually had the engine start spontaneously because of this effect
-
prime with accelerator pump, walk the prop to pull fuel into the
cylinders, turn on the ignition, and away it goes. So, magnetos aren't
the only things that will fire unexpectedly. In fact, a mag without an
impulse couple isn't likely going to spark on its own..
So to get back to the original question, I agree that stopping the fuel
delivery in some way is generally a good idea. I think turning off the
pumps while leaving the ignition firing is the best bet, as that should
dump fuel system pressure, and yield the least burnable mixture in the
cylinders.
With all that said, everyone working around aircraft should be very
careful of the propeller, whatever method is used to stop the engine.
Pilots need to be vigilant to not allow anyone to haphazardly move the
prop or stand in the prop arc.
Regards,
Matt-
> In an Aviation carb=92ed or injected engine, the shutoff method is the
> same- turn off the fuel. The reason for this is to prevent a fuel/air
> mixture being left in a cylinder. If a P lead wire is broken and the
> propeller is turned, it could fire and injure someone. From your
> question I assume you=92re installing an auto engine.
>
> Auto engines kill the spark. Some might also kill the pressure in the
> fuel rail. You=92re going to have to blas=E9 your own trail here.
>
> Bruce
> www.Glasair.org <http://www.glasair.org/>
> -----Original Message-----
> From: owner-aeroelectric-list-server(at)matronics.com
> [mailto:owner-aeroelectric-list-server(at)matronics.com] On Behalf Of
> Kenneth Johnson
> Sent: Tuesday, April 27, 2010 12:45 PM
> To: aeroelectric-list(at)matronics.com
> Subject: AeroElectric-List: stopping engine
>
> Aircraft Electrical Gurus,
> This subject has been presented briefly recently, but I was looking
for
> the opinion of several. This may have an electrical solution of not.
> The question is: "What is the best way to stop your aircraft engine?
>
> In the recent past, at this site I have seen recommended a switch to
the
> fuel pump. Turn off the fuel pump and eventually the engine stops.
>
> I rent Cessna 172 and the prefered way to stop the engine is to
minimize
> both the throttle and richness knobs by pulling them out.
Technically,
> what exactly does this do? Could I place a simple ball valve on my
fuel
> rail and phsically close it? Is this what I do on the Cessna 172?
The
> Cessna fuel is fed throught a carburetor and my engine is fuel
injected.
> Does that make a difference?
>
> On the automobile engine, when we turn off the engine, are we just
> closing the switch that provides current to the spark plugs, or is
> something else involved? Is this what should be done for the aircraft
> engine?
>
> Thanks for your advice.
>
> Ken Johnson
>
>
>| Date: | Apr 29, 2010 |
| From: | "Robert L. Nuckolls, III" <nuckolls.bob(at)aeroelectric.com> |
| Subject: | IVO Prop Current Limiter/Electronic Circuit Breaker |
It took a bit more 'praying' than I anticipated
and I'm only 99.6% sure that my confidence in
having met design goals have been met. But I'll
invite other 'electron herders' on the List
to review the following and see if I've stubbed
my toe anywhere:
See:
http://aeroelectric.com/Pictures/Schematics/IVO-Prop_Pitch_Controller.pdf
Design goals:
Provide absolute current limit on the order of 9A:
Q114 is a power FET that saturates with bias
through R104, R105 and D109 when power is applied
through "M" connections that sense motor power.
Voltage drop across R117/R118 is monitored through
R116 causing Q115 to turn on when drop across the
R117/118 exceeds Vbe of Q115. This is approx .6
volts. When Q115 turns on, it starves Q114 of gate
drive and causes it to become a constant current
generator with calibration set by the combination
of R117/R118.
Any time the constant current loop is active,
LED D109 will be illuminated. D109 will flash
each time the prop pitch motor is energized
and the system becomes an active inrush current
limiter.
Limit the duration of the current limit mode to
100-200 mS whereupon the system goes open circuit
and removes power from the motor:
At any time the current limiter is active,
Q115 collector current through R105 will turn
on Q103 causing the collector to pull up to
the supply rail. This causes C112 to charge
through R106 until zener D110 conducts at about
8V. This event will occur approximately 120 mS
after onset of current limit.
When D110 conducts, it pulls the base of Q115
more positive causing the Q115/Q103 pair to
"latch up" not unlike an SCR. When the latching
event occurs, the collector of Q115 pulls to
a few millivolts above ground depriving Q114
of all gate drive.
Normal operation:
D109 will flash each time the motor control switch
is closed due to motor inrush current being
electronically limited. D109 will also flash a
bit longer (about 120 mS) when the prop pitch motor
reaches the mechanical stop and the current limit is
invoked.
As long as the prop pitch motor is powered
D108 will be illuminated. When the prop
pitch system reaches a mechanical limit and
the control switch is NOT relaxed, D019 flashes
for about 120 mS and D108 goes dark.
Releasing the motor control switch removes
power from the latching loop and discharges
C112 through R119, R104, BC junction Q103,
and R106.
The system spends so little time in I-limit
mode that Q114 does not require a heat-sink.
D109 and D108 staying on together indicates
a malfunction and the motor control switch
needs to be released within a second or so
to avoid over-heat damage to Q114.
Don't anyone run out and build this yet. Let's
thrash the bushes a bit for rats.
Bob . . .
________________________________________________________________________________
| Subject: | Re: stopping engine |
| From: | "Matt Prather" <mprather(at)spro.net> |
We're off in the weeds a bit as far as Aero Electrics..
I'm pretty sure that the Marvel Schebler carbs pass all of the fuel
through the main metering valve - even the idle circuit. Thus, pulling
the mixture to ICO on these units does, in fact, positively stop fuel
flow.
The Stromberg carbs, and those commonly installed on Rotax engines work as
you suggested. I believe these carbs are known variously as "altitude
compensating".
My impression of the Manual Mixture Control for the Holley is that it
works much like the Schebler - positively controlling fuel flow, not by
controlling venting of the float chamber. I could be mistaken here.
Regards,
Matt-
>
>
> A couple of thoughts.
>
> With electronic automotive injection, killing the injector power will
> stop the injectors, but the fuel rail will still be pressurized. If an
> injector is a bit leaky, fuel can still make it to the combustion
> chamber after shutdown. Some guys provide a tiny bleed hole that
> bypasses the regulator so the fuel rail will depressurize a minute or so
> after shutdown (probably overkill, but there it is).
>
> On the subject of traditional a/c engines with carbs, there is a
> possible misconception buried below (I hate RPN posting....). I read
> about the following somewhere & was surprised, but cutaway drawings of
> some a/c carbs seem to support the story. I believe that the McNeilly
> (sp?) leaning block for Holley carbs works this way, too, and the
> technique has been used to lean some motorcycle carbs on alternative
> engines. Here's the 'story':
>
> On at least some a/c carbs, the mixture control is actually controlling
> the vent to the fuel bowl on the carb. Pulling mixture to idle cutoff on
> those carbs just causes the 'head' (air pressure+fuel weight) on the
> fuel in the bowl to drop until it equals the absolute pressure in the
> venturi, stopping flow. Once the engine stops, pressure can equalize at
> ambient. If the prop spins after that happens, and the mags are on, the
> engine can fire because there's still fuel available & there's now a
> (short term) normal 'head' of ambient pressure on the fuel in the bowl.
>
> Charlie
>
________________________________________________________________________________
| From: | "n801bh(at)netzero.com" <n801bh(at)netzero.com> |
| Subject: | Re: stopping engine |
I will add a correction to the Mc Neilly mixture block for Holley carbs.
. Tom Mc Neilly designed the block to act like a variable main jet, not
to alter float bowl pressure... Some 2 and 4 stroke snowmobile motors u
se the bowl pressure method to trick the carb into thinking it is at a d
ifferent altitude..... Just for the record....
Ps... I LOVE my Mc Neilly mixture block on my V-8 powered experimental.
It works sooo good. !!!!!!
Ben Haas
N801BH
www.haaspowerair.com
---------- Original Message ----------
From: Charlie England <ceengland(at)bellsouth.net>
Subject: Re: AeroElectric-List: stopping engine
Date: Wed, 28 Apr 2010 16:01:12 -0500
south.net>
A couple of thoughts.
With electronic automotive injection, killing the injector power will
stop the injectors, but the fuel rail will still be pressurized. If an
injector is a bit leaky, fuel can still make it to the combustion
chamber after shutdown. Some guys provide a tiny bleed hole that
bypasses the regulator so the fuel rail will depressurize a minute or so
after shutdown (probably overkill, but there it is).
On the subject of traditional a/c engines with carbs, there is a
possible misconception buried below (I hate RPN posting....). I read
about the following somewhere & was surprised, but cutaway drawings of
some a/c carbs seem to support the story. I believe that the McNeilly
(sp?) leaning block for Holley carbs works this way, too, and the
technique has been used to lean some motorcycle carbs on alternative
engines. Here's the 'story':
On at least some a/c carbs, the mixture control is actually controlling
the vent to the fuel bowl on the carb. Pulling mixture to idle cutoff on
those carbs just causes the 'head' (air pressure+fuel weight) on the
fuel in the bowl to drop until it equals the absolute pressure in the
venturi, stopping flow. Once the engine stops, pressure can equalize at
ambient. If the prop spins after that happens, and the mags are on, the
engine can fire because there's still fuel available & there's now a
(short term) normal 'head' of ambient pressure on the fuel in the bowl.
Charlie
On 4/28/2010 11:32 AM, Mike Fontenot wrote:
> I have a GEO engine, EFI is the EC2 system, with 2 fuel pumps going
> into a single line, then to the fuel rail. In that line is a 3 way
> valve that I can use to bypass the rail and spill back into the fuel
> tank. Turning off the engine by starving the fuel, yet keeping the
> pumps running smoothly works quite well.
>
> On Wed, Apr 28, 2010 at 10:11 AM, Kenneth Johnson
> > wrote:
>
> Hi All,
> I would like to thank all who responded.
> It would seem the best reason to stop an engine with fuel
> starvation would be to prevent possible danger from the prop. If
> a prop was repositioned, fuel in a cylinder might ignite, which in
> turn would turn the prop and that might hurt someone. In an
> automobile, if dieseling occurs, no is hurt. The car is in "Park"
> or "Neutral."
> I have a Mazda rotary engine I will be using for my airplane.
> Eventhough this is not a piston engine, the threat of danger from
> the prop with fuel left in the burn chamber still exists. For
> safety reasons, fuel starvation would be the best way to stop the
> engine. Turning off the ignition will stop current to the spark
> plugs, coils, and will turn off the high pressure fuel pump.
> However, it would seem that turning off the fuel pump before
> turning off the ignition would be a safer way to eliminate fuel
> from the burn chambers.
> By using a valve on my fuel rail, I could stop fuel. However, the
> fuel pump would still be working and could be damaged. Again, it
> would seem that switching off the fuel pump before the
> ignition might be the best solution.
> If anyone has a better solution, please post.
> Thanks,
> Ken Johnson
>
> ------------------------------------------------------------------
------
> *From:* Matt Prather
>
> *To:* aeroelectric-list(at)matronics.com
>
> *Sent:* Tue, April 27, 2010 1:54:43 PM
> *Subject:* RE: AeroElectric-List: stopping engine
>
> >
>
> I think it's worthwhile to be precise (reduce ambiguity) in
> matters such
> as this.
>
> I believe many (most?) light airplane POH's specify that engine
> shutdown
> is accomplished by moving the mixture control to idle-cutoff (ICO)
.
> Usually this causes the engine to stop running fairly rapidly - in
a
> matter of a couple of seconds. Selecting rich mixture and hitting
the
> starter usually allows the engine to restart very quickly/easily.
>
> Certainly many airplanes still have Stromberg carbs (or similar) w
hich
> don't have a mixture control effective enough to cause
> "idle-cutoff". I
> have ridden with pilots of such airplanes who only use the magneto
> switches to stop the engine. One benefit of this procedure is
> that you
> check to see if you have a "hot mag" on each flight. If the
> engine stops
> dead, you can be somewhat certain that the p-lead circuit is in
> working
> condition.
>
> Most (all?) light airplanes also have at least one fuel control va
lve
> (selector), which can also be used to stop the flow of fuel to the
> engine.
> On the carbureted engines that I have operated, closing this fuel
> valve
> does eventually stop the engine, though depending on how low the
> throttle
> setting is, it might take a few minutes for the float bowl in the
> carb to
> get low enough to cause the engine to lean-out and die. Usually
> when I
> pull up to a parking spot, I don't feel like waiting for the carb
to
> empty, so I never do this.
>
> If the fuel valve was turned off, on carbureted airplanes with gra
vity
> feed fuel, turning on the fuel valve and waiting a few moments
> will refill
> the carb float bowl, at which point the engine may be restarted.
> For an
> airplane with pump driven fuel, turning on the electric pump will
> allow
> restarting much faster/sooner than if only the engine driven pump
> is used.
> Turning on the electric pump is often in the engine start procedur
e.
>
> In an airplane that depends on a high pressure electric pump, I'm
> not sure
> it makes sense to "turn off the fuel," if that implies closing
> some kind
> of fuel valve. It might make more sense to turn off the electric
> pump(s).
>
> My impression of automotive fuel injection is that turning the key
off
> stops power to both the ignition and the fuel pump(s). This leave
s
> burnable mixture in the cylinders and intake manifold. In an
> airplane,
> this method of stopping the engine increases the risk of
> unexpected prop
> motion. Turning the key to run causes the fuel pump(s) to run
> until the
> specified system pressure is reached, at which point the pump(s)
> turn off.
>
> One other thing I have noticed is that some electronic ignition
> systems
> may fire the spark plugs one time when the system is energized.
> This will
> likely cause the prop to turn if there is a burnable mixture in th
e
> cylinders. In fact, my Varieze has such a system. A number of
> times I
> have actually had the engine start spontaneously because of this
> effect -
> prime with accelerator pump, walk the prop to pull fuel into the
> cylinders, turn on the ignition, and away it goes. So, magnetos
> aren't
> the only things that will fire unexpectedly. In fact, a mag
> without an
> impulse couple isn't likely going to spark on its own..
>
> So to get back to the original question, I agree that stopping
> the fuel
> delivery in some way is generally a good idea. I think turning
> off the
> pumps while leaving the ignition firing is the best bet, as that
> should
> dump fuel system pressure, and yield the least burnable mixture in
the
> cylinders.
>
> With all that said, everyone working around aircraft should be ver
y
> careful of the propeller, whatever method is used to stop the engi
ne.
> Pilots need to be vigilant to not allow anyone to haphazardly move
the
> prop or stand in the prop arc.
>
>
> Regards,
>
> Matt-
>
> > In an Aviation carb=92ed or injected engine, the shutoff method
is the
> > same- turn off the fuel. The reason for this is to prevent a
> fuel/air
> > mixture being left in a cylinder. If a P lead wire is broken and
the
> > propeller is turned, it could fire and injure someone. From your
> > question I assume you=92re installing an auto engine.
> >
> > Auto engines kill the spark. Some might also kill the pressure
> in the
> > fuel rail. You=92re going to have to blas=E9 your own trail here
.
> >
> > Bruce
> > www.Glasair.org <http://www.glasair.org/>
> > -----Original Message-----
> > From: owner-aeroelectric-list-server(at)matronics.com
>
> > [mailto:owner-aeroelectric-list-server(at)matronics.com
> ] On Behalf O
f
> > Kenneth Johnson
> > Sent: Tuesday, April 27, 2010 12:45 PM
> > To: aeroelectric-list(at)matronics.com
>
> > Subject: AeroElectric-List: stopping engine
> >
> > Aircraft Electrical Gurus,
> > This subject has been presented briefly recently, but I was
> looking for
> > the opinion of several. This may have an electrical solution of
> not.
> > The question is: "What is the best way to stop your aircraft eng
ine?
> >
> > In the recent past, at this site I have seen recommended a
> switch to the
> > fuel pump. Turn off the fuel pump and eventually the engine sto
ps.
> >
> > I rent Cessna 172 and the prefered way to stop the engine is to
> minimize
> > both the throttle and richness knobs by pulling them out.
> Technically,
> > what exactly does this do? Could I place a simple ball valve on
> my fuel
> > rail and phsically close it? Is this what I do on the Cessna
> 172? The
> > Cessna fuel is fed throught a carburetor and my engine is fuel
> injected.
> > Does that make a difference?
> >
> > On the automobile engine, when we turn off the engine, are we ju
st
> > closing the switch that provides current to the spark plugs, or
is
> > something else involved? Is this what should be done for the
> aircraft
> > engine?
> >
> > Thanks for your advice.
> >
> > Ken Johnson
> >
> >
> >
> >
>
>
> *
>
> ist" target="_blank">http://www.matronics.com/Navigator?AeroElec
tric-List
> tp://forums.matronics.com
> _blank">http://www.matronics.com/contribution
>
> *
>
>
> --
> Mike
>
> ========================
=======
> Mike Fontenot
> Apex Consulting & Services LLC
> Lakewood, Colorado
> 303 / 731-6645
> mikef AT apexconsultingservices DOT com
> ======
> *
>
>
> *
========================
===========
========================
===========
========================
===========
========================
===========
____________________________________________________________
Penny Stock Jumping 2000%
Sign up to the #1 voted penny stock newsletter for free today!
http://thirdpartyoffers.netzero.net/TGL3241/4bd97ac096c4e1fcb6ast05vuc
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <nuckolls.bob(at)aeroelectric.com> |
| Subject: | Check out THIS structural test event |
A client of mine has some hardware on this airplane.
Suppliers to the program were alerted to a major milestone
in static testing for the airframe. See:
http://tinyurl.com/y5uqmpa
Bob . . .
________________________________________________________________________________
| Subject: | Re: Electrical diagram |
| From: | "user9253" <fran4sew(at)banyanol.com> |
Marc,
Your schematic is better than most type-certificated aircraft.
Having the start switch on the E-Bus is unusual. There is no advantage to having
it there because the engine will not start without the master contactor
being energized.
It is possible to leave the baggage light on and run the battery down.
I would consider putting the transponder and trim on the E-Bus. You could always
shut the transponder off if desired. The trim will not use power unless
the trim switch is pressed.
I assume that an EFIS will announce a low voltage condition. What about over-voltage
protection? Is that built into the alternator?
Joe
--------
Joe Gores
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=296274#296274
________________________________________________________________________________
| Subject: | Re: stopping engine |
| From: | "Eric M. Jones" <emjones(at)charter.net> |
In learning to fly in a C150/C172, the explanation was:
The fuel was gravity fed with a left-right- both selector (was there an OFF?),
the spark was magneto. In the event that the prop was turned by hand, the magneto
could start the engine if its P-lead to ground lead was defective. So throttle
at idle, mixture pulled lean until engine quit, switch off.
Your mileage may vary.
--------
Eric M. Jones
www.PerihelionDesign.com
113 Brentwood Drive
Southbridge, MA 01550
(508) 764-2072
emjones(at)charter.net
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=296286#296286
________________________________________________________________________________
| From: | Jared Yates <email(at)jaredyates.com> |
| Subject: | Mag switches in z13/8 |
I'm planning to use z13/8 in an airplane with mags at first, and
perhaps electronic ignition later. Would it be ok to copy the mag
switch arangement in z11, which uses the 2-5 switches?
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <nuckolls.bob(at)aeroelectric.com> |
| Subject: | Re: Mag switches in z13/8 |
At 09:05 AM 4/30/2010, you wrote:
>
>I'm planning to use z13/8 in an airplane with mags at first, and
>perhaps electronic ignition later. Would it be ok to copy the mag
>switch arangement in z11, which uses the 2-5 switches?
Sure. The 2-5 switches can be wired to accommodate
about any combination of mags and/or electronic
ignition switches.
Bob . . .
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <nuckolls.bob(at)aeroelectric.com> |
| Subject: | Re: Electrical diagram |
At 05:11 AM 4/30/2010, you wrote:
>
>Marc,
> Your schematic is better than most type-certificated aircraft.
> Having the start switch on the E-Bus is unusual. There is no
> advantage to having it there because the engine will not start
> without the master contactor being energized.
> It is possible to leave the baggage light on and run the battery down.
> I would consider putting the transponder and trim on the
> E-Bus. You could always shut the transponder off if desired. The
> trim will not use power unless the trim switch is pressed.
> I assume that an EFIS will announce a low voltage
> condition. What about over-voltage protection? Is that built into
> the alternator?
I'll second Joe's observations/questions. Additionally,
I'm curious as to a perceived advantage for not combining
alternator and battery master control in a single switch?
Are you planning on using the pullable breaker as the
means by which power is removed from the bus in flight?
Bob . . .
________________________________________________________________________________
| From: | "Glaeser, Dennis" <dennis.glaeser(at)hp.com> |
| Subject: | Re: IVO Prop Current Limiter/Electronic Circuit Breaker |
Bob,
The reed switch circuit is already in place and operational, so my initial goal
has been achieved!
I already have the parts for the first design - only half assembled at the moment
(having to work for a living gets in the way of the 'important stuff' :-)
The latest design literally dummy-proofs the operation of the IVO, and will undoubtedly
increase the MTBF of the motor and gearbox by limiting the motor electrically
rather than mechanically jamming the gears!
I can follow your description on how it works, but my knowledge falls short of
being able to analyze and comment. When you declare the updated circuit complete,
I'll build it (already have most of the components :-) and let you know how
it works!
It was me who was doing the 'praying' for a solution! You did the 'perspiration'
part - per Thomas Edison.
Thanks,
Dennis
-----------------------------------
From: Robert L. Nuckolls, III
It took a bit more 'praying' than I anticipated
and I'm only 99.6% sure that my confidence in
having met design goals have been met. But I'll
invite other 'electron herders' on the List
to review the following and see if I've stubbed
my toe anywhere:
See:
http://aeroelectric.com/Pictures/Schematics/IVO-Prop_Pitch_Controller.pdf
------------------------------------
________________________________________________________________________________
| From: | RGent1224(at)aol.com |
| Subject: | Re: IVO Prop Current Limiter/Electronic Circuit |
Breaker
Dennis
Do you have a circuit diagram/photos of your installation that you can
share??
Thanks
Dick
In a message dated 4/30/2010 11:44:48 A.M. Central Daylight Time,
dennis.glaeser(at)hp.com writes:
--> AeroElectric-List message posted by: "Glaeser, Dennis"
Bob,
The reed switch circuit is already in place and operational, so my initial
goal has been achieved!
I already have the parts for the first design - only half assembled at the
moment (having to work for a living gets in the way of the 'important
stuff' :-)
The latest design literally dummy-proofs the operation of the IVO, and
will undoubtedly increase the MTBF of the motor and gearbox by limiting the
motor electrically rather than mechanically jamming the gears!
I can follow your description on how it works, but my knowledge falls
short of being able to analyze and comment. When you declare the updated
circuit complete, I'll build it (already have most of the components :-) and let
you know how it works!
It was me who was doing the 'praying' for a solution! You did the
'perspiration' part - per Thomas Edison.
Thanks,
Dennis
-----------------------------------
From: Robert L. Nuckolls, III
It took a bit more 'praying' than I anticipated
and I'm only 99.6% sure that my confidence in
having met design goals have been met. But I'll
invite other 'electron herders' on the List
to review the following and see if I've stubbed
my toe anywhere:
See:
http://aeroelectric.com/Pictures/Schematics/IVO-Prop_Pitch_Controller.pdf
------------------------------------
________________________________________________________________________________
| Subject: | Re: Electrical diagram |
| From: | "marchudson" <marchudson(at)verizon.net> |
Bob and Joe, I want to thank you for reviewing my diagram. I appreciate it.
Have the start button on the e-bus was an oversight. I will move it to the main
bus. Thanks for catching that.
Leaving the baggage light on was taken into consideration and I'm willing to take
the risk on this one. I'm sure after if bites me a couple of times, I'll reconsider.
Joe, good call on putting the transponder and trim on e-bus. I will probably do
this as the transponder consumes little power.
The EFIS does annunciate a low voltage condition and crowbar over voltage protection
is built into the Plane Power alternator.
Bob, to be honest, I went with the single battery switch for simplicity and cost.
Much cheaper to purchase the two position locking Honeywell toggle than the
three position. Also, my thoughts were that I'm probably not going to be shutting
off the alternator that often. If I really need to then yes, I'm going
to be using the breaker as a switch. I called Plane Power twice and made sure
that this alternator will run fine without the battery online, just in case
the battery inadvertently got shut off with the engine running.
Again guys, I really appreciate you having a look.
Marc
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=296343#296343
________________________________________________________________________________
| From: | <bakerocb(at)cox.net> |
| Subject: | Electrical diagram |
5/1/2010
Hello Marc, You wrote: "Also, my thoughts were that I'm probably not going
to be shutting
off the alternator that often."
{Comment} My shut down procedure calls for shutting the externally regulated
alternator off (after confirming that the voltage and amperage being put out
is at a nominal level) and waiting for the low voltage light to start
flashing. This simulates an alternator failure in flight and confirms that
the low voltage warning system is working.
Then the engine is shut down with the mixture and the magnetos are turned
off.
Then ,after turning on the essential bus switch, the battery and avionics
master switch (yes, I have one) are turned off. This turns off all non
essential electrical and avionics items and is the procedure that I would
follow with an actual alternator failure in flight.
Then I confirm that the Garmin 430W and transponder are continuing to
operate, now from the avionics essential bus. These two boxes are required
for entering the Washington DC SFRA where I am based and for a reasonably
comfortable landing if operating elsewhere.
Then I shut off the essential bus switch and the shut down is complete.
'OC' Says: "The best investment we can make is the effort to gather and
understand knowledge."
========================================================
Subject: AeroElectric-List: Re: Electrical diagram
From: "marchudson" <marchudson(at)verizon.net>
Bob and Joe, I want to thank you for reviewing my diagram. I appreciate it.
Have the start button on the e-bus was an oversight. I will move it to the
main
bus. Thanks for catching that.
Leaving the baggage light on was taken into consideration and I'm willing to
take
the risk on this one. I'm sure after if bites me a couple of times, I'll
reconsider.
Joe, good call on putting the transponder and trim on e-bus. I will
probably do
this as the transponder consumes little power.
The EFIS does annunciate a low voltage condition and crowbar over voltage
protection
is built into the Plane Power alternator.
Bob, to be honest, I went with the single battery switch for simplicity and
cost.
Much cheaper to purchase the two position locking Honeywell toggle than the
three position. Also, my thoughts were that I'm probably not going to be
shutting
off the alternator that often. If I really need to then yes, I'm going
to be using the breaker as a switch. I called Plane Power twice and made
sure
that this alternator will run fine without the battery online, just in case
the battery inadvertently got shut off with the engine running.
Again guys, I really appreciate you having a look.
Marc
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <nuckolls.bob(at)aeroelectric.com> |
| Subject: | Re: Electrical diagram |
At 08:41 PM 4/30/2010, you wrote:
Bob and Joe, I want to thank you for reviewing my diagram. I appreciate it.
Have the start button on the e-bus was an oversight. I will move it
to the main bus. Thanks for catching that.
Leaving the baggage light on was taken into consideration and I'm
willing to take the risk on this one. I'm sure after if bites me a
couple of times, I'll reconsider.
One of the products under development is a variant
of the 9024 4-function module who's use is illustrated
in Figure Z9. It's a baggage/cabin light on-limit timer.
Further consider building your own baggage
light fixture using white, very bright LEDs readily available
from a lot of sources . . . I can send you some. 4-6 lamps
a 2-3 resistors would get you fixture that puts out
most adequate light with a power budget of 0.09 Amps.
We've pondered offering such a fixture with the timer
built in.
Joe, good call on putting the transponder and trim on e-bus. I will
probably do this as the transponder consumes little power.
The transponder is on the list of recommended clients for the
ebus as explained in Chapter 17 of the 'Connection.
The EFIS does annunciate a low voltage condition and crowbar over
voltage protection is built into the Plane Power alternator.
Bob, to be honest, I went with the single battery switch for
simplicity and cost. Much cheaper to purchase the two position
locking Honeywell toggle than the three position.
Why a locking $high$ switch? Hundreds of thousands
of GA aircraft including airplanes like the Beechjet
and Hawkers have perfectly ordinary toggle switches
to control ship's power sources.
Also, my thoughts were that I'm probably not going to be shutting
off the alternator that often. If I really need to then yes, I'm
going to be using the breaker as a switch. I called Plane Power
twice and made sure that this alternator will run fine without the
battery online, just in case the battery inadvertently got shut off
with the engine running.
See? You've properly identified a risk of human
error that became non-zero because of your
perception of another unqualified and certainly
unquantified risk. I.e. accidental mis-positioning
of the battery switch. This deliberation drove you to
purchase an expensive battery switch and created
a new operational risk.
The recipes for success in aviation electrical
systems are many and their operational histories
date back nearly a century. We would do well to
avail ourselves of that knowledge so that we
can build with confidence as opposed to jousting
with new worries and creating new risks.
Bob . . .
________________________________________________________________________________
| From: | "David LLoyd" <skywagon(at)charter.net> |
| Subject: | AeroElectric-List... PDF Problem...?? |
Hi Bob,
I was reviewing your files on.....
http://www.aeroelectric.com/Pictures/Curves/
Your lists are very much appreciated.
On this 'list' are two files for the Battery_Minder_Recharge.pdf.
Both of those files will not open in my cpu. All others on the list do open
normally. Before I get into my cpu, I thought possibly you could look at
the files and see if they got corrupted by a gremlin of sorts.....
David
_________________________________________________________
>
> Not all charger/maintainers are equal. Even amongst
> the Schumacher products, there are considerable variations
> depending on model. See:
>
> http://www.aeroelectric.com/Pictures/Curves/
>
> Behaviors for several Schumacher products are plotted
> there. We don't know why they all differ but we DO know
> that putting any RG battery on a constant "recharge"
> voltage or "trickle" charge current will kill it over
> time.
>
> If you see anything that looks like a "top off" behavior
> followed by an extended period of "relaxation" where
> the voltage drops below 14 volts, there is a strong
> likelihood that the device is doing good things for
> your RG battery.
>
> Bob . . .
>
>
> =========
> At 06:11 AM 3/18/2010, Radioflyer wrote:
>
>
> After several postings here about how this is the best no-nonsense
> maintainer for Pb-acid chemistry I got myself one from Walmart. Model SEM
> 1562A. I put it on an Odyssey PC625 and checked the voltages. The unit was
> charging at 15.6V. After 3 hrs, the float charge kicked in, hovering
> around 14.6 volts. Later I believe I found a review on Amazon from
> somebody who measured about the same voltages.
>
> Don't know that I would call it "the best". I have no
> first-hand knowledge or criteria by which I could
>
>
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <nuckolls.bob(at)aeroelectric.com> |
| Subject: | Re: AeroElectric-List... PDF Problem...?? |
On this 'list'
http://www.aeroelectric.com/Pictures/Curves/
are two files for the Battery_Minder_Recharge.pdf.
Both of those files will not open in my cpu. All others on the list
do open normally. Before I get into my cpu, I thought possibly you
could look at the files and see if they got corrupted by a gremlin of
sorts.....
David
I am mystified my friend. Both the Battery Minder and Battery Tender files
are pretty old and have been linked numerous times. I've just opened
them from this computer with no problems. You might reload your
Adobe Reader and see if that 'fixes' anything. Let me know
what you discover. First try right-clicking to download the
files to your hard drive and THEN see if your computer will
open them. It might be a 'linkage' thing between your browser
and the PDF reader.
Bob . . .
________________________________________________________________________________
| From: | "David LLoyd" <skywagon(at)charter.net> |
| Subject: | Re: AeroElectric-List... PDF Problem...?? |
Bob,
You were correct that there is a linking problem. I was able to save it to
the HD and then, was able to open it with my Adobe Reader 9.2. However,
when 9.2 opened the file it popped this error message.....(see attachment).
I have never seen this message before. Funny that all other files on your
list open normally and these 2 do not. I wonder if I update 9.2 to 9.3 if
that would solve the linking problem.
Your suggestions.....
David
___________________________________________________
----- Original Message -----
From: "Robert L. Nuckolls, III" <nuckolls.bob(at)aeroelectric.com>
Sent: Saturday, May 01, 2010 11:36 AM
Subject: Re: AeroElectric-List: AeroElectric-List... PDF Problem...??
>
>
>
> On this 'list'
>
> http://www.aeroelectric.com/Pictures/Curves/
>
> are two files for the Battery_Minder_Recharge.pdf.
>
> Both of those files will not open in my cpu. All others on the list do
> open normally. Before I get into my cpu, I thought possibly you could
> look at the files and see if they got corrupted by a gremlin of sorts.....
>
> David
>
> I am mystified my friend. Both the Battery Minder and Battery Tender
> files
> are pretty old and have been linked numerous times. I've just opened
> them from this computer with no problems. You might reload your
> Adobe Reader and see if that 'fixes' anything. Let me know
> what you discover. First try right-clicking to download the
> files to your hard drive and THEN see if your computer will
> open them. It might be a 'linkage' thing between your browser
> and the PDF reader.
>
> Bob . . .
>
>
>
________________________________________________________________________________
| From: | <robert.mccallum2(at)sympatico.ca> |
| Subject: | Re: AeroElectric-List... PDF Problem...?? |
Both files (and others on the site) opened fine for me using both Adobe re
ader (9.3.2) and also Foxit reader.(3.1.4.1125)
Bob McC
________________________________________________________________________________
| From: | Charlie England <ceengland(at)bellsouth.net> |
| Subject: | Re: AeroElectric-List... PDF Problem...?? |
Hi David,
I see one called battery minder and another called battery tender; both
open on my old xp machine with whatever version of pdf reader is used by
the Google Chrome browser.
Charlie
On 5/1/2010 1:21 PM, David LLoyd wrote:
>
>
> Hi Bob,
>
> I was reviewing your files on.....
>
> http://www.aeroelectric.com/Pictures/Curves/
>
> Your lists are very much appreciated.
> On this 'list' are two files for the Battery_Minder_Recharge.pdf.
> Both of those files will not open in my cpu. All others on the list
> do open normally. Before I get into my cpu, I thought possibly you
> could look at the files and see if they got corrupted by a gremlin of
> sorts.....
> David
>
> _________________________________________________________
>>
>> Not all charger/maintainers are equal. Even amongst
>> the Schumacher products, there are considerable variations
>> depending on model. See:
>>
>> http://www.aeroelectric.com/Pictures/Curves/
>>
>> Behaviors for several Schumacher products are plotted
>> there. We don't know why they all differ but we DO know
>> that putting any RG battery on a constant "recharge"
>> voltage or "trickle" charge current will kill it over
>> time.
>>
>> If you see anything that looks like a "top off" behavior
>> followed by an extended period of "relaxation" where
>> the voltage drops below 14 volts, there is a strong
>> likelihood that the device is doing good things for
>> your RG battery.
>>
>> Bob . . .
>>
>>
>> =========
>> At 06:11 AM 3/18/2010, Radioflyer wrote:
>>
>>
>> After several postings here about how this is the best no-nonsense
>> maintainer for Pb-acid chemistry I got myself one from Walmart. Model
>> SEM 1562A. I put it on an Odyssey PC625 and checked the voltages. The
>> unit was charging at 15.6V. After 3 hrs, the float charge kicked in,
>> hovering around 14.6 volts. Later I believe I found a review on
>> Amazon from somebody who measured about the same voltages.
>>
>> Don't know that I would call it "the best". I have no
>> first-hand knowledge or criteria by which I could
>>
________________________________________________________________________________
| From: | "David LLoyd" <skywagon(at)charter.net> |
| Subject: | Re: AeroElectric-List... PDF Problem...?? |
Bob,
Problem of opening old .pdf file fixed.
However, I am not sure of a specific fix.
I uninstalled my latest (AR) Adobe Reader 9.2, followed by a reboot and
installed AR 9.3. After it came up and went through its 'acceptance', etc.,
then all the .pdf files on you "curves" file link would open as normal.
It's good to have a repair work but, it would have been better to know the
specific reason my AR 9.2 did not work.
David
PS: for some you going through similar updating for PDF files, you should
know that the newest version does not function until you try and open a .pdf
file. Then, it comes up with the legal jargon that one must sign on to
before new version of AR go into operation.
________________________________________________________
----- Original Message -----
From: "Robert L. Nuckolls, III" <nuckolls.bob(at)aeroelectric.com>
Sent: Saturday, May 01, 2010 11:36 AM
Subject: Re: AeroElectric-List: AeroElectric-List... PDF Problem...??
>
>
>
> On this 'list'
>
> http://www.aeroelectric.com/Pictures/Curves/
>
> are two files for the Battery_Minder_Recharge.pdf.
>
> Both of those files will not open in my cpu. All others on the list do
> open normally. Before I get into my cpu, I thought possibly you could
> look at the files and see if they got corrupted by a gremlin of sorts.....
>
> David
>
> I am mystified my friend. Both the Battery Minder and Battery Tender
> files
> are pretty old and have been linked numerous times. I've just opened
> them from this computer with no problems. You might reload your
> Adobe Reader and see if that 'fixes' anything. Let me know
> what you discover. First try right-clicking to download the
> files to your hard drive and THEN see if your computer will
> open them. It might be a 'linkage' thing between your browser
> and the PDF reader.
>
> Bob . . .
>
>
>
________________________________________________________________________________
| Subject: | Bulkhead connector |
| From: | Richard Girard <aslsa.rng(at)gmail.com> |
Folks, Sorry to weigh in on this so late, but I found the nifty PL 259
chassis connector (on the right in the photo) at Radio Shack during a parts
run on Friday. Part number is 278-0201. I already had a BNC cable so I
bought an adapter (PN 278-121), too.
Rick Girard
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <nuckolls.bob(at)aeroelectric.com> |
| Subject: | Re: Bulkhead connector |
At 07:39 AM 5/2/2010, you wrote:
>Folks, Sorry to weigh in on this so late, but I found the nifty PL
>259 chassis connector (on the right in the photo) at Radio Shack
>during a parts run on Friday. Part number is 278-0201. I already had
>a BNC cable so I bought an adapter (PN 278-121), too.
I guess I'm disconnected from the thread. How are
you using these parts?
Bob . . .
________________________________________________________________________________
| Subject: | Re: Bulkhead connector |
| From: | Richard Girard <aslsa.rng(at)gmail.com> |
Bob, I'm going to solder a piece of 3/32" brazing rod into the center lug of
the PL 259 chassis mount (the lug is drilled out to let it slip in for a
good mechanical attachment once the soldering is done), trim to appropriate
length and use it as an antenna for my hand held.
Rick
On Sun, May 2, 2010 at 9:23 AM, Robert L. Nuckolls, III <
nuckolls.bob(at)aeroelectric.com> wrote:
> nuckolls.bob(at)aeroelectric.com>
>
>
> At 07:39 AM 5/2/2010, you wrote:
>
>> Folks, Sorry to weigh in on this so late, but I found the nifty PL 259
>> chassis connector (on the right in the photo) at Radio Shack during a parts
>> run on Friday. Part number is 278-0201. I already had a BNC cable so I
>> bought an adapter (PN 278-121), too.
>>
>
> I guess I'm disconnected from the thread. How are
> you using these parts?
>
> Bob . . .
>
>
________________________________________________________________________________
| Subject: | Re: Bulkhead connector |
| From: | "edleg" <ed_legault(at)yahoo.com> |
Once you get the piece of brazing rod soldered in, and it cools down, you might
want to pack that area around the base of the antenna full of RTV to help make
it watertight.
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=296528#296528
________________________________________________________________________________
| Subject: | Re: IVO Prop Current Limiter/Electronic Circuit Breaker |
| From: | "user9253" <fran4sew(at)banyanol.com> |
> Dennis
> Do you have a circuit diagram/photos of your installation that you can
> share??
> Thanks
> Dick
Dick,
Did you see this picture that Dennis posted?
http://forums.matronics.com/viewtopic.php?t=70557&sid=1bdd10db5d3c9ab625b4465b86c3de08
No modification is required to the existing prop motor circuit. Just find some
slack in a wire going to the motor (hot or ground doesn't matter) and wrap 3
turns around a reed switch. Then connect the reed switch in series with a power
source and indicator LED. The reed switch is made of glass and will break
easily. It should not be stressed by the lead wires or while wrapping with turns
of wire. Also, a heat-sink should be used if soldered because the switch
will be damaged by heat.
Joe
--------
Joe Gores
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=296570#296570
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <nuckolls.bob(at)aeroelectric.com> |
| Subject: | Re: Bulkhead connector |
At 01:37 PM 5/2/2010, you wrote:
>Bob, I'm going to solder a piece of 3/32" brazing rod into the
>center lug of the PL 259 chassis mount (the lug is drilled out to
>let it slip in for a good mechanical attachment once the soldering
>is done), trim to appropriate length and use it as an antenna for my hand held.
Okay, figure out a way to substantially beef up support
of the rod right and for about 1" away from the solder
joint. If allowed to "wave in be breeze" it's going
break at the solder joint and depart the airplane . . .
if I recall your airplane configuration correctly,
there may be risk of putting that piece of wire through the prop?
A piece of Delrin, polycarbonate, etc cut drilled and
mounted to supply support is recommended.
Bob . . .
________________________________________________________________________________
| From: | RGent1224(at)aol.com |
| Subject: | Re: IVO Prop Current Limiter/Electronic Circuit |
Breaker
Joe
Dennis sent me some additional photos and a wiring diagram off line showing
what I wanted to know.
I will be modifying the wiring some when I get to that project
Thanks
Dick
In a message dated 5/3/2010 7:26:59 A.M. Central Daylight Time,
fran4sew(at)banyanol.com writes:
--> AeroElectric-List message posted by: "user9253"
> Dennis
> Do you have a circuit diagram/photos of your installation that you can
> share??
> Thanks
> Dick
Dick,
Did you see this picture that Dennis posted?
http://forums.matronics.com/viewtopic.php?t=70557&sid=1bdd10db5d3c9ab625b446
5b86c3de08
No modification is required to the existing prop motor circuit. Just find
some slack in a wire going to the motor (hot or ground doesn't matter) and
wrap 3 turns around a reed switch. Then connect the reed switch in
series with a power source and indicator LED. The reed switch is made of glass
and will break easily. It should not be stressed by the lead wires or
while wrapping with turns of wire. Also, a heat-sink should be used if
soldered because the switch will be damaged by heat.
Joe
--------
Joe Gores
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=296570#296570
________________________________________________________________________________
| From: | "Mauri Morin" <maurv8(at)gmail.com> |
Bob,
I'm in the process of wiring my RV-8 and have a switch on the Infinity
grip to control the Airflow Performance (API) aux fuel pump.
The literature on the pump says the current draw is 5 amps at 12 volts
and should be protected with a 10 amp c/b.
The switch in the grip is rated at 6 amp at 12volts.
API engineering thinks the switch in the grip may not be able to handle
the inrush current on the pump when actitivated and thinks I should use
a relay which I'd rather not do.
J.D at Infinity Aerospace thinks a zener diode will solve this problem
and suggested I check with you for your opinion and a possible circuit.
Since this combination of grip and pump has been used in a lot of RVs, I
thought that, if this was a problem, it would have been solved by
someone already.
Mauri Morin
Ronan, MT
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <nuckolls.bob(at)aeroelectric.com> |
| Subject: | Re: Infinity grip |
At 06:30 PM 5/4/2010, you wrote:
>Bob,
>I'm in the process of wiring my RV-8 and have a switch on the
>Infinity grip to control the Airflow Performance (API) aux fuel pump.
>The literature on the pump says the current draw is 5 amps at 12
>volts and should be protected with a 10 amp c/b.
>The switch in the grip is rated at 6 amp at 12volts.
>API engineering thinks the switch in the grip may not be able to
>handle the inrush current on the pump when actitivated and thinks I
>should use a relay which I'd rather not do.
>J.D at Infinity Aerospace thinks a zener diode will solve this
>problem and suggested I check with you for your opinion and a possible circuit.
>
>Since this combination of grip and pump has been used in a lot of
>RVs, I thought that, if this was a problem, it would have been
>solved by someone already.
API is correct in that some sort of buffering
between the switch and motor is called for.
It's probably a PM motor with a significant
spin-up transient. The relay is the simplest.
You can do it with a single transistor and a
few jelly bean components too. I can sketch
either.
Bob . . .
________________________________________________________________________________
| From: | "CHARLES T BECKER" <ctbecker(at)atlanticbb.net> |
| Subject: | Re: Infinity grip |
For peace of mind and reduced complexity, I'd use the
relays. It keeps all the really high currents out of the
grip.
Charlie
"Mauri Morin" wrote:
> Bob,
> I'm in the process of wiring my RV-8 and have a switch
>on the Infinity grip to control the Airflow Performance
>(API) aux fuel pump.
> The literature on the pump says the current draw is 5
>amps at 12 volts and should be protected with a 10 amp
>c/b.
> The switch in the grip is rated at 6 amp at 12volts.
> API engineering thinks the switch in the grip may not be
>able to handle the inrush current on the pump when
>actitivated and thinks I should use a relay which I'd
>rather not do.
> J.D at Infinity Aerospace thinks a zener diode will
>solve this problem and suggested I check with you for
>your opinion and a possible circuit.
>
> Since this combination of grip and pump has been used in
>a lot of RVs, I thought that, if this was a problem, it
>would have been solved by someone already.
>
> Mauri Morin
> Ronan, MT
>
________________________________________________________________________________
| From: | "rparigoris" <rparigor(at)suffolk.lib.ny.us> |
Hi Group
I have a few questions about D-sub connectors:
**How many amps are each pin good for using the nice machined pins?
**How many amps are each pin good for using solder on pins?
**I want to run my Ray Allen pitch and roll servo wiring through D-sub connector.
Would it be advisable, especially on the pitch to parallel two pins?
**I need to run 4 shielded wires out on my instrument module (2ea. mic and speaker).
I would like to use a D-sub connector on the bottom port side of my instrument
module to allow easier instrument module removal and install. Thus there
will be a few inches of unshielded wires at the connector:
$$Should I use D-sub shielded shells? This D-sub connector is about 5" away from
my Dynon D-10A
**I have a single point ground on firewall with field of tabs. I think I remember
seeing for avionics and instruments (can't find it) a D-sub connector with
perhaps 3 or 4 wires going to field of tabs, and all the pins connected to one
side to those 3 or 4 wires to make a field of pins to be used for single point
ground. Is this acceptable for grounding on the same connector:
$$mic and speaker shield?
$$Radio and transponder grounds?
$$Instrument grounds?
Thx.
Ron Parigoris
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=296854#296854
________________________________________________________________________________
| Subject: | Re: Infinity grip |
| From: | "Eric M. Jones" <emjones(at)charter.net> |
A word on switches:
The make switches in runs of tens-of-millions, where minor costs are serious concerns--and
that's why they squeeze every penny out of the design. (And that's
why your Exacto knife doesn't have a one-cent washer between the handle and the
collar).
So it's easy to find out that your switches are too cheap for the job, especially
switches that don't have jungle-environment ratings, which they really need
when you are 20 miles from the airport and you hear that funny sound....
My philosophy is to use environmentally sealed switches on control sticks. People
sweat an awful lot. Oddly enough, computer joysticks frequently have excellent
(but low current) switches.
My Glastar (the plan is...) should have two Saitek Cyborg 2000 stick grips which
have half a dozen cool features (and adjustments with metal fasteners) not found
elsewhere.
--------
Eric M. Jones
www.PerihelionDesign.com
113 Brentwood Drive
Southbridge, MA 01550
(508) 764-2072
emjones(at)charter.net
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=296856#296856
________________________________________________________________________________
| Subject: | Re: Infinity grip |
| From: | "rampil" <ira.rampil(at)gmail.com> |
Just out of curiousity, why do you feel the need for an Aux pump control
on your stick? It seems that you would only use it at the start and end
(perhaps) of a flight, and stick controls should generally be reserved for
things that you fiddle with frequently during a flight.
This would seem especially true after learning that the switch is not
adequate for the pump you bought.
--------
Ira N224XS
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=296862#296862
________________________________________________________________________________
| Subject: | firewall shields... yet again |
| From: | "jayb" <jaybrinkmeyer(at)yahoo.com> |
I've been reading a lot about firewall shields lately.
For split shields like 61-300 from Aircraft Spruce... If using over existing wires,
is it designed to cover the existing grommet? Or maybe it's assumed that
there isn't an existing grommet? I can't see how any new grommet would be applied
for existing wires unless that grommet were split too. Maybe I'm just missing
something obvious.
These look pretty interesting for new wire runs... http://precision-grommets.com. Lots of sizes and available in stainless too.
Regards,
Jay
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=296864#296864
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <nuckolls.bob(at)aeroelectric.com> |
| Subject: | Re: firewall shields... yet again |
At 02:09 PM 5/5/2010, you wrote:
I've been reading a lot about firewall shields lately.
For split shields like 61-300 from Aircraft Spruce... If using over
existing wires, is it designed to cover the existing grommet?
The shields are to protect a grommet which is part of
the complete installation.
Or maybe it's assumed that there isn't an existing grommet?
There must be one. Also, it's also a good idea to
use some fire-putty to put a nice fillet around the
wires and cover the gap between the shield an
grommet underneath.
I can't see how any new grommet would be applied for existing wires
unless that grommet were split too.
Yup, that's what you have to do. It's commonly done
to replace aged and degraded grommets with new ones
without pulling the wires out of the hole.
Maybe I'm just missing something obvious.
These look pretty interesting for new wire
runs... http://precision-grommets.com.
Lots of sizes and available in stainless too.
Emacs!
Certainly a class act product. Keep in mind that
the PRIMARY purpose of a grommet is to mechanically
separate and isolate relatively vulnerable wire
insulation from the sharp edge of a fire-wall
sheet or other thin penetration. Maintaining
fire-wall integrity calls for gas-tightness with
some degree of resistance to fuel fed flames.
Of course, the classic rubber/plastic grommet has
no resistance to flames so we have to add the
steel shields and fire-putty to add flame resistance
to the assembly.
Grommets like those shown above are obviously
flame resistant but we're still interested in
the best-we-know-how-to-do for gas tightness
too. So perhaps the fire-putty fillet on the
engine side is still called for.
Bob . . .
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <nuckolls.bob(at)aeroelectric.com> |
| Subject: | Re: D-sub questions |
At 12:46 PM 5/5/2010, you wrote:
>
>
>Hi Group
>
>I have a few questions about D-sub connectors:
>
>**How many amps are each pin good for using the nice machined pins?
The continuous rating for individual pins is 7A
>**How many amps are each pin good for using solder on pins?
Same . . .
You can run a LOT of current through a D-sub connector. See:
http://www.aeroelectric.com/Pictures/Connectors/D-Subminature/Paralleled_D-Sub_Pins.jpg
I used this technique to run 20+ amps through D-subs on
this vehicle's . . .
http://aeroelectric.com/Pictures/Misc/GQM_1st_Ops_Flight.jpg
DC power distribution assembly . . .
http://aeroelectric.com/Pictures/Misc/GQM_Power_Dist.jpg
which featured solid state switching. In this application,
we de-rated pins to 4A each and paralleled 5 pins for
the 20A conductors. The de-rating was in recognition of
our 70C max operating environment.
>**I want to run my Ray Allen pitch and roll servo wiring through
>D-sub connector. Would it be advisable, especially on the pitch to
>parallel two pins?
Can't think of a good reason why.
>**I need to run 4 shielded wires out on my instrument module (2ea.
>mic and speaker). I would like to use a D-sub connector on the
>bottom port side of my instrument module to allow easier instrument
>module removal and install. Thus there will be a few inches of
>unshielded wires at the connector:
>$$Should I use D-sub shielded shells? This D-sub connector is about
>5" away from my Dynon D-10A
No, take shields through the connectors on their
own pins. Actually, these signals can be carried
very nicely on twisted pairs and/or trios with
no shielding but if you choose to shield, treat
the shields as separate conductors.
>**I have a single point ground on firewall with field of tabs. I
>think I remember seeing for avionics and instruments (can't find it)
>a D-sub connector with perhaps 3 or 4 wires going to field of tabs,
>and all the pins connected to one side to those 3 or 4 wires to make
>a field of pins to be used for single point ground. Is this
>acceptable for grounding on the same connector:
>$$mic and speaker shield?
>$$Radio and transponder grounds?
>$$Instrument grounds?
FOLLOW THE WIRING DIAGRAM FOR THE PRODUCTS YOU
ARE INSTALLING.
Shields on wires that run between black boxes
GENERALLY terminate on either some specific pin
in a connector or the connector's back-shell.
They NEVER get long pigtails off to some remote
ground location.
The grounding configurations shown in Appendix Z
are for accessory power grounds, not system signal
or shield grounds.
Bob . . .
________________________________________________________________________________
| Subject: | Latest on Alternators, Regulators, Archives, Etc. |
| From: | Jared Yates <email(at)jaredyates.com> |
I've been researching the archives with regard to incorporating ND
alternators, and there is a lot of message traffic from the mid 2000s about
the yet to be accomplished load dump research. I didn't really see a
conclusion to that research. Did I miss it, or is it still underway?
It seems that some things have changed over the past few years. It looks
like Niagara isn't selling a kit with the ND alternator anymore? Vans is
only selling a plane power alternator in their store? Should I take any
information from those changes (if they really are changes)?
So what is the latest? Is there anything approaching a consensus that
would lead me towards a plane power package vs a ND system? (especially, has
such a consensus emerged in the past 2 or 3 years, since there obviously
wasn't one back then).
I get the idea from the connection that Bob doesn't find the internal
automotive regulators to be adequate for aviation use. Has anyone heard him
comment specifically about the aviation adequacy of the internal regulator
that plane power uses, supposedly with crowbar overvoltage protection
included?
If this is old news and it has already been covered, feel free to tell me
and I'll try to find it.
The question that I'm researching to answer is "which alternator should I
use?" I like the idea of local replacements for the ND setups, and I
wouldn't mind learning how to use an external regulator and crowbar OV
system on an automotive alternator. I'm also not afraid of a little
fabrication, but I also like the sound of the plane power sales pitch when
it comes to fan rotation direction and long life brushes, with all of the
right brackets and such being a nice bonus. I should say that I'm shopping
for a primary alternator in the 40-60A range to incorporate into Z-13/8 on a
Lycoming 360.
Thanks for your help,
Jared
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <nuckolls.bob(at)aeroelectric.com> |
| Subject: | Re: Latest on Alternators, Regulators, Archives, |
Etc.
At 03:42 PM 5/6/2010, you wrote:
I've been researching the archives with regard to incorporating ND
alternators, and there is a lot of message traffic from the mid 2000s
about the yet to be accomplished load dump research. I didn't really
see a conclusion to that research. Did I miss it, or is it still underway?
No, it was something of a red-herring. Any automotive
alternator worth the price of it's brand name will withstand
it's own load-dump transient. See the rev 12 chapter on
alternators in the 'Connection.
http://aeroelectric.com/R12A/03_Alternator_12A1.pdf
I visited a very large scale re-manufacturing operation a
few years ago and witnessed a full load, max rpm, max
temperature load-dump demonstration. The folks doing the
test said that they routinely subjected their products
to 5 such dumps in a row to verify their robustness.
It seems that some things have changed over the past few years. It
looks like Niagara isn't selling a kit with the ND alternator
anymore? Vans is only selling a plane power alternator in their
store? Should I take any information from those changes (if they
really are changes)?
So what is the latest? Is there anything approaching a consensus
that would lead me towards a plane power package vs a ND system?
(especially, has such a consensus emerged in the past 2 or 3 years,
since there obviously wasn't one back then).
The Plane Power IS an ND alternator modified for external
field supply so that an external, crow-bar ov protection
module can be added to the back of the device thus making
it conform to the legacy notions of how generators and
alternators should behave in airplanes.
I get the idea from the connection that Bob doesn't find the internal
automotive regulators to be adequate for aviation use. Has anyone
heard him comment specifically about the aviation adequacy of the
internal regulator that plane power uses, supposedly with crowbar
overvoltage protection included?
Your perception is incorrect. Again referring to chapter
3of the connection, see the passage starting with the
next to last paragraph in second column of page 3-2.
The problem I had with recommending UNMODIFIED automotive
is that the legacy control and ov protection design goals
could not be met. There was never anything wrong with the
capability of the built in regulator. Plane Power uses
the regulator that comes with the commercial off the shelf
alternator and MODIFIES the circuitry to agree with legacy
design goals.
If this is old news and it has already been covered, feel free to
tell me and I'll try to find it.
The question that I'm researching to answer is "which alternator
should I use?" I like the idea of local replacements for the ND
setups, and I wouldn't mind learning how to use an external regulator
and crowbar OV system on an automotive alternator. I'm also not
afraid of a little fabrication, but I also like the sound of the
plane power sales pitch when it comes to fan rotation direction and
long life brushes, with all of the right brackets and such being a
nice bonus. I should say that I'm shopping for a primary alternator
in the 40-60A range to incorporate into Z-13/8 on a Lycoming 360.
Buying a ready-to-bolt-on kit with all the brackets
has its advantages. The Plane Power offering is a
good value. Modifying your own automotive take-off
to run an external regulator, ov protection and
lv monitor is also an opportunity for good value and
better understanding of how it all goes together.
The "long life brushes" and "fan direction" have
not proven to be an issue in thousands of automotive
adaptations to aircraft.
Bob . . .
________________________________________________________________________________
| Subject: | Re: Latest on Alternators, Regulators, Archives, Etc. |
| From: | Jared Yates <email(at)jaredyates.com> |
Thanks! Those are great answers and they move my research along nicely.
On Thu, May 6, 2010 at 5:34 PM, Robert L. Nuckolls, III <
nuckolls.bob(at)aeroelectric.com> wrote:
> nuckolls.bob(at)aeroelectric.com>
>
> At 03:42 PM 5/6/2010, you wrote:
> I've been researching the archives with regard to incorporating ND
> alternators, and there is a lot of message traffic from the mid 2000s about
> the yet to be accomplished load dump research. I didn't really see a
> conclusion to that research. Did I miss it, or is it still underway?
>
> No, it was something of a red-herring. Any automotive
> alternator worth the price of it's brand name will withstand
> it's own load-dump transient. See the rev 12 chapter on
> alternators in the 'Connection.
>
> http://aeroelectric.com/R12A/03_Alternator_12A1.pdf
>
> I visited a very large scale re-manufacturing operation a
> few years ago and witnessed a full load, max rpm, max
> temperature load-dump demonstration. The folks doing the
> test said that they routinely subjected their products
> to 5 such dumps in a row to verify their robustness.
>
> It seems that some things have changed over the past few years. It looks
> like Niagara isn't selling a kit with the ND alternator anymore? Vans is
> only selling a plane power alternator in their store? Should I take any
> information from those changes (if they really are changes)?
>
> So what is the latest? Is there anything approaching a consensus that
> would lead me towards a plane power package vs a ND system? (especially, has
> such a consensus emerged in the past 2 or 3 years, since there obviously
> wasn't one back then).
>
> The Plane Power IS an ND alternator modified for external
> field supply so that an external, crow-bar ov protection
> module can be added to the back of the device thus making
> it conform to the legacy notions of how generators and
> alternators should behave in airplanes.
>
> I get the idea from the connection that Bob doesn't find the internal
> automotive regulators to be adequate for aviation use. Has anyone heard him
> comment specifically about the aviation adequacy of the internal regulator
> that plane power uses, supposedly with crowbar overvoltage protection
> included?
>
> Your perception is incorrect. Again referring to chapter
> 3of the connection, see the passage starting with the
> next to last paragraph in second column of page 3-2.
>
> The problem I had with recommending UNMODIFIED automotive
> is that the legacy control and ov protection design goals
> could not be met. There was never anything wrong with the
> capability of the built in regulator. Plane Power uses
> the regulator that comes with the commercial off the shelf
> alternator and MODIFIES the circuitry to agree with legacy
> design goals.
>
> If this is old news and it has already been covered, feel free to tell me
> and I'll try to find it.
>
> The question that I'm researching to answer is "which alternator should I
> use?" I like the idea of local replacements for the ND setups, and I
> wouldn't mind learning how to use an external regulator and crowbar OV
> system on an automotive alternator. I'm also not afraid of a little
> fabrication, but I also like the sound of the plane power sales pitch when
> it comes to fan rotation direction and long life brushes, with all of the
> right brackets and such being a nice bonus. I should say that I'm shopping
> for a primary alternator in the 40-60A range to incorporate into Z-13/8 on a
> Lycoming 360.
>
> Buying a ready-to-bolt-on kit with all the brackets
> has its advantages. The Plane Power offering is a
> good value. Modifying your own automotive take-off
> to run an external regulator, ov protection and
> lv monitor is also an opportunity for good value and
> better understanding of how it all goes together.
>
> The "long life brushes" and "fan direction" have
> not proven to be an issue in thousands of automotive
> adaptations to aircraft.
>
> Bob . . .
>
>
________________________________________________________________________________
| From: | Mark Davis <marksdavis(at)cox.net> |
Bob,
The list discussion yesterday re: powering the fuel pump thru a switch
on the Infinity stick grip in a RV indicated that this should be done
either with the use of a relay or a Zener diode. I'm helping a friend
wire his RV-7A and he wants to do this as well but only with one of the
push buttons switches on the stick in parallel with the on-off rocker
switch on the panel. The pushbutton is only to be used to help during
starting the engine. Since space and already installed wiring make use
of relay pretty much a non-starter, use of a Zener diode looks like the
best solution. Unfortunately, I lack the knowledge and experience to
determine the correct Zener size and just how it should be wired into
the circuit to deal with the inrush current problem for the stick
switch. I'd very much appreciate any help/direction you could provide
in this regard.
Thanks,
Mark Davis
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <nuckolls.bob(at)aeroelectric.com> |
I have an extra hand-held GPS 310 that is the second such
radio I ever owned. In spite of dearth of gee-whiz features
it took me right over the center of many an airport.
It would make a good flight-bag back up for your
"plan-B". It is back-lit and runs on 2xAA alkaline
cells.
Would like to get $25 + postage for it.
Emacs!
Bob . . .
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <nuckolls.bob(at)aeroelectric.com> |
| Subject: | Re: Zener Diode Use |
At 09:49 AM 5/7/2010, you wrote:
>
>Bob,
>
>The list discussion yesterday re: powering the fuel pump thru a
>switch on the Infinity stick grip in a RV indicated that this should
>be done either with the use of a relay or a Zener diode.
NO zener, relay only.
> I'm helping a friend wire his RV-7A and he wants to do this as
> well but only with one of the push buttons switches on the stick in
> parallel with the on-off rocker switch on the panel. The
> pushbutton is only to be used to help during starting the
> engine. Since space and already installed wiring make use of relay
> pretty much a non-starter, use of a Zener diode looks like the best solution.
Except that it is a non-solution . . .
> Unfortunately, I lack the knowledge and experience to determine
> the correct Zener size and just how it should be wired into the
> circuit to deal with the inrush current problem for the stick
> switch. I'd very much appreciate any help/direction you could
> provide in this regard.
This really isn't a very good idea. Switches on the stick
grip get more abuse than switches on the panel, yet they
are the least robust. They add failure modes that are at
least a nuisance but when wired to ship's systems, they
add RISK.
Please don't do this.
Bob . . .
________________________________________________________________________________
| Subject: | Re: Flightbag GPS |
| From: | Richard Girard <aslsa.rng(at)gmail.com> |
Bob, I'll take it if it's not already spoken for.
Rick Girard
Udall
On Fri, May 7, 2010 at 11:33 AM, Robert L. Nuckolls, III <
nuckolls.bob(at)aeroelectric.com> wrote:
> I have an extra hand-held GPS 310 that is the second such
> radio I ever owned. In spite of dearth of gee-whiz features
> it took me right over the center of many an airport.
> It would make a good flight-bag back up for your
> "plan-B". It is back-lit and runs on 2xAA alkaline
> cells.
>
> Would like to get $25 + postage for it.
>
> [image: Emacs!]
>
>
> Bob . . .
>
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <nuckolls.bob(at)aeroelectric.com> |
| Subject: | Re: Flightbag GPS |
At 12:42 PM 5/7/2010, you wrote:
>Bob, I'll take it if it's not already spoken for.
>
>Rick Girard
>Udall
You are the first to respond. Give me a call
at 316-209-7528 and we'll arrange for the
exchange.
Bob . . .
________________________________________________________________________________
| From: | RGent1224(at)aol.com |
| Subject: | Re: Flightbag GPS |
You can get a cigarette plug power adapter for them on Ebay
In a message dated 5/7/2010 1:05:40 P.M. Central Daylight Time,
nuckolls.bob(at)aeroelectric.com writes:
--> AeroElectric-List message posted by: "Robert L. Nuckolls, III"
At 12:42 PM 5/7/2010, you wrote:
>Bob, I'll take it if it's not already spoken for.
>
>Rick Girard
>Udall
You are the first to respond. Give me a call
at 316-209-7528 and we'll arrange for the
exchange.
Bob . . .
________________________________________________________________________________
| From: | <bakerocb(at)cox.net> |
| Subject: | Interesting Products |
5/8/2010
Some products that may be of interest to list members:
http://www.qcavionix.com/index.php?cat=10000
'OC' Says: "The best investment we can make is the effort to gather and
understand knowledge."
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <nuckolls.bob(at)aeroelectric.com> |
| Subject: | IVO Prop Motor Current Limiter and Electronic CB |
Somebody was willing to build the circuit I proposed and
was asking about sources for the power mos-fet called out
on the drawing. I left that note on my computer in Wichita
so I'm sort of broadcasting this response in the blind . . .
I used Digikey as the first-source for any drawings I
publish. They stock an extensive collection of International
Rectifier parts. You'll be able to find the IR mos-fet
here . . .
http://www.digikey.com
Bob . . .
________________________________________________________________________________
| From: | Mike Welch <mdnanwelch7(at)hotmail.com> |
| Subject: | IVO Prop Motor Current Limiter and Electronic |
CB
Hi Bob=2C
That was me that asked about the mos-fet. I had made out my shopping lis
t of parts on Mouser=2C and when it was almost finished=2C I got to the IRF
P 3703. No matter how hard I tried=2C I just couldn't come up with one tha
t they carry.
Since it took me quite awhile to fill out the Mouser shopping cart=2C I w
as wondering if you knew of a compatible version of the 3703 that Mouser se
lls.
Mike Welch
PS. I did find it on Digikey=2C but I was hoping to get everything from on
e vendor. Thnx
> Somebody was willing to build the circuit I proposed and
> was asking about sources for the power mos-fet called out
> on the drawing.
> I used Digikey as the first-source for any drawings I
> publish. They stock an extensive collection of International
> Rectifier parts. You'll be able to find the IR mos-fet
> here . . .
>
> http://www.digikey.com
>
>
>
> Bob . . .
>
>
===========
===========
===========
===========
>
>
>
_________________________________________________________________
Hotmail has tools for the New Busy. Search=2C chat and e-mail from your inb
ox.
http://www.windowslive.com/campaign/thenewbusy?ocid=PID28326::T:WLMTAGL:O
N:WL:en-US:WM_HMP:042010_1
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <nuckolls.bob(at)aeroelectric.com> |
| Subject: | IVO Prop Motor Current Limiter and Electronic |
CB
At 07:07 PM 5/8/2010, you wrote:
>Hi Bob,
>
> That was me that asked about the mos-fet. I had made out my
> shopping list of parts on Mouser, and when it was almost finished,
> I got to the IRFP 3703. No matter how hard I tried, I just
> couldn't come up with one that they carry.
> Since it took me quite awhile to fill out the Mouser shopping
> cart, I was wondering if you knew of a compatible version of the
> 3703 that Mouser sells.
>
>Mike Welch
>PS. I did find it on Digikey, but I was hoping to get everything
>from one vendor. Thn
The 3703 was selected for its very low on-resistance
where IR is sort of the defacto champion in that
arena.
I'm not familiar with the Mouser product offerings.
Bob . . .
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <nuckolls.bob(at)aeroelectric.com> |
| Subject: | IVO Prop Motor Current Limiter and Electronic |
CB
At 07:07 PM 5/8/2010, you wrote:
>Hi Bob,
>
> That was me that asked about the mos-fet. I had made out my
> shopping list of parts on Mouser, and when it was almost finished,
> I got to the IRFP 3703. No matter how hard I tried, I just
> couldn't come up with one that they carry.
> Since it took me quite awhile to fill out the Mouser shopping
> cart, I was wondering if you knew of a compatible version of the
> 3703 that Mouser sells.
Try the FDU6688_Q
Bob . . .
________________________________________________________________________________
| From: | "Dennis & Anne Glaeser" <glaesers(at)wideopenwest.com> |
| Subject: | RE: IVO Prop Motor Current Limiter and Electronic CB |
I made the original circuit that Bob posted. I got all the parts from
DigiKey, including the IRFP 3703.
I was finally able to test that circuit today. It worked exactly as
predicted. With only the 0.1 ohm resistor, the current was limited to about
6 amps. This did not allow the motor to go as far as desired. So I added the
parallel 0.5 ohm resistors one at a time. With both in place, it allows a
bit over 8 amps, which is where the motor just starts to strain. This is
also about the same place where the reed switch triggers.
The mosfet does get rather warm, but only if the switch is held longer than
normal.
I also plan to build the Electronic CB circuit. When it was published, Bob's
said to wait until others had a chance to review and comment before
building, so I haven't begun that process yet.
Dennis Glaeser
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <nuckolls.bob(at)aeroelectric.com> |
| Subject: | Wire identification |
Comments/Questions: On the Power Distribution diagrams it doesn't
show any special color for various wires.
Just wondered, there are so many wires in even a small like my RV-4,
should there be different colors for certain connections.
I know RED is for power and BLACK is for ground but are other colors
generally used for other connections or are all wires just considered
either power or ground?
The notion of marking wires with either colors or
legends goes to the future task of troubleshooting.
When you're installing wires, you pretty much know
where they go and what they do. Further, there
are so few wires total in a small aircraft that
spending the $time$ to add any special identification
to a wire adds little value in the future.
Finally, wire is not cheap but buying in full
spools or lots of 100' can save you some money.
You don't want to have long spools of many
colors that leaves you with a lot of left over
wire at the end of your project.
Suggest you go with what ever color (usually
white) that makes sense economically. If you
want to label some or all of them, consider
paper labels held on the ends of the wire runs
with clear heatshrink like . . .
http://aeroelectric.com/Pictures/Wiring_Technique/Wire_Marking.jpg
Bob . . .
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <nuckolls.bob(at)aeroelectric.com> |
| Subject: | Re: RE: IVO Prop Motor Current Limiter and Electronic |
CB
At 10:20 PM 5/8/2010, you wrote:
I made the original circuit that Bob posted. I got all the parts from
DigiKey, including the IRFP 3703.
I was finally able to test that circuit today. It worked exactly as
predicted. With only the 0.1 ohm resistor, the current was limited to about
6 amps. This did not allow the motor to go as far as desired. So I added the
parallel 0.5 ohm resistors one at a time. With both in place, it allows a
bit over 8 amps, which is where the motor just starts to strain. This is
also about the same place where the reed switch triggers.
The mosfet does get rather warm, but only if the switch is held longer than
normal.
I've had a lot of folks become concerned with transistors
that got "rather warm" but without puting some form of
instrumentation on the device and then accounting for
thermal resistances in the heat-energy transfer path,
"rather warm" is a rather loose quantification term.
There are instances where the surface temperature of
a power device can get up to "sizzle-spit" temperatures
and still be within operating limits. So if your finger-test
of the device did not send you looking for the burn
ointment, then there's a high probability that the
transistor as installed and operated is going to be
okay . . .
I also plan to build the Electronic CB circuit. When it was published, Bob's
said to wait until others had a chance to review and comment before
building, so I haven't begun that process yet.
Go ahead an 'brass-board' it if you can. I'm still to tied
up with table saws and paint brushes to spend time at
the bench.
Do you have access to a 'scope? It would be interesting
to fine-tune/verify the value of the capacitor to make the
circuit trip in 200-500 milliseconds after the
green light comes on.
Thanks for your help in the development effort.
Bob . . .
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <nuckolls.bob(at)aeroelectric.com> |
| Subject: | Re: RE: IVO Prop Motor Current Limiter and Electronic |
CB
>I was finally able to test that circuit today. It worked exactly as
>predicted. With only the 0.1 ohm resistor, the current was limited to about
>6 amps. This did not allow the motor to go as far as desired. So I added the
>parallel 0.5 ohm resistors one at a time. With both in place, it allows a
>bit over 8 amps, which is where the motor just starts to strain. This is
>also about the same place where the reed switch triggers.
Hmmmm . . . for the final configuration you'll probably want
to increase the current limit on up to 10A. Without knowing
the modulus of elasticity of the prop materials with respect
to temperature, you don't want to loose pitch-stroke because
the current limit it set too low. So paralleling the .1 ohm
with .2 ohms will produce a total of 1/(1/0.2 + 1/0.1)= 0.066
ohms which should boost the limit to just over 10A.
Adding the 200-500 millisecond trip over ride should allow
you to flirt at the edges of the 10 C/B value without
tripping it.
Bob . . .
________________________________________________________________________________
| From: | "Dennis & Anne Glaeser" <glaesers(at)wideopenwest.com> |
| Subject: | RE: IVO Prop Motor Current Limiter and Electronic CB |
The mosfet does get rather warm, but only if the switch is held longer than
normal.
I've had a lot of folks become concerned with transistors
that got "rather warm" but without putting some form of
instrumentation on the device and then accounting for
thermal resistances in the heat-energy transfer path,
"rather warm" is a rather loose quantification term.
There are instances where the surface temperature of
a power device can get up to "sizzle-spit" temperatures
and still be within operating limits. So if your finger-test
of the device did not send you looking for the burn
ointment, then there's a high probability that the
transistor as installed and operated is going to be
okay . . .
----> I didn't think to measure the mofset temp, but it definitely didn't
get 'sizzle-spit' hot in my tests. I'm sure it could if the switch
were
held long enough. I'll measure temps at my next opportunity.
-----
I also plan to build the Electronic CB circuit. When it was published, Bob's
said to wait until others had a chance to review and comment before
building, so I haven't begun that process yet.
Go ahead an 'brass-board' it if you can. I'm still to tied
up with table saws and paint brushes to spend time at
the bench.
Do you have access to a 'scope? It would be interesting
to fine-tune/verify the value of the capacitor to make the
circuit trip in 200-500 milliseconds after the
green light comes on.
----> I will do that, but it will be a little while before I can get to it.
Work and other commitments definitely get in the way of the fun
stuff.
I don't have a 'scope, but may be able to find one in my EAA
chapter.
----
Thanks for your help in the development effort.
Bob . . .
----> I'm the one who is the recipient of YOUR work :-)
Dennis
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <nuckolls.bob(at)aeroelectric.com> |
| Subject: | Re: RE: IVO Prop Motor Current Limiter and Electronic |
CB
At 08:13 PM 5/9/2010, you wrote:
>
>
> Thanks for your help in the development effort.
>
> Bob . . .
>
>----> I'm the one who is the recipient of YOUR work :-)
>
> Dennis
We all have a part to play. I can plant seeds but may not
have the time to explore their value. If folks like you
can pick up the ball and advance it down-field, then
value has been added. Ultimately, we wish that others
will benefit from the sum total of everyone's start-
up efforts.
THAT is how the gathering of simple-ideas gets
vetted as a recipe for success. Folks on the List
may recall numerous conversations in the past where a
particular design philosophy was the target of vociferous
bashing . . . while thousands of examples had been
flying and performing as expected for two decades.
What we do here may flop. It may be a ho-hum success.
It may provide the idea-seeds for yet another quantum
jump in capability or utility. But seeds never planted,
nurtured and harvested will never reveal their value.
Bob . . .
________________________________________________________________________________
| From: | "John Volkober" <jvolkober(at)comcast.net> |
| Subject: | Electric Boost Pump & Primer Switching |
This is my first post, so here we go.
I want to have a single switch that controls my electric fuel pump and
also
allows me to activate my primer solenoid. The diagram below is my idea
of
on how this should work. I am using a S700-51 switch. In the first
position, the electric fuel, pump in off. In the second position, the
fuel
pump is on. In the third position, a momentary position, both the fuel
pump
and the primer solenoid are on activating the primer. Will this work?
Is
there a another approach I should consider?
John Volkober
________________________________________________________________________________
| Subject: | Re: IVO Prop Motor Current Limiter and Electronic CB |
| From: | "tomcostanza" <Tom(at)CostanzaAndAssociates.com> |
> What we do here may flop. It may be a ho-hum success.
> It may provide the idea-seeds for yet another quantum
> jump in capability or utility. But seeds never planted,
> nurtured and harvested will never reveal their value.
>
> Bob . . .
Thomas Edison is reported to have said after 8000 failures making a storage battery.
"Well, at least we know 8000 things that don't work."
So, IMHO, even a "flop" can be a success if it shows us what not to do.
Clear skies,
Tom Costanza
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=297241#297241
________________________________________________________________________________
| Subject: | Re: Electric Boost Pump & Primer Switching |
| From: | "user9253" <fran4sew(at)banyanol.com> |
The circuit looks like it will work as planned. A small diode across the relay
coil (with the arrow pointing towards positive) will help to prolong the switch
life.
Joe
--------
Joe Gores
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=297243#297243
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <nuckolls.bob(at)aeroelectric.com> |
| Subject: | Re: IVO Prop Motor Current Limiter and Electronic |
CB
>Thomas Edison is reported to have said after 8000 failures making a
>storage battery.
>"Well, at least we know 8000 things that don't work."
Charles Kettering's crew did over 10000 experiments searching
for the economical and effective anti-knock additive for
gasoline.
>So, IMHO, even a "flop" can be a success if it shows us what not to do.
Exactly. There's a new restaurant endeavor spinning up
in a small town near Medicine Lodge. The guy doing it
is a craftsman and probably a pretty good cook. His
efforts so far in getting his facility ready are
impressive (and expensive). But he's never run a
restaurant before nor built an efficient commercial
kitchen. I'm arranging for my son (14+ years in
a host of business and facilities) to meet him. Not
so much to tell him WHAT to do but to assist in
steering him around things that are proven no-nos.
A meeting of experienced minds with long histories
of both successes and failures is the shortest path
to new recipes for success. Everyone from the architect
to the folks who come to collect the trash have an
important role to play.
Bob . . .
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <nuckolls.bob(at)aeroelectric.com> |
| Subject: | Re: RE: IVO Prop Motor Current Limiter and Electron |
ic CB
At 09:11 PM 5/9/2010, you wrote:
>Thanks guys for experimenting in this area.... I have been through 1
>Ivo motor so far and the current one is showing its age now... I am
>pretty anal about taking care not to drive the motor to its stall
>limit by using my ammeter to show increased amp draw, but this is
>kinda hard to do with my 80 amp alt keeping up with the load and
>masking the higher draw when stalled, or at least approaching it.
>The 'extra' noise from the V-8 up front doesn't help either. .
>
>Tailwinds all..............
Interesting! I wonder if there are others here
on the List who are experiencing less than
stellar motor life on IVO.
When the motor fails, what's gone south?
Brushes, bearings, wires, ?
Bob . . .
________________________________________________________________________________
| From: | Peter Pengilly <peter(at)sportingaero.com> |
| Subject: | Busbar voltage from SD-8 |
Hi,
I wonder if I could pick your collective brains? I've just started
flying a One Design that has only an SD-8 to generate power, with a
PC-680 battery. The bus bar voltage is around 15.1 volts (verified on 2
independent instruments). I realise that this is at the top end of the
desirable range, but is it too high? There are very few electrical
services that I can switch on to provide a load to the system. I believe
there is an adjuster screw on the voltage regulator - but that takes a
couples hours of panels unscrewing to access.
So my question is 15.1volts too high for a steady state busbar voltage?
Do I need to do something about it right away or could it wait for 5 hours?
Regards, Peter
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <nuckolls.bob(at)aeroelectric.com> |
| Subject: | Re: Busbar voltage from SD-8 |
At 02:31 PM 5/10/2010, you wrote:
>
>
>Hi,
>
>I wonder if I could pick your collective brains? I've just started
>flying a One Design that has only an SD-8 to generate power, with a
>PC-680 battery. The bus bar voltage is around 15.1 volts (verified
>on 2 independent instruments). I realise that this is at the top end
>of the desirable range, but is it too high? There are very few
>electrical services that I can switch on to provide a load to the
>system. I believe there is an adjuster screw on the voltage
>regulator - but that takes a couples hours of panels unscrewing to access.
>
>So my question is 15.1volts too high for a steady state busbar
>voltage? Do I need to do something about it right away or could it
>wait for 5 hours?
It's not a recipe for fast-destruction of the battery . . .
but we'd like to see it lower. 14.6 volts is a good target.
I'd make the adjustment.
Bob . . .
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <nuckolls.bob(at)aeroelectric.com> |
| Subject: | Re: RE: IVO Prop Motor Current Limiter and Electr |
on ic CB
At 05:38 PM 5/10/2010, you wrote:
>My wires are fine... I usually upsize one gauge or so to be safe on
>all my circuits.
I was wondering about wires inside the motor . . . i.e. windings
on the armature . . .
> Brush wear was high in the beginning till the commutator got
> coated with brush material.... First set of brushes lasted about 20
> hours, second set went 80 or so. It is stabilized at around 150
> hours for a set now. The motor just failed at the 50 hour mark, I
> sent it back and Ron @ Ivo exchanged it for a new one, no charge,
> so I am guessing they had a bad batch.
Hmmmm . . . I presume the times quoted are FLIGHT times. I
would guess that this motor runs less than 5% of flight
time. That doesn't speak well of brush wear rates.
Event the smallest brushed PM motors we used to build
at E-M had brush lives in the hundreds of hours which
would translate to thousands of flight hours.
The next time you talk with Ron, suggest to him that I'm willing
to offer what ever might be useful from my experience-base
in this technology to improve on his product's service
life.
Bob . . .
________________________________________________________________________________
| From: | "Bill Schertz" <wschertz(at)comcast.net> |
| Subject: | Re: RE: IVO Prop Motor Current Limiter and Electr |
on ic CB
I may be mistaken, but I thought the Ivo prop had brushes that were rubbing
all the time the prop was turning -- I.e. they transfer power from the
stationary part of the engine to the rotating prop, which has the motor
mounted on it, (which then rotates with the prop).
Bill Schertz
KIS Cruiser #4045
N343BS
Phase I testing
--------------------------------------------------
From: "Robert L. Nuckolls, III" <nuckolls.bob(at)aeroelectric.com>
Sent: Monday, May 10, 2010 7:35 PM
Subject: Re: AeroElectric-List: RE: IVO Prop Motor Current Limiter and
Electr on ic CB
> Hmmmm . . . I presume the times quoted are FLIGHT times. I
> would guess that this motor runs less than 5% of flight
> time. That doesn't speak well of brush wear rates.
>
> Event the smallest brushed PM motors we used to build
> at E-M had brush lives in the hundreds of hours which
> would translate to thousands of flight hours.
>
> The next time you talk with Ron, suggest to him that I'm willing
> to offer what ever might be useful from my experience-base
> in this technology to improve on his product's service
> life.
>
> Bob . . .
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <nuckolls.bob(at)aeroelectric.com> |
| Subject: | re: IVO Prop Motor Current Limiter and Electronic CB |
At 09:05 PM 5/10/2010, you wrote:
>
>I may be mistaken, but I thought the Ivo prop had brushes that were
>rubbing all the time the prop was turning -- I.e. they transfer
>power from the stationary part of the engine to the rotating prop,
>which has the motor mounted on it, (which then rotates with the prop).
Good questions. No doubt there are two sets of brushes.
One that conducts power from the stationary airframe and
rotating pitch motor assembly, a second set of brushes
run on the commutator within the permanent magnet motor.
So I need to expand my own question to ask which of
the two brush sets is demonstrating a service-life
issue.
Bob . . .
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <nuckolls.bob(at)aeroelectric.com> |
| Subject: | Re: IVO Prop System Brushes |
At 04:20 AM 5/11/2010, you wrote:
To clarify things.....
Bob, it is the brushes that transfer the power to the prop motor on
the hub,,, not the actual pitch change motor itself.
THAT is a very difficult set of components to optimize to
design goals. Brushes on alternators run on the smallest possible
diameters and smooth surfaces. Smoothness reduces wear, diameter
controls surface speed under the brushes. Brushes in tiny
motors benefit most from their tiny commutators . . . in spite
of having to run over a segmented surface.
Brushes that carry power to a moving prop hub DO benefit from
smooth surfaces . . . but they run 100% of the time, are exposed
to environmental contaminants, and have high surface speeds. A
de-ice slip ring for a three bladed prop . . .
Emacs!
can be about 10" in diameter and has three slip rings.
Brushes are a high-maintenance item on these systems
too.
When the first motor failed I did discuss this with Ron @ Ivo and he
was insistent not for me to open the motor and do an autopsy on it
but to just send it back. Which I did and he promptly replaced it
back then. I don't know if it tricky to open up, or there is some
proprietary stuff in it he doesn't was people to see or what.
Probably nothing sinister here. The clues that lead to
good failure diagnosis can be subtle . . . they can also
be fragile to the extent that they are destroyed or
missed by someone opening up a device under study
for the first time.
I don't think I've ever encountered a situation where
a supplier was attempting to keep his "dirty laundry"
a secret. I've encountered many instances were well
meaning but unskilled investigators trashed or missed
an important data point during a teardown inspection.
Bob . . .
________________________________________________________________________________
| Subject: | Alternator cooling |
| From: | "jonlaury" <jonlaury(at)impulse.net> |
After scouring the archives and only one post on topic, I come to you all with
an Alternator cooling question.
My alternators are driven off a spur gear and hence turn opposite to their intended
direction. I've built fiberglass "caps" with blast tubes over the diode plate
end of the alternators to try to keep them cool, but they haven't been run
yet to see if the cooling is adequate.
Has anyone else dealt with this?
Thanks,
John
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=297365#297365
________________________________________________________________________________
| Subject: | Shunt/Hall Sensor placement |
| From: | "jonlaury" <jonlaury(at)impulse.net> |
In Z-13, I would like to place a Hall Sensor for the AUX Alternator between the
battery contactor and the Batt Bus to locate it in the cabin and within it's
recommended ambient temperature operating envelope.
Ditto for the Primary Alternator between the Batt Contactor and the Main Bus.
Any caveats here?
If only one alternator will be online at a time, is there any reason why I should
not run the alternator outputs through just one Hall Sensor?
John
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=297368#297368
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <nuckolls.bob(at)aeroelectric.com> |
| Subject: | Re: Alternator cooling |
At 12:23 PM 5/11/2010, you wrote:
>
>After scouring the archives and only one post on topic, I come to
>you all with an Alternator cooling question.
>
>My alternators are driven off a spur gear and hence turn opposite to
>their intended direction. I've built fiberglass "caps" with blast
>tubes over the diode plate end of the alternators to try to keep
>them cool, but they haven't been run yet to see if the cooling is adequate.
>
>Has anyone else dealt with this?
. . . and if they had, their stories are probably
of limited or no value.
Cooling studies are always accomplished on an installation-
by-installation, model-by-model basis. Then the cooling
studies are blessed as 'golden' because type certificated
aircraft are configuration managed . . . you don't change
ANYTHING without due consideration for unintended consequences.
The ONLY way to ascertain your particular alternator cooling
requirements are to do max angle of climb, full electrical
load cooling studies with thermocouples attached to the
alternator's expected hot spots. After the test data is gathered
and averaged (over 5 or more climb profiles) you then correct the
measured temperatures for hot-day climate conditions.
Failures of alternators on OBAM aircraft due to inadequate
cooling are rare. Major contributors to this rarity are
light loading of alternators, minimum durations for heavy
loads, plenty of air-flow in vicinity of alternator, and
to some degree, luck.
You've obviously 'worried' about it enough to craft
specifically tailored cooling components . . . but
are still unsure. I suspect it's because nobody has repeated
your experiment before and there's no data to share.
So if you're really compelled to know, then you'll
need to fit thermocouples to your alternators bearing
mounts, diode heat sink, and perhaps a couple places
in the stator windings. You'll also need to fit your
airplane with a load bank you can adjust to set up
a nameplate rated load on the alternator along with
instrumentation to read alternator voltage, current,
and thermocouple temperatures. Then you get somebody
to fly with you to do the flight tests.
Once this data is acquired, then YOU will have become
the expert for whether or not your worries were justified
and extra ordinary cooling measures were necessary and
useful.
Bob . . .
>Thanks,
>John
>
>
>Read this topic online here:
>
>http://forums.matronics.com/viewtopic.php?p=297365#297365
>
>
>Checked by AVG - www.avg.com
>05/11/10 01:26:00
Bob . . .
////
(o o)
===========o00o=(_)=o00o========
< Go ahead, make my day . . . >
< show me where I'm wrong. >
================================
________________________________________________________________________________
| Subject: | Re: Shunt/Hall Sensor placement |
| From: | "jonlaury" <jonlaury(at)impulse.net> |
After looking long enough at my proposed HS placement, I can see that one of the
shortcomings is that in the intended location, the sensors would only show alt
throughput to the bus. In the case of the main bus, I could see alt output
to the bus if the main contactor was open. But if it's closed, I'd have no way
of knowing for sure if the alt was functioning at all because battery current
throughput could be masking a dead alternator.
On the batt bus there would be no way to know if the Aux alt was contributing or
not.
RETHINK time.
Sorry for the bother.
J
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=297377#297377
________________________________________________________________________________
| Subject: | Re: Infinity grip |
| From: | "Eric M. Jones" <emjones(at)charter.net> |
Just a note: I saw a stick grip used for custom cars that had four buttons in the
gear shift knob (and probably a battery) that were RF connected to a remote
little switch box. (This might have controlled relays). The idea was to turn
on/off NOX or lights or whatever. Cars usually don't have hollow stick shifters,
so this is an advantage.
I can imagine this might find some use in somebody's aircraft, especially ultralights.
--------
Eric M. Jones
www.PerihelionDesign.com
113 Brentwood Drive
Southbridge, MA 01550
(508) 764-2072
emjones(at)charter.net
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=297416#297416
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <nuckolls.bob(at)aeroelectric.com> |
| Subject: | Re: Shunt/Hall Sensor placement |
At 02:48 PM 5/11/2010, you wrote:
After looking long enough at my proposed HS placement, I can see that
one of the shortcomings is that in the intended location, the sensors
would only show alt throughput to the bus. In the case of the main
bus, I could see alt output to the bus if the main contactor was
open. But if it's closed, I'd have no way of knowing for sure if the
alt was functioning at all because battery current throughput could
be masking a dead alternator.
Check the chapter on batteries in the 'Connection
again . . .
Batteries deliver energy at 12.7 volts and BELOW
while alternators deliver energy at 13.8 volts
and ABOVE.
If an alternator is working, it will have a
positive indication of output current consisting
of aircraft system loads PLUS anything the battery
is asking for in order to replenish a discharge.
Alternators mask dead batteries . . . but batteries
don't mask anything.
Further if the alternator is working, then the bus
voltage is high enough to keep low voltage warning
lights out which are calibrated at 13.0 volts.
On the batt bus there would be no way to know if the Aux alt was
contributing or not.
Same principals apply for both alternators.
Bob . . .
________________________________________________________________________________
| From: | "Jef Vervoort" <jef.vervoortw(at)telenet.be> |
| Subject: | Bussmann fuse blocks |
Does anyone know if this company is still in business:
http://www.mihdirect.biz/
My emails are without reply.
Does anyone know of another source for these fuse blocks, to be mounted in
the main panel of an RV9 ?
Jef Vervoort
________________________________________________________________________________
| Subject: | Re: Bussmann fuse blocks |
| From: | Ken Howell <cfi1513840(at)gmail.com> |
http://www.steinair.com/fuseblocks.htm
On Wed, May 12, 2010 at 5:26 AM, Jef Vervoort wrote:
> Does anyone know if this company is still in business:
> http://www.mihdirect.biz/
>
> My emails are without reply.
>
>
> Does anyone know of another source for these fuse blocks, to be mounted in
> the main panel of an RV9 ?
>
>
> Jef Vervoort
>
> *
>
> *
>
>
________________________________________________________________________________
| From: | Chris Stone <rv8iator(at)earthlink.net> |
| Subject: | Bussmann fuse blocks |
Jef...
All of the Bussman fuse products are available from Waytek.
Chris Stone
RV-8 OR
http://order.waytekwire.com/products2/M50/140/350/250/1/ATO/ATC%20Fuse%20Blocks/Blade%20Fuses%20And%20Accessories/Circuit%20Protection/
Does anyone know if this company is still in
business: http://www.mihdirect.biz/
My emails are without reply.
Does anyone know of another source for these fuse
blocks, to be mounted in the main panel of an RV9 ?
Jef Vervoort
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <nuckolls.bob(at)aeroelectric.com> |
| Subject: | Re: IVO Prop System Brushes |
I can see your thoughts on a lay person dissambling a componant only
to destroy any evidence to use to explain that failure.... I would
like to think I am capable of exceeding the lay persons ability of that task.
Sure, but IVO probably didn't know that. Further,
given that they probably knew more about their
product's design, development and field history,
it seems likely that they are the most qualified
to do failure analysis . . . presuming that their
grasp on the simple-ideas and critical thinking
was up to the task.
I've always desired that field failures of my
products be returned to me for analysis . . .
irrespective of the $time$, talents and resources
of individuals who discovered the failure.
At least for the FIRST time. As you are no doubt
aware, failures arise from a host of stresses
impressed upon weaknesses. The best understanding
of a product's overall performance comes from
a central repository of all data points. This
is best kept with the honorable manufacturer.
However, second and subsequent failures of the
same nature are up for grabs. For a single customer
or some small cluster of customers to experience
the same failure suggests a high-risk stress/weakness
couple that would probably benefit from analysis
by many.
I wasn't suggesting that you were not qualified
or even within your rights as owner of a piece of
failed hardware to do with it as you wish. But
from the perspective of one who has been intimately
attached to dozens of products from conception all
the way through development, qualification, manufacturing,
evolution of design and decades of field service
history, I can empathize with IVO's desire for
conducting their own failure investigation.
I would like to share my thoughts on the first motors failure; My
application is unique in that I am transferring ALOT of horsepower
through the Ivo prop and its related componants. I also started with
the largest diameter blades Ivo offered, 84". My first 25 hours of
test flights were using the Magnum Paddle series blades too and they
are substantially bigger and stiffer then the regular magnum blades.
My guess is the increased forces needed to twist those blades took
out the motor, even though Ron at Ivo knew and sold me that set up.
Hey,,, we are experimenting here and both Ron and I may have learned
something by my initial failure. He is a real nice guy too.
I suspect he is also honorable and that your
joint efforts will do much to advance the value
of his products.
By the lack of others responding of their motors failing my gut
feeling as of this morning is that my 84" paddle blades hurt the
motor, not a inherent design flaw. I never suggested something
sinister, sorry it seemed to come across that way.
Not a problem . . . and it wasn't intended to be
an accusation . . . only an observation based on
my own experiences and intended for 1800 others
who read this List. It's all too easy . . . and
too common for innocuous assertions to morph in
directions that the speaker never intended.
In closing I truly want to say THANK YOU for sharing your vast
knowledge of electrical experiences throughout the years. I for one
have gained a ton from it.
Its a two way street. I AM THANKFUL that the List
offers me opportunity and a reason to be
both curious and constructively critical of
the collections of simple-ideas that drive
performance and value of our airplanes.
I agree with your impressions of the IVO concept
for prop-pitch management. It's a novel idea with
a VERY low parts count but comes with a new set
of challenges. The FORCES involved are, shall we
say, significant? First you have to build a blade
that will survive and perform it's intended task
while still being flexible enough to allow this
pitch-adjusting philosophy to be applied. At the
same time, you need a mechanism that can not only
produce those forces in a controlled fashion but
be able to HOLD against those forces while
vigorously thrashing the air with an energetic
engine.
Achieving the combination of features that meets
design goals while remaining free of hazardous
failure is no simple task. Anything we can do to
be helpful in refining those processes seems
a useful and valuable thing to do. It may
be that a change of gear reduction for the larger
propellers would reduce stresses on the motor.
His product may also be a candidate for a
brushless motor design. Brushless motors can
operate with VERY fast design points and get
a whole lot more horsepower from a small
package. The brushless technology is
so prevalent that prices are now a fraction
of what they were 20 years ago. Further,
the electronics associated with brushless
motor drives is easily integrated into
sophisticated controllers that would limit
both current spikes and servoing pitch for
constant speed operation.
Bob . . .
________________________________________________________________________________
| From: | Mike Welch <mdnanwelch7(at)hotmail.com> |
| Subject: | Ivo motor current limiter design |
Bob=2C group=2C
I just ordered the components for the solid state Ivo current limiter tha
t Bob drew up for us.
Hopefully=2C I'll get it built in a couple of weeks=2C and begin testing.
I'm sure every motor/prop is a little bit different=2C so I got a few ext
ra .1 and .2 ohm resistors for fine tuning.
I hope I'm not too off base and abusing Bob's design goals=2C but I also
bought a 3 position rotary switch=2C with the intent of locating it in conj
unction of the .1 & .2 ohm resistors. My intension is to adjust the resist
ance readings of the three-position switch to show a 2-3 amp limit=2C a 5-6
amp limit=2C and an 8-9 amp limit indication.
I hope this isn't total heresy. Any criticism=2C BTW=2C will be duly not
ed and appreciated!!!
A special "thanks" to Bob for designing this circuit.
Mike Welch
_________________________________________________________________
Hotmail has tools for the New Busy. Search=2C chat and e-mail from your inb
ox.
http://www.windowslive.com/campaign/thenewbusy?ocid=PID28326::T:WLMTAGL:O
N:WL:en-US:WM_HMP:042010_1
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <nuckolls.bob(at)aeroelectric.com> |
| Subject: | Re: Ivo motor current limiter design |
At 11:04 AM 5/12/2010, you wrote:
Bob, group,
I just ordered the components for the solid state Ivo current
limiter that Bob drew up for us.
Hopefully, I'll get it built in a couple of weeks, and begin
testing. I'm sure every motor/prop is a little bit different, so I
got a few extra .1 and .2 ohm resistors for fine tuning.
I hope I'm not too off base and abusing Bob's design goals, but I
also bought a 3 position rotary switch, with the intent of locating
it in conjunction of the .1 & .2 ohm resistors. My intension is to
adjust the resistance readings of the three-position switch to show a
2-3 amp limit, a 5-6 amp limit, and an 8-9 amp limit indication.
I hope this isn't total heresy. Any criticism, BTW, will be duly
noted and appreciated!!!
The 'problem' with using wire and moving parts
to switch low value resistors (under 1 ohm) is that
the compoents and materials used will add 'significant'
resistance to the devices being switched. Another
thing to consider is the current rating of the
switch. A significant portion of the total motor
current flows in the switch.
Note that the term 'significant' is not quantified
and what you propose is probably useful for the
experiment. But pending observations during the
experiment you'll no doubt want to fine tune
the final resistance values and eliminate the
switch.
My personal favorite "switch" for low resistance
experiments is the soldering iron. I'd tack-solder
the parallel tuning resistors onto the leads of
the permanently installed resistor.
Thanks for helping out.
Bob . . .
________________________________________________________________________________
| Subject: | Re: Shunt/Hall Sensor placement |
| From: | "jonlaury" <jonlaury(at)impulse.net> |
nuckolls.bob(at)aeroelect wrote:
> At 02:48 PM 5/11/2010, you wrote:
>
> If an alternator is working, it will have a
> positive indication of output current consisting
> of aircraft system loads PLUS anything the battery
> is asking for in order to replenish a discharge.
> Alternators mask dead batteries . . . but batteries
> don't mask anything.
>
I re-read CH2 on Batteries, but it seems that with the sensor on the contactor-main
bus leg, the sensor would only see the current(amps) going through that leg
to the main bus. The bus voltage would show up on the voltmeter indicating
alternator condition, but I don't see how the HS could detect current going to
the battery if it is located on a branch of the system.
So I'm happy that I can at least verify that the alternator is working with the
sensor inside the cabin, but it seems that if I want to know how hard, I will
need another sensor at the alternator, or use a shunt per Z-13 and forget the
hall sensor.
J
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=297528#297528
________________________________________________________________________________
| From: | Peter Pengilly <peter(at)sportingaero.com> |
| Subject: | Strange radio transmit problem - any suggestions? |
Hi,
I have a Becker AR4201 radio in my One Design
<http://www.glosterairparts.co.uk/OneDesignRebuild8.htm> that I have
just started flying (2 hours on the tacho). Initially the radio worked
great (after I got the mike jack wiring correct - there's always one
bozo moment in any project). Halfway through the 2nd flight the transmit
quit - receive was still good. Plugging in another headset on the ground
and the transmit worked OK.
A couple of days later I pushed the aeroplane out for another flight and
no transmit at all. Carrier wave is being transmitted but no modulation
(and so side tone in my headset). After trying to figure it out for an
hour I put it back together and went flying, still with carrier wave
only. After a while I called a local tower (119.0) - loud and clear.
Returned to my field (124.1) to the same problem - carrier wave only.
What is going on!!! :-(
I have not been able to test further - but I need to step through the
frequency range and find out which freqs work and which do not. This is
a very simple airplane with no intercom, headset connected directly to
the radio. Receive is good all the time, on all freqs tried so far.
Radio shows the transmit arrow whenever the PTT is pushed, and puts out
carrier wave on 124.1. Why is it modulating on some freqs and not
others? Headset works in other aircraft (have tried 3 so far with same
results).
Does anyone have any idea about what is going on?
Any suggestions gratefully received.
Peter
________________________________________________________________________________
| From: | "David LLoyd" <skywagon(at)charter.net> |
| Subject: | Re: Strange radio transmit problem - any suggestions? |
Peter,
>From your description...no modulation is happening. Kinda' points to
the microphone cartridge or wiring in your headset is randomly
malfunctioning. Since you can plug another headset in and all works
well, it points to the mike subassembly in your headset. The wiring
inside most sets is really tiny stuff. Maybe the wire has broken inside
the insulation and makes contact only when your head or mike boom is in
a certain position and then, the wire opens in other positions. Check
it closely and carefully flex the wiring and see if you can find it.
Using an ohm-meter is probably the easiest tool to see if a break is
present.
If the mike cartridge is bad, the manufacturer has to send you a new one
April 21, 2010 - May 12, 2010
AeroElectric-Archive.digest.vol-jm