Today's Message Index:
----------------------
1. 05:03 AM - Re: Facet pumps: Energy vs. Flow (user9253)
2. 06:25 AM - Re: Re: Facet pumps: Energy vs. Flow (BobsV35B@aol.com)
3. 07:27 AM - Re: Re: Facet pumps: Energy vs. Flow (Robert L. Nuckolls, III)
4. 07:58 AM - Re: Re: Designing a circuit question (Robert L. Nuckolls, III)
5. 08:40 AM - Re: Re: Facet pumps: Energy vs. Flow (BobsV35B@aol.com)
6. 08:48 AM - High fuel pressure (jerry2dt@aol.com)
7. 08:49 AM - Re: Facet pumps: Energy vs. Flow (John Burnaby)
8. 08:56 AM - Future of general aviation (Robert L. Nuckolls, III)
9. 09:04 AM - Re: High fuel pressure (Robert L. Nuckolls, III)
10. 09:45 AM - Re: High fuel pressure (Doug Ilg)
11. 09:52 AM - Re: High fuel pressure (Bob Verwey)
12. 10:40 AM - Re: High fuel pressure (Sheldon Olesen)
13. 10:46 AM - Surface temperature sensor ()
14. 11:41 AM - Re: Re: Designing a circuit question (Mike Welch)
15. 12:53 PM - Battery replacement in Garmin 3 pilot (mike gamble)
16. 01:12 PM - Re: Surface temperature sensor (rampil)
17. 02:04 PM - Re: Re: Surface temperature sensor ()
18. 02:28 PM - Re: Accurate Altitude and Airspeed (The Kuffels)
19. 04:21 PM - Re: Surface temperature sensor (rampil)
20. 04:42 PM - Diode confusion (Lincoln Keill)
21. 05:05 PM - Re: Diode confusion (Harley)
22. 05:07 PM - Re: High fuel pressure (Tim Andres)
23. 05:42 PM - Re: Re: Designing a circuit question (Dennis & Anne Glaeser)
24. 06:33 PM - Re: Diode confusion (Robert Sultzbach)
25. 06:43 PM - Re: Diode confusion (Robert Sultzbach)
26. 06:51 PM - Re: Re: Re: Designing a circuit question (Mike Welch)
27. 08:07 PM - Re: S704-1 on Hot Side of Firewall? (Noah)
28. 08:08 PM - Re: The Miracle Whip series antennae (Speedy11@aol.com)
29. 08:15 PM - Alternator field feed - fuse vs. fusible link (Noah)
30. 08:39 PM - Circuit Diagram (rckol)
31. 09:36 PM - Re: Alternator field feed - fuse vs. fusible link ()
32. 10:08 PM - Re: Future of general aviation (Paul Kuntz)
33. 10:58 PM - Re: Re: Surface temperature sensor (Robert L. Nuckolls, III)
34. 11:06 PM - Re: Re: Designing a circuit question (Robert L. Nuckolls, III)
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Subject: | Re: Facet pumps: Energy vs. Flow |
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
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Subject: | Re: Facet pumps: Energy vs. Flow |
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 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!
<G>
Happy Skies,
Old Bob
In a message dated 4/21/2010 7:04:31 A.M. Central Daylight Time,
fran4sew@banyanol.com writes:
--> AeroElectric-List message posted by: "user9253"
<fran4sew@banyanol.com>
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
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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 . . .
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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 . . .
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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@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 . . .
Message 6
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Subject: | High fuel pressure |
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
-----Original Message-----
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Sent: Tue, Apr 20, 2010 11:55 pm
Subject: AeroElectric-List Digest: 12 Msgs - 04/20/10
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Today's Message Index:
----------------------
1. 04:40 AM - Re: Facet pumps: Energy vs. Flow (Bill Boyd)
2. 05:43 AM - Re: Facet pumps: Energy vs. Flow (rampil)
3. 05:48 AM - Re: Facet pumps: Energy vs. Flow (BobsV35B@aol.com)
4. 06:09 AM - Re: Re: Facet pumps: Energy vs. Flow (Jon Finley)
5. 07:51 AM - Re: (BobsV35B@aol.com)
6. 07:58 AM - Re: Re: Facet pumps: Energy vs. Flow (BobsV35B@aol.com
)
7. 10:35 AM - Re: Facet pumps: Energy vs. Flow (Mike Welch)
8. 11:05 AM - Re: Re: Facet pumps: Energy vs. Flow (BobsV35B@aol.com
)
9. 01:53 PM - Re: switch breaker on ALT field (rckol)
10. 03:38 PM - S704-1 on Hot Side of Firewall? (Noah)
11. 08:30 PM - Re: S704-1 on Hot Side of Firewall? (Robert L. Nuckoll
s,
III)
12. 08:36 PM - Re: Re: switch breaker on ALT field (Robert L. Nuckoll
s,
III)
________________________________ Message 1 _____________________________
________
Time: 04:40:20 AM PST US
Subject: Re: AeroElectric-List: Facet pumps: Energy vs. Flow
From: Bill Boyd <sportav8r@gmail.com>
How about some filtering on the "input" line of the ammeter? If we're
looking at constant-amplitude square wave current pulses of varying
frequency, a capacitive filter to perform an "integral" function might giv
e
you an average-current-over-time measurement that closely matches the
frequency and therefore the load on the pump. In practice, I am not sure
from listening to my Facet pump all these years how much the frequency
changes as a function of load. There is a sound change as it self-primes
when I first hit it before engine-start.
Just a thought. I had to do the pneumatic equivalent (expansion chamber
plus input restrictor) to keep my manifold pressure digital readout from
jumping all around in an un-readable fashion. A little RC pi or L network
might do what you need.
Bill B.
On Mon, Apr 19, 2010 at 9:56 PM, Charlie England <ceengland@bellsouth.net>
wrote:
> ceengland@bellsouth.net>
>
> Certificated. Bummer.
>
> If you think you can legally use current sensing, have you tried a
> restricter in the pump's output to see if it will raise the current enou
gh
> to be measurable vs the no-flow state?
>
> On 4/19/2010 6:16 PM, BobsV35B@aol.com wrote:
>
>> Good Morning Charlie,
>> Those units by Pillar Point Electronics look very promising. As I said
a
>> couple of messages back, I need something that can be used on a normall
y
>> certificated aircraft. Not sure about the PPE product, but I am checkin
g
>> into it.
>> Thanks for the comment.
>> Happy Skies,
>> Old Bob
>> In a message dated 4/19/2010 4:50:49 P.M. Central Daylight Time,
>> ceengland@bellsouth.net writes:
>>
>> <ceengland@bellsouth.net>
>>
>> On 4/19/2010 3:03 PM, ROGER & JEAN CURTIS wrote:
>> >
>> > To me, they look and sound just like the ones that were used
>> > on those Ford gasoline fired heaters back in the thirties. But
>> my memory
>> > could be fooling me.
>> >
>> > Those were probably the Stewart Warner or Bendix pumps.
>> > Whadda Ya Think?
>> >
>> > If so. does that mean I need to monitor the frequency some
>> > how?
>> >
>> > This is getting complicated,. No wonder nobody does it!
>> >
>> > Happy Skies,
>> >
>> > Old Bob
>> >
>> > I am not sure of the application here, but I
>> > believe that there should be a significant pressure drop on the
>> output of
>> > the pump, when there is no longer any fuel. This being the
>> case, perhaps
>> > you could use a pressure switch, similar to what is used to
>> monitor engine
>> > oil pressure and turn on the hobbs meter, on some aircraft. You
>> would need
>> > to check the pressure differential between pumping fuel and
>> empty tank
>> > pumping, and use a switch midway between. This would be a
>> normally closed
>> > switch which would open when there is fuel flow and close, to
>> turn on the
>> > light when there is no more fuel to pump.
>> >
>> > Not sure if this is a viable option for your
>> > application, but might work, and is very simple. (I especially li
ke
>> > simple:-)
>> >
>> > Roger
>> >
>> If you're using it as a transfer pump, there won't be a lot of
>> pressure
>> since it will be just the 'head' from one tank to the other. Often
no
>> more than a few inches of rise, plus the resistance of the tubing.
>>
>> How about one of the sensing devices using light to detect the
>> presence
>> of liquid? I bought a couple several years ago, intending to use
>> them to
>> monitor end-of-transfer from my aux tanks, then forgot to install
>> them.... They mount in a single hole & have a cone shaped plexi
>> tip. An
>> LED shines out through the plexi; presence/absence of liquid
>> changes the
>> light reflected back into the photocell in the same housing, changin
g
>> the state of the sense line.
>>
>> If that interests you, I'll try to locate the name of the device &
a
>> source for you.
>>
>> Charlie
>>
>> *
>>
>>
>> *
>>
>
>
________________________________ Message 2 _____________________________
________
Time: 05:43:01 AM PST US
Subject: AeroElectric-List: Re: Facet pumps: Energy vs. Flow
From: "rampil" <ira.rampil@gmail.com>
Good engineering principles favor measuring the actual parameter
you want, rather than a surrogate, especially when there is no
reliable one-to-one mapping of one to the other.
In the case of current draw, for example, overheating the coil or dirt
in the mechanism will probably change the current draw
Pressure downstream would depend on where the fill hose enters the
downstream tank, if at the bottom, or at a positive hydrostatic head, the
pressure downstream of the pump will stay positive while there is fuel
in the tank.
What about measuring fuel level in the feeding tank, is not that what you
really want to make a decision with? When it reads zero, stop pumping?
--------
Ira N224XS
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=294942#294942
________________________________ Message 3 _____________________________
________
Time: 05:48:55 AM PST US
From: BobsV35B@aol.com
Subject: Re: AeroElectric-List: Facet pumps: Energy vs. Flow
Good Morning Bill,
Wow!
It appears that any suitable current measuring device will be a lot more
complex than my feeble brain can comprehend.
Thanks to you and all the others that have contributed to my on going
education.
In any case, it does seem that a few breadboard experiments are in order.
Happy Skies,
Old Bob
In a message dated 4/20/2010 6:41:53 A.M. Central Daylight Time,
sportav8r@gmail.com writes:
How about some filtering on the "input" line of the ammeter? If we're
looking at constant-amplitude square wave current pulses of varying freque
ncy,
a capacitive filter to perform an "integral" function might give you an
average-current-over-time measurement that closely matches the frequency
and
therefore the load on the pump. In practice, I am not sure from listenin
g
to my Facet pump all these years how much the frequency changes as a
function of load. There is a sound change as it self-primes when I first
hit
it
before engine-start.
Just a thought. I had to do the pneumatic equivalent (expansion chamber
plus input restrictor) to keep my manifold pressure digital readout from
jumping all around in an un-readable fashion. A little RC pi or L network
might do what you need.
Bill B.
On Mon, Apr 19, 2010 at 9:56 PM, Charlie England <_ceengland@bellsouth.net
_
(mailto:ceengland@bellsouth.net) > wrote:
<_ceengland@bellsouth.net_ (mailto:ceengland@bellsouth.net) >
Certificated. Bummer.
If you think you can legally use current sensing, have you tried a
restricter in the pump's output to see if it will raise the current enoug
h to
be
measurable vs the no-flow state?
On 4/19/2010 6:16 PM, _BobsV35B@aol.com_ (mailto:BobsV35B@aol.com) wrote
:
Good Morning Charlie,
Those units by Pillar Point Electronics look very promising. As I said a
couple of messages back, I need something that can be used on a normally
certificated aircraft. Not sure about the PPE product, but I am checking
into
it.
Thanks for the comment.
Happy Skies,
Old Bob
In a message dated 4/19/2010 4:50:49 P.M. Central Daylight Time,
_ceengland@bellsouth.net_ (mailto:ceengland@bellsouth.net) writes:
<_ceengland@bellsouth.net_ (mailto:ceengland@bellsouth.net) >
On 4/19/2010 3:03 PM, ROGER & JEAN CURTIS wrote:
>
> To me, they look and sound just like the ones that were used
> on those Ford gasoline fired heaters back in the thirties. But
my memory
> could be fooling me.
>
> Those were probably the Stewart Warner or Bendix pumps.
> Whadda Ya Think?
>
> If so. does that mean I need to monitor the frequency some
> how?
>
> This is getting complicated,. No wonder nobody does it!
>
> Happy Skies,
>
> Old Bob
>
> I am not sure of the application here, but I
> believe that there should be a significant pressure drop on the
output of
> the pump, when there is no longer any fuel. This being the
case, perhaps
> you could use a pressure switch, similar to what is used to
monitor engine
> oil pressure and turn on the hobbs meter, on some aircraft. You
would need
> to check the pressure differential between pumping fuel and
empty tank
> pumping, and use a switch midway between. This would be a
normally closed
> switch which would open when there is fuel flow and close, to
turn on the
> light when there is no more fuel to pump.
>
> Not sure if this is a viable option for your
> application, but might work, and is very simple. (I especially like
> simple:-)
>
> Roger
>
If you're using it as a transfer pump, there won't be a lot of
pressure
since it will be just the 'head' from one tank to the other. Often no
more than a few inches of rise, plus the resistance of the tubing.
How about one of the sensing devices using light to detect the
presence
of liquid? I bought a couple several years ago, intending to use
them to
monitor end-of-transfer from my aux tanks, then forgot to install
them.... They mount in a single hole & have a cone shaped plexi
tip. An
LED shines out through the plexi; presence/absence of liquid
changes the
light reflected back into the photocell in the same housing, changing
the state of the sense line.
If that interests you, I'll try to locate the name of the device & a
source for you.
Charlie
________________________________ Message 4 _____________________________
________
Time: 06:09:04 AM PST US
Subject: RE: AeroElectric-List: Re: Facet pumps: Energy vs. Flow
From: "Jon Finley" <jon@finleyweb.net>
=0AI find this discussion very interesting and hope for an inexpensive
solu
tion. I really like that Pillar Point flow detector but the price is more
than I'd like to spend.=0A =0AJust to add some data points.... In my
case,
I know the fuel level in the tank but I wish to know when fuel stops being
delivered to that tank so alternate plans can be made. So, a "fuel is not
f
lowing" indicator would add a level of comfort (would be "nice" but certai
n
ly not mandatory since I am currently flying without this).=0A =0AMore
spec
ifically, I have a large main tank from which fuel is pumped into the head
e
r. The header is about 5 gallons (one hour of flight time). I typically
l
eave my transfer pump on all the time. If it were to stop and I didn't no
t
ice (which is likely), I have a warning light that will come on at about
2.
5-3 gallons. That leaves me with about 30 minutes to figure out what to
do
. If I had known immediately, I would have had 60 minutes. Of course, I
h
ave a backup fuel pump which I would immediately switch on. However; it
ca
n take some time before seeing the fuel level start to rise. When dealing
w
ith a 30 minute window, knowing now versus knowing in 5-10 minutes is a bi
g
deal (at least in terms of my stress level - FYI, I live out west were ai
r
ports are frequently more than 30 minutes apart).=0A=0AJon Finley=0A
N314JF
- Q2 - Subaru EJ22=0A[http://www.finleyweb.net/Q2Subaru.aspx] http://www
.fi
nleyweb.net/Q2Subaru.aspx=0A =0A =0A=0A-----Original Message-----
=0AFrom: "
rampil" <ira.rampil@gmail.com>=0ASent: Tuesday, April 20, 2010 6:41am=
0ATo:
aeroelectric-list@matronics.com=0ASubject: AeroElectric-List: Re: Facet
pu
<ira.rampil@gmail.com>=0A=0AGood engineering principles favor measuri
ng th
e actual parameter=0Ayou want, rather than a surrogate, especially when
the
re is no=0Areliable one-to-one mapping of one to the other.=0A=0AIn
the cas
e of current draw, for example, overheating the coil or dirt=0Ain the me
cha
nism will probably change the current draw=0APressure downstream would
depe
nd on where the fill hose enters the =0Adownstream tank, if at the botto
m,
or at a positive hydrostatic head, the =0Apressure downstream of the pum
p w
ill stay positive while there is fuel=0Ain the tank.=0A=0AWhat about
measur
ing fuel level in the feeding tank, is not that what you=0Areally want
to m
ake a decision with? When it reads zero, stop pumping?=0A=0A--------
=0AIra
N224XS=0A=0A=0A=0A=0ARead this topic online here:=0A=0Ahttp:
//forums.matron
================0A=0A=0A=0A
________________________________ Message 5 _____________________________
________
Time: 07:51:11 AM PST US
From: BobsV35B@aol.com
Subject: Re: AeroElectric-List:
Test --- Do Not Archive
In a message dated
________________________________ Message 6 _____________________________
________
Time: 07:58:18 AM PST US
From: BobsV35B@aol.com
Subject: Re: AeroElectric-List: Re: Facet pumps: Energy vs. Flow
Good Morning Ira,
I have what I consider to be relatively good fuel gauges in the tanks, but
find that there is at least a ten to fifteen minute window between where
the gauge says empty and it actually will be dry. I do not wish to turn
the
pump off too soon and have fuel in the tank that has not been used and I
do
not like to run the pump when it is not actually pumping fuel.
It would be very nice to be able to verify the accuracy of the fuel gauge
by noting when the pump stops pumping fuel rather than running the pump
while dry for possibly an extra ten to fifteen minutes every time I utili
ze the
auxiliary fuel tank.
I do have excellent fuel use measuring capability and what I do now is not
e
the fuel burned number when I turn on the pump and shut it off when the
amount of fuel known to be in the tank has been burned.
Nevertheless, it would be nice to know within seconds when the tank has ru
n
dry so that the pump could be turned off.
I really would rather not be running the pump when it is not pumping fuel
.
Happy Skies,
Old Bob
In a message dated 4/20/2010 7:43:50 A.M. Central Daylight Time,
ira.rampil@gmail.com writes:
--> AeroElectric-List message posted by: "rampil" <ira.rampil@gmail.com>
Good engineering principles favor measuring the actual parameter
you want, rather than a surrogate, especially when there is no
reliable one-to-one mapping of one to the other.
In the case of current draw, for example, overheating the coil or dirt
in the mechanism will probably change the current draw
Pressure downstream would depend on where the fill hose enters the
downstream tank, if at the bottom, or at a positive hydrostatic head, the
pressure downstream of the pump will stay positive while there is fuel
in the tank.
What about measuring fuel level in the feeding tank, is not that what you
really want to make a decision with? When it reads zero, stop pumping?
--------
Ira N224XS
________________________________ Message 7 _____________________________
________
Time: 10:35:34 AM PST US
From: Mike Welch <mdnanwelch7@hotmail.com>
Subject: AeroElectric-List: Re: Facet pumps: Energy vs. Flow
Bob=2C
Pardon me for butting in=2C but from my experience with certificated
airp
lanes=2C it is virtually impossible to get a field approval like you're
aft
er.
I used to have a 1961 Cessna 172=2C with an O-300 Continental. On tho
se
hot mid-summer California days (100+)=2C my oil temps got well into the
red
on climbout!! I checked the accuracy of the gauge=2C and it was correc
t!
Therefore=2C I wanted to add an oil cooler to my Cessna 172. It didn'
t c
ome with one=2C but I could get a later model 172 oil cooler to fit. I
sen
t off my Form 337 to the local FSDO=2C and their first reaction was "NO!
"
Their attitude was "if it didn't come with one=2C it doesn't need one!!"
I was irritated (to say the least)=2C and requested an appeal. They
fina
lly relented and said it would be okay. For crying out loud =2C it was
jus
t an oil cooler!! (all certified parts=2C too)
My opinion is=3B there ain't no way you can legally add any kind of pe
rma
nent parts to modify to your fuel pump=2C fuel lines=2C or anything el
se=2C
on a certificated airplane=2C without that approved 337.
Just my opinion.................
Mike Welch
From: BobsV35B@aol.com
Subject: Re: AeroElectric-List: Re: Facet pumps: Energy vs. Flow
Good Morning Ira=2C
I have what I consider to be relatively good fuel gauges in the tanks=2C
bu
t find that there is at least a ten to fifteen minute window between where
the gauge says empty and it actually will be dry. I do not wish to turn th
e
pump off too soon and have fuel in the tank that has not been used and I
d
o not like to run the pump when it is not actually pumping fuel.
It would be very nice to be able to verify the accuracy of the fuel gauge
b
y noting when the pump stops pumping fuel rather than running the pump whi
l
e dry for possibly an extra ten to fifteen minutes every time I utilize th
e
auxiliary fuel tank.
I do have excellent fuel use measuring capability and what I do now is not
e
the fuel burned number when I turn on the pump and shut it off when the
am
ount of fuel known to be in the tank has been burned.
Nevertheless=2C it would be nice to know within seconds when the tank ha
s r
un dry so that the pump could be turned off.
I really would rather not be running the pump when it is not pumping fuel.
Happy Skies=2C
Old Bob
In a message dated 4/20/2010 7:43:50 A.M. Central Daylight Time=2C ira.r
amp
il@gmail.com writes:
Good engineering principles favor measuring the actual parameter
you want=2C rather than a surrogate=2C especially when there is no
reliable one-to-one mapping of one to the other.
In the case of current draw=2C for example=2C overheating the coil or
dirt
in the mechanism will probably change the current draw
Pressure downstream would depend on where the fill hose enters the
downstream tank=2C if at the bottom=2C or at a positive hydrostatic he
ad=2C
the
pressure downstream of the pump will stay positive while there is fuel
in the tank.
What about measuring fuel level in the feeding tank=2C is not that what
you
really want to make a decision with? When it reads zero=2C stop pumping?
--------
Ira N224XS
_________________________________________________________________
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________________________________ Message 8 _____________________________
________
Time: 11:05:32 AM PST US
From: BobsV35B@aol.com
Subject: Re: AeroElectric-List: Re: Facet pumps: Energy vs. Flow
Good Afternoon Mike,
Believe it or not I do understand your frustration and the problems that
are faced when dealing with the FAA.
It is my opinion that the vast majority of the folks at FAA want to do a
good job, but are so hamstrung with regulations and paper work that it is
easier to just say no.
However, I have had fairly good luck getting local approvals from my
supervising FSDO.
As I think we can all agree, each FSDO is a kingdom unto itself and what
is
easy to get approved at one office may be impossible at another.
Nevertheless, I have gotten several local approvals here locally. I do ho
ld an
A&P
with Inspection Authorization. It does help me know who I should present
the
data to and how the presentation should be made.
In general, if we can think of a way to add something that has no chance
of
interfering with required equipment, the local approval has a better
chance of being approved.
Once again, the FAA has no obligation to ever issue a local approval. In
fact, if an individual inspector does issue the approval, he is doing it
on
his own knowledge and is personally responsible for what happens. In many
ways it is surprising that any FAA inspector ever issues a local approval
.
He/she has no obligation to do so. It is just a privilege he has been
accorded. Failure to do so does not hurt his career at all, but making a
dumb
approval could end his career.
Happy Skies,
Old Bob
In a message dated 4/20/2010 12:37:05 P.M. Central Daylight Time,
mdnanwelch7@hotmail.com writes:
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 ho
t
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 com
e
with one, but I could get a later model 172 oil cooler to fit. I sent of
f
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 finall
y
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.................
Mike Welch
________________________________ Message 9 _____________________________
________
Time: 01:53:26 PM PST US
Subject: AeroElectric-List: Re: switch breaker on ALT field
From: "rckol" <rckol@kaehlers.com>
Switch breakers will function for this application.
I have read conflicting reports about the long term reliability of these.
Some
folks end up tearing them out because they don't hold up and others have
no
trouble
with them. Sorry, I don't have any brand specific recommendations. I
am not going to use them.
Dick
--------
rck
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=295024#295024
________________________________ Message 10 ____________________________
________
Time: 03:38:33 PM PST US
Subject: AeroElectric-List: S704-1 on Hot Side of Firewall?
From: "Noah" <sgninc@cox.net>
I requested the spec sheet for the S704-1 relay from B&C, and it is a Tyco
T9A
with an operating temp limit of 85C (185F). This seems a bit low for moun
ting
in the engine compartment on the firewall. where I had been planning to mo
unt
it. I called B&C to ask them if they recommended mounting these in the en
gine
compartment and the gentleman I spoke with was not sure - he recommended
a post
here.
Anybody know what the firewall temps can climb to?? Anybody mounted one
of
these
firewall forward in an RV and had problems? Or had it last 2000 hours wit
hout
issue??
--------
Highest Regards,
Noah Forden
RV-7A
Rhode Island
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=295030#295030
________________________________ Message 11 ____________________________
________
Time: 08:30:35 PM PST US
From: "Robert L. Nuckolls, III" <nuckolls.bob@aeroelectric.com>
Subject: Re: AeroElectric-List: S704-1 on Hot Side of Firewall?
At 05:36 PM 4/20/2010, you wrote:
>
>I requested the spec sheet for the S704-1 relay from B&C, and it is
>a Tyco T9A with an operating temp limit of 85C (185F). This seems a
>bit low for mounting in the engine compartment on the firewall.
>where I had been planning to mount it. I called B&C to ask them if
>they recommended mounting these in the engine compartment and the
>gentleman I spoke with was not sure - he recommended a post here.
>
>Anybody know what the firewall temps can climb to?? Anybody mounted
>one of these firewall forward in an RV and had problems? Or had it
>last 2000 hours without issue??
It will be fine. These devices and their close
cousins are used under the hood of motor vehicles
and they're fine.
The various companies I've worked for have done
numerous studies of temperature under the cowl
and found that nothing gets really all that hot
as long as it's not exposed to direct infra-red
radiation from stacks (particularly turbochargers).
I've seen some RG battery cases melted because they
were too close to exhaust pipes.
Bob . . .
________________________________ Message 12 ____________________________
________
Time: 08:36:06 PM PST US
From: "Robert L. Nuckolls, III" <nuckolls.bob@aeroelectric.com>
Subject: Re: AeroElectric-List: Re: switch breaker on ALT field
At 03:50 PM 4/20/2010, you wrote:
>
>Switch breakers will function for this application.
>
>I have read conflicting reports about the long term reliability of
>these. Some folks end up tearing them out because they don't hold
>up and others have no trouble with them. Sorry, I don't have any
>brand specific recommendations. I am not going to use them.
The mil-qualified sw/breakers are fine. Actually, the
P&B W31 series are reasonably decent too. There's about
80K in service in Bonanzas and Barons since way back
when . . . and yes, a few have failed in a way that
put smoke in the cockpit . . . but those were the 30A
devices that control electric prop de-ice.
Obviously, you can't get the features in single
switches of any kind that are offered in the progressive-
transfer 2-pole toggles (2-10, 2-50, 2-70) but if your
design goals don't require this feature, then the
single switches will do.
Now, having said that, I'm not sure I'd recommend
the W31 used upstream of a crowbar ov protection system
that I designed. I've not studied the trip dynamics of
this device in that application. The miniature TI/Klixon
style breakers have been paired with our crowbar ov
systems by the thousands with good service histories.
Bob . . .
========================
===========
========================
===========
========================
===========
========================
===========
Message 7
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|
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".
Message 8
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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 . . .
Message 9
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|
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 . . .
Message 10
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|
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@aol.com" <jerry2dt@aol.com>=0A>To
: aeroelectric-list@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>
Message 11
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Subject: | Re: High fuel pressure |
Can only be a sender unit problem IMHO...pump would not be able to make this
kind of pressure.
regards
Bob Verwey
On 21 April 2010 17:46, <jerry2dt@aol.com> 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.
>
> Thanks all,
>
> Jerry Cochran
>
>
> -----Original Message-----
> From: AeroElectric-List Digest Server <aeroelectric-list@matronics.com>
> To: AeroElectric-List Digest List <aeroelectric-list-digest@matronics.com>
> Sent: Tue, Apr 20, 2010 11:55 pm
> Subject: AeroElectric-List Digest: 12 Msgs - 04/20/10
>
> *
>
>
> =================================================
>
> Online Versions of Today's List Digest Archive
>
> =================================================
>
>
> Today's complete AeroElectric-List Digest can also be found in either of the
>
> two Web Links listed below. The .html file includes the Digest formatted
>
> in HTML for viewing with a web browser and features Hyperlinked Indexes
>
> and Message Navigation. The .txt file includes the plain ASCII version
>
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>
> such as Notepad or with a web browser.
>
>
> HTML Version:
>
>
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>
>
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>
>
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> EMail Version of Today's List Digest Archive
>
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>
>
> ----------------------------------------------------------
>
> AeroElectric-List Digest Archive
>
> ---
>
> Total Messages Posted Tue 04/20/10: 12
>
> ----------------------------------------------------------
>
>
> Today's Message Index:
>
> ----------------------
>
>
> 1. 04:40 AM - Re: Facet pumps: Energy vs. Flow (Bill Boyd)
>
> 2. 05:43 AM - Re: Facet pumps: Energy vs. Flow (rampil)
>
> 3. 05:48 AM - Re: Facet pumps: Energy vs. Flow (BobsV35B@aol.com)
>
> 4. 06:09 AM - Re: Re: Facet pumps: Energy vs. Flow (Jon Finley)
>
> 5. 07:51 AM - Re: (BobsV35B@aol.com)
>
> 6. 07:58 AM - Re: Re: Facet pumps: Energy vs. Flow (BobsV35B@aol.com)
>
> 7. 10:35 AM - Re: Facet pumps: Energy vs. Flow (Mike Welch)
>
> 8. 11:05 AM - Re: Re: Facet pumps: Energy vs. Flow (BobsV35B@aol.com)
>
> 9. 01:53 PM - Re: switch breaker on ALT field (rckol)
>
> 10. 03:38 PM - S704-1 on Hot Side of Firewall? (Noah)
>
> 11. 08:30 PM - Re: S704-1 on Hot Side of Firewall? (Robert L. Nuckolls,
>
> III)
>
> 12. 08:36 PM - Re: Re: switch breaker on ALT field (Robert L. Nuckolls,
>
> III)
>
>
> ________________________________ Message 1 _____________________________________
>
>
> Time: 04:40:20 AM PST US
>
> Subject: Re: AeroElectric-List: Facet pumps: Energy vs. Flow
>
> From: Bill Boyd <sportav8r@gmail.com>
>
>
> How about some filtering on the "input" line of the ammeter? If we're
>
> looking at constant-amplitude square wave current pulses of varying
>
> frequency, a capacitive filter to perform an "integral" function might give
>
> you an average-current-over-time measurement that closely matches the
>
> frequency and therefore the load on the pump. In practice, I am not sure
>
> from listening to my Facet pump all these years how much the frequency
>
> changes as a function of load. There is a sound change as it self-primes
>
> when I first hit it before engine-start.
>
>
> Just a thought. I had to do the pneumatic equivalent (expansion chamber
>
> plus input restrictor) to keep my manifold pressure digital readout from
>
> jumping all around in an un-readable fashion. A little RC pi or L network
>
> might do what you need.
>
>
> Bill B.
>
>
> On Mon, Apr 19, 2010 at 9:56 PM, Charlie England <ceengland@bellsouth.net>wrote:
>
>
> > ceengland@bellsouth.net>
>
> >
>
> > Certificated. Bummer.
>
> >
>
> > If you think you can legally use current sensing, have you tried a
>
> > restricter in the pump's output to see if it will raise the current enough
>
> > to be measurable vs the no-flow state?
>
> >
>
> > On 4/19/2010 6:16 PM, BobsV35B@aol.com wrote:
>
> >
>
> >> Good Morning Charlie,
>
> >> Those units by Pillar Point Electronics look very promising. As I said a
>
> >> couple of messages back, I need something that can be used on a normally
>
> >> certificated aircraft. Not sure about the PPE product, but I am checking
>
> >> into it.
>
> >> Thanks for the comment.
>
> >> Happy Skies,
>
> >> Old Bob
>
> >> In a message dated 4/19/2010 4:50:49 P.M. Central Daylight Time,
>
> >> ceengland@bellsouth.net writes:
>
> >>
>
> >> <ceengland@bellsouth.net>
>
> >>
>
> >> On 4/19/2010 3:03 PM, ROGER & JEAN CURTIS wrote:
>
> >> >
>
> >> > To me, they look and sound just like the ones that were used
>
> >> > on those Ford gasoline fired heaters back in the thirties. But
>
> >> my memory
>
> >> > could be fooling me.
>
> >> >
>
> >> > Those were probably the Stewart Warner or Bendix pumps.
>
> >> > Whadda Ya Think?
>
> >> >
>
> >> > If so. does that mean I need to monitor the frequency some
>
> >> > how?
>
> >> >
>
> >> > This is getting complicated,. No wonder nobody does it!
>
> >> >
>
> >> > Happy Skies,
>
> >> >
>
> >> > Old Bob
>
> >> >
>
> >> > I am not sure of the application here, but I
>
> >> > believe that there should be a significant pressure drop on the
>
> >> output of
>
> >> > the pump, when there is no longer any fuel. This being the
>
> >> case, perhaps
>
> >> > you could use a pressure switch, similar to what is used to
>
> >> monitor engine
>
> >> > oil pressure and turn on the hobbs meter, on some aircraft. You
>
> >> would need
>
> >> > to check the pressure differential between pumping fuel and
>
> >> empty tank
>
> >> > pumping, and use a switch midway between. This would be a
>
> >> normally closed
>
> >> > switch which would open when there is fuel flow and close, to
>
> >> turn on the
>
> >> > light when there is no more fuel to pump.
>
> >> >
>
> >> > Not sure if this is a viable option for your
>
> >> > application, but might work, and is very simple. (I especially like
>
> >> > simple:-)
>
> >> >
>
> >> > Roger
>
> >> >
>
> >> If you're using it as a transfer pump, there won't be a lot of
>
> >> pressure
>
> >> since it will be just the 'head' from one tank to the other. Often no
>
> >> more than a few inches of rise, plus the resistance of the tubing.
>
> >>
>
> >> How about one of the sensing devices using light to detect the
>
> >> presence
>
> >> of liquid? I bought a couple several years ago, intending to use
>
> >> them to
>
> >> monitor end-of-transfer from my aux tanks, then forgot to install
>
> >> them.... They mount in a single hole & have a cone shaped plexi
>
> >> tip. An
>
> >> LED shines out through the plexi; presence/absence of liquid
>
> >> changes the
>
> >> light reflected back into the photocell in the same housing, changing
>
> >> the state of the sense line.
>
> >>
>
> >> If that interests you, I'll try to locate the name of the device & a
>
> >> source for you.
>
> >>
>
> >> Charlie
>
> >>
>
> >> *
>
> >>
>
> >>
>
> >> *
>
> >>
>
> >
>
> >
>
>
> ________________________________ Message 2 _____________________________________
>
>
> Time: 05:43:01 AM PST US
>
> Subject: AeroElectric-List: Re: Facet pumps: Energy vs. Flow
>
> From: "rampil" <ira.rampil@gmail.com>
>
>
> Good engineering principles favor measuring the actual parameter
>
> you want, rather than a surrogate, especially when there is no
>
> reliable one-to-one mapping of one to the other.
>
>
> In the case of current draw, for example, overheating the coil or dirt
>
> in the mechanism will probably change the current draw
>
> Pressure downstream would depend on where the fill hose enters the
>
> downstream tank, if at the bottom, or at a positive hydrostatic head, the
>
> pressure downstream of the pump will stay positive while there is fuel
>
> in the tank.
>
>
> What about measuring fuel level in the feeding tank, is not that what you
>
> really want to make a decision with? When it reads zero, stop pumping?
>
>
> --------
>
> Ira N224XS
>
>
> Read this topic online here:
>
> http://forums.matronics.com/viewtopic.php?p=294942#294942
>
>
> ________________________________ Message 3 _____________________________________
>
>
> Time: 05:48:55 AM PST US
>
> From: BobsV35B@aol.com
>
> Subject: Re: AeroElectric-List: Facet pumps: Energy vs. Flow
>
>
> Good Morning Bill,
>
>
> Wow!
>
>
> It appears that any suitable current measuring device will be a lot more
>
> complex than my feeble brain can comprehend.
>
>
> Thanks to you and all the others that have contributed to my on going
>
> education.
>
>
> In any case, it does seem that a few breadboard experiments are in order.
>
>
> Happy Skies,
>
>
> Old Bob
>
>
> In a message dated 4/20/2010 6:41:53 A.M. Central Daylight Time,
> sportav8r@gmail.com writes:
>
>
> How about some filtering on the "input" line of the ammeter? If we're
>
> looking at constant-amplitude square wave current pulses of varying frequency,
>
>
> a capacitive filter to perform an "integral" function might give you an
>
> average-current-over-time measurement that closely matches the frequency and
>
> therefore the load on the pump. In practice, I am not sure from listening
>
> to my Facet pump all these years how much the frequency changes as a
>
> function of load. There is a sound change as it self-primes when I first hit
>
> it
>
> before engine-start.
>
>
> Just a thought. I had to do the pneumatic equivalent (expansion chamber
>
> plus input restrictor) to keep my manifold pressure digital readout from
>
> jumping all around in an un-readable fashion. A little RC pi or L network
>
> might do what you need.
>
>
> Bill B.
>
>
> On Mon, Apr 19, 2010 at 9:56 PM, Charlie England <_ceengland@bellsouth.net_
>
> (mailto:ceengland@bellsouth.net) > wrote:
>
>
> <_ceengland@bellsouth.net_ (mailto:ceengland@bellsouth.net) >
>
>
> Certificated. Bummer.
>
>
> If you think you can legally use current sensing, have you tried a
>
> restricter in the pump's output to see if it will raise the current enough to
>
> be
>
> measurable vs the no-flow state?
>
>
> On 4/19/2010 6:16 PM, _BobsV35B@aol.com_ (mailto:BobsV35B@aol.com) wrote:
>
>
> Good Morning Charlie,
>
> Those units by Pillar Point Electronics look very promising. As I said a
>
> couple of messages back, I need something that can be used on a normally
>
> certificated aircraft. Not sure about the PPE product, but I am checking into
>
>
> it.
>
> Thanks for the comment.
>
> Happy Skies,
>
> Old Bob
>
> In a message dated 4/19/2010 4:50:49 P.M. Central Daylight Time,
>
> _ceengland@bellsouth.net_ (mailto:ceengland@bellsouth.net) writes:
>
>
> <_ceengland@bellsouth.net_ (mailto:ceengland@bellsouth.net) >
>
>
> On 4/19/2010 3:03 PM, ROGER & JEAN CURTIS wrote:
>
> >
>
> > To me, they look and sound just like the ones that were used
>
> > on those Ford gasoline fired heaters back in the thirties. But
>
> my memory
>
> > could be fooling me.
>
> >
>
> > Those were probably the Stewart Warner or Bendix pumps.
>
> > Whadda Ya Think?
>
> >
>
> > If so. does that mean I need to monitor the frequency some
>
> > how?
>
> >
>
> > This is getting complicated,. No wonder nobody does it!
>
> >
>
> > Happy Skies,
>
> >
>
> > Old Bob
>
> >
>
> > I am not sure of the application here, but I
>
> > believe that there should be a significant pressure drop on the
>
> output of
>
> > the pump, when there is no longer any fuel. This being the
>
> case, perhaps
>
> > you could use a pressure switch, similar to what is used to
>
> monitor engine
>
> > oil pressure and turn on the hobbs meter, on some aircraft. You
>
> would need
>
> > to check the pressure differential between pumping fuel and
>
> empty tank
>
> > pumping, and use a switch midway between. This would be a
>
> normally closed
>
> > switch which would open when there is fuel flow and close, to
>
> turn on the
>
> > light when there is no more fuel to pump.
>
> >
>
> > Not sure if this is a viable option for your
>
> > application, but might work, and is very simple. (I especially like
>
> > simple:-)
>
> >
>
> > Roger
>
> >
>
> If you're using it as a transfer pump, there won't be a lot of
>
> pressure
>
> since it will be just the 'head' from one tank to the other. Often no
>
> more than a few inches of rise, plus the resistance of the tubing.
>
>
> How about one of the sensing devices using light to detect the
>
> presence
>
> of liquid? I bought a couple several years ago, intending to use
>
> them to
>
> monitor end-of-transfer from my aux tanks, then forgot to install
>
> them.... They mount in a single hole & have a cone shaped plexi
>
> tip. An
>
> LED shines out through the plexi; presence/absence of liquid
>
> changes the
>
> light reflected back into the photocell in the same housing, changing
>
> the state of the sense line.
>
>
> If that interests you, I'll try to locate the name of the device & a
>
> source for you.
>
>
> Charlie
>
>
> ________________________________ Message 4 _____________________________________
>
>
> Time: 06:09:04 AM PST US
>
> Subject: RE: AeroElectric-List: Re: Facet pumps: Energy vs. Flow
>
> From: "Jon Finley" <jon@finleyweb.net>
>
>
> =0AI find this discussion very interesting and hope for an inexpensive solu
>
> tion. I really like that Pillar Point flow detector but the price is more
>
> than I'd like to spend.=0A =0AJust to add some data points.... In my case,
>
> I know the fuel level in the tank but I wish to know when fuel stops being
>
> delivered to that tank so alternate plans can be made. So, a "fuel is not f
>
> lowing" indicator would add a level of comfort (would be "nice" but certain
>
> ly not mandatory since I am currently flying without this).=0A =0AMore spec
>
> ifically, I have a large main tank from which fuel is pumped into the heade
>
> r. The header is about 5 gallons (one hour of flight time). I typically l
>
> eave my transfer pump on all the time. If it were to stop and I didn't not
>
> ice (which is likely), I have a warning light that will come on at about 2.
>
> 5-3 gallons. That leaves me with about 30 minutes to figure out what to do
>
> . If I had known immediately, I would have had 60 minutes. Of course, I h
>
> ave a backup fuel pump which I would immediately switch on. However; it ca
>
> n take some time before seeing the fuel level start to rise. When dealing w
>
> ith a 30 minute window, knowing now versus knowing in 5-10 minutes is a big
>
> deal (at least in terms of my stress level - FYI, I live out west were air
>
> ports are frequently more than 30 minutes apart).=0A=0AJon Finley=0AN314JF
>
> - Q2 - Subaru EJ22=0A[http://www.finleyweb.net/Q2Subaru.aspx] http://www.fi
> nleyweb.net/Q2Subaru.aspx=0A =0A =0A=0A-----Original Message-----=0AFrom: "
>
> rampil" <ira.rampil@gmail.com>=0ASent: Tuesday, April 20, 2010 6:41am=0ATo:
>
> aeroelectric-list@matronics.com=0ASubject: AeroElectric-List: Re: Facet pu
>
> <ira.rampil@gmail.com>=0A=0AGood engineering principles favor measuring th
>
> e actual parameter=0Ayou want, rather than a surrogate, especially when the
>
> re is no=0Areliable one-to-one mapping of one to the other.=0A=0AIn the cas
>
> e of current draw, for example, overheating the coil or dirt=0Ain the mecha
>
> nism will probably change the current draw=0APressure downstream would depe
>
> nd on where the fill hose enters the =0Adownstream tank, if at the bottom,
>
> or at a positive hydrostatic head, the =0Apressure downstream of the pump w
>
> ill stay positive while there is fuel=0Ain the tank.=0A=0AWhat about measur
>
> ing fuel level in the feeding tank, is not that what you=0Areally want to m
>
> ake a decision with? When it reads zero, stop pumping?=0A=0A--------=0AIra
>
> N224XS=0A=0A=0A=0A=0ARead this topic online here:=0A=0Ahttp://forums.matron
>
> ================0A=0A=0A=0A
>
>
> ________________________________ Message 5 _____________________________________
>
>
> Time: 07:51:11 AM PST US
>
> From: BobsV35B@aol.com
>
> Subject: Re: AeroElectric-List:
>
>
> Test --- Do Not Archive
>
>
> In a message dated
>
>
> ________________________________ Message 6 _____________________________________
>
>
> Time: 07:58:18 AM PST US
>
> From: BobsV35B@aol.com
>
> Subject: Re: AeroElectric-List: Re: Facet pumps: Energy vs. Flow
>
>
> Good Morning Ira,
>
>
> I have what I consider to be relatively good fuel gauges in the tanks, but
>
> find that there is at least a ten to fifteen minute window between where
>
> the gauge says empty and it actually will be dry. I do not wish to turn the
>
> pump off too soon and have fuel in the tank that has not been used and I do
>
> not like to run the pump when it is not actually pumping fuel.
>
>
> It would be very nice to be able to verify the accuracy of the fuel gauge
>
> by noting when the pump stops pumping fuel rather than running the pump
>
> while dry for possibly an extra ten to fifteen minutes every time I utilize
the
>
>
> auxiliary fuel tank.
>
>
> I do have excellent fuel use measuring capability and what I do now is note
>
> the fuel burned number when I turn on the pump and shut it off when the
>
> amount of fuel known to be in the tank has been burned.
>
>
> Nevertheless, it would be nice to know within seconds when the tank has run
>
> dry so that the pump could be turned off.
>
>
> I really would rather not be running the pump when it is not pumping fuel.
>
>
> Happy Skies,
>
>
> Old Bob
>
>
> In a message dated 4/20/2010 7:43:50 A.M. Central Daylight Time,
> ira.rampil@gmail.com writes:
>
>
> --> AeroElectric-List message posted by: "rampil" <ira.rampil@gmail.com>
>
>
> Good engineering principles favor measuring the actual parameter
>
> you want, rather than a surrogate, especially when there is no
>
> reliable one-to-one mapping of one to the other.
>
>
> In the case of current draw, for example, overheating the coil or dirt
>
> in the mechanism will probably change the current draw
>
> Pressure downstream would depend on where the fill hose enters the
>
> downstream tank, if at the bottom, or at a positive hydrostatic head, the
>
> pressure downstream of the pump will stay positive while there is fuel
>
> in the tank.
>
>
> What about measuring fuel level in the feeding tank, is not that what you
>
> really want to make a decision with? When it reads zero, stop pumping?
>
>
> --------
>
> Ira N224XS
>
>
> ________________________________ Message 7 _____________________________________
>
>
> Time: 10:35:34 AM PST US
>
> From: Mike Welch <mdnanwelch7@hotmail.com>
>
> Subject: AeroElectric-List: Re: Facet pumps: Energy vs. Flow
>
>
> Bob=2C
>
>
> Pardon me for butting in=2C but from my experience with certificated airp
>
> lanes=2C it is virtually impossible to get a field approval like you're aft
>
> er.
>
>
> I used to have a 1961 Cessna 172=2C with an O-300 Continental. On those
>
> hot mid-summer California days (100+)=2C my oil temps got well into the red
>
> on climbout!! I checked the accuracy of the gauge=2C and it was correct!
>
>
> Therefore=2C I wanted to add an oil cooler to my Cessna 172. It didn't c
>
> ome with one=2C but I could get a later model 172 oil cooler to fit. I sen
>
> t off my Form 337 to the local FSDO=2C and their first reaction was "NO!"
>
> Their attitude was "if it didn't come with one=2C it doesn't need one!!"
>
>
> I was irritated (to say the least)=2C and requested an appeal. They fina
>
> lly relented and said it would be okay. For crying out loud =2C it was jus
>
> t an oil cooler!! (all certified parts=2C too)
>
>
> My opinion is=3B there ain't no way you can legally add any kind of perma
>
> nent parts to modify to your fuel pump=2C fuel lines=2C or anything else=2C
>
> on a certificated airplane=2C without that approved 337.
>
>
> Just my opinion.................
>
>
> Mike Welch
>
>
> From: BobsV35B@aol.com
>
> Subject: Re: AeroElectric-List: Re: Facet pumps: Energy vs. Flow
>
>
> Good Morning Ira=2C
>
>
> I have what I consider to be relatively good fuel gauges in the tanks=2C bu
>
> t find that there is at least a ten to fifteen minute window between where
>
> the gauge says empty and it actually will be dry. I do not wish to turn the
>
> pump off too soon and have fuel in the tank that has not been used and I d
>
> o not like to run the pump when it is not actually pumping fuel.
>
>
> It would be very nice to be able to verify the accuracy of the fuel gauge b
>
> y noting when the pump stops pumping fuel rather than running the pump whil
>
> e dry for possibly an extra ten to fifteen minutes every time I utilize the
>
> auxiliary fuel tank.
>
>
> I do have excellent fuel use measuring capability and what I do now is note
>
> the fuel burned number when I turn on the pump and shut it off when the am
>
> ount of fuel known to be in the tank has been burned.
>
>
> Nevertheless=2C it would be nice to know within seconds when the tank has r
>
> un dry so that the pump could be turned off.
>
>
> I really would rather not be running the pump when it is not pumping fuel.
>
>
> Happy Skies=2C
>
>
> Old Bob
>
>
> In a message dated 4/20/2010 7:43:50 A.M. Central Daylight Time=2C ira.ramp
> il@gmail.com writes:
>
>
> Good engineering principles favor measuring the actual parameter
>
> you want=2C rather than a surrogate=2C especially when there is no
>
> reliable one-to-one mapping of one to the other.
>
>
> In the case of current draw=2C for example=2C overheating the coil or dirt
>
> in the mechanism will probably change the current draw
>
> Pressure downstream would depend on where the fill hose enters the
>
> downstream tank=2C if at the bottom=2C or at a positive hydrostatic head=2C
>
> the
>
> pressure downstream of the pump will stay positive while there is fuel
>
> in the tank.
>
>
> What about measuring fuel level in the feeding tank=2C is not that what you
>
> really want to make a decision with? When it reads zero=2C stop pumping?
>
>
> --------
>
> Ira N224XS
>
>
> _________________________________________________________________
>
> Hotmail is redefining busy with tools for the New Busy. Get more from your
>
> inbox.
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>
> N:WL:en-US:WM_HMP:042010_2
>
>
> ________________________________ Message 8 _____________________________________
>
>
> Time: 11:05:32 AM PST US
>
> From: BobsV35B@aol.com
>
> Subject: Re: AeroElectric-List: Re: Facet pumps: Energy vs. Flow
>
>
> Good Afternoon Mike,
>
>
> Believe it or not I do understand your frustration and the problems that
>
> are faced when dealing with the FAA.
>
> It is my opinion that the vast majority of the folks at FAA want to do a
>
> good job, but are so hamstrung with regulations and paper work that it is
>
> easier to just say no.
>
>
> However, I have had fairly good luck getting local approvals from my
>
> supervising FSDO.
>
>
> As I think we can all agree, each FSDO is a kingdom unto itself and what is
>
> easy to get approved at one office may be impossible at another.
>
> Nevertheless, I have gotten several local approvals here locally. I do hold
an
>
> A&P
>
> with Inspection Authorization. It does help me know who I should present the
>
> data to and how the presentation should be made.
>
>
> In general, if we can think of a way to add something that has no chance of
>
> interfering with required equipment, the local approval has a better
>
> chance of being approved.
>
>
> Once again, the FAA has no obligation to ever issue a local approval. In
>
> fact, if an individual inspector does issue the approval, he is doing it on
>
> his own knowledge and is personally responsible for what happens. In many
>
> ways it is surprising that any FAA inspector ever issues a local approval.
>
> He/she has no obligation to do so. It is just a privilege he has been
>
> accorded. Failure to do so does not hurt his career at all, but making a dumb
>
>
> approval could end his career.
>
>
> Happy Skies,
>
>
> Old Bob
>
>
> In a message dated 4/20/2010 12:37:05 P.M. Central Daylight Time,
> mdnanwelch7@hotmail.com writes:
>
>
> 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.................
>
>
> Mike Welch
>
>
> ________________________________ Message 9 _____________________________________
>
>
> Time: 01:53:26 PM PST US
>
> Subject: AeroElectric-List: Re: switch breaker on ALT field
>
> From: "rckol" <rckol@kaehlers.com>
>
>
> Switch breakers will function for this application.
>
>
> I have read conflicting reports about the long term reliability of these. Some
>
> folks end up tearing them out because they don't hold up and others have no
>
> trouble
>
> with them. Sorry, I don't have any brand specific recommendations. I
>
> am not going to use them.
>
>
> Dick
>
>
> --------
>
> rck
>
>
> Read this topic online here:
>
> http://forums.matronics.com/viewtopic.php?p=295024#295024
>
>
> ________________________________ Message 10 ____________________________________
>
>
> Time: 03:38:33 PM PST US
>
> Subject: AeroElectric-List: S704-1 on Hot Side of Firewall?
>
> From: "Noah" <sgninc@cox.net>
>
>
> I requested the spec sheet for the S704-1 relay from B&C, and it is a Tyco T9A
>
> with an operating temp limit of 85C (185F). This seems a bit low for mounting
>
> in the engine compartment on the firewall. where I had been planning to mount
>
> it. I called B&C to ask them if they recommended mounting these in the engine
>
> compartment and the gentleman I spoke with was not sure - he recommended a post
>
> here.
>
>
> Anybody know what the firewall temps can climb to?? Anybody mounted one of
>
> these
>
> firewall forward in an RV and had problems? Or had it last 2000 hours without
>
> issue??
>
>
> --------
>
> Highest Regards,
>
>
> Noah Forden
>
> RV-7A
>
> Rhode Island
>
>
> Read this topic online here:
>
> http://forums.matronics.com/viewtopic.php?p=295030#295030
>
>
> ________________________________ Message 11 ____________________________________
>
>
> Time: 08:30:35 PM PST US
>
> From: "Robert L. Nuckolls, III" <nuckolls.bob@aeroelectric.com>
>
> Subject: Re: AeroElectric-List: S704-1 on Hot Side of Firewall?
>
>
> At 05:36 PM 4/20/2010, you wrote:
>
> >
>
> >I requested the spec sheet for the S704-1 relay from B&C, and it is
>
> >a Tyco T9A with an operating temp limit of 85C (185F). This seems a
>
> >bit low for mounting in the engine compartment on the firewall.
>
> >where I had been planning to mount it. I called B&C to ask them if
>
> >they recommended mounting these in the engine compartment and the
>
> >gentleman I spoke with was not sure - he recommended a post here.
>
> >
>
> >Anybody know what the firewall temps can climb to?? Anybody mounted
>
> >one of these firewall forward in an RV and had problems? Or had it
>
> >last 2000 hours without issue??
>
>
> It will be fine. These devices and their close
>
> cousins are used under the hood of motor vehicles
>
> and they're fine.
>
>
> The various companies I've worked for have done
>
> numerous studies of temperature under the cowl
>
> and found that nothing gets really all that hot
>
> as long as it's not exposed to direct infra-red
>
> radiation from stacks (particularly turbochargers).
>
> I've seen some RG battery cases melted because they
>
> were too close to exhaust pipes.
>
>
> Bob . . .
>
>
> ________________________________ Message 12 ____________________________________
>
>
> Time: 08:36:06 PM PST US
>
> From: "Robert L. Nuckolls, III" <nuckolls.bob@aeroelectric.com>
>
> Subject: Re: AeroElectric-List: Re: switch breaker on ALT field
>
>
> At 03:50 PM 4/20/2010, you wrote:
>
> >
>
> >Switch breakers will function for this application.
>
> >
>
> >I have read conflicting reports about the long term reliability of
>
> >these. Some folks end up tearing them out because they don't hold
>
> >up and others have no trouble with them. Sorry, I don't have any
>
> >brand specific recommendations. I am not going to use them.
>
>
> The mil-qualified sw/breakers are fine. Actually, the
>
> P&B W31 series are reasonably decent too. There's about
>
> 80K in service in Bonanzas and Barons since way back
>
> when . . . and yes, a few have failed in a way that
>
> put smoke in the cockpit . . . but those were the 30A
>
> devices that control electric prop de-ice.
>
>
> Obviously, you can't get the features in single
>
> switches of any kind that are offered in the progressive-
>
> transfer 2-pole toggles (2-10, 2-50, 2-70) but if your
>
> design goals don't require this feature, then the
>
> single switches will do.
>
>
> Now, having said that, I'm not sure I'd recommend
>
> the W31 used upstream of a crowbar ov protection system
>
> that I designed. I've not studied the trip dynamics of
>
> this device in that application. The miniature TI/Klixon
>
> style breakers have been paired with our crowbar ov
>
> systems by the thousands with good service histories.
>
>
> Bob . . .
>
>
> ===================================
>
> com/Navigator?AeroElectric-List" target="_blank">http://www.matronics.com/Navigator?AeroElectric-List
>
> ===================================
> cs.com" target="_blank">http://forums.matronics.com
>
> ===================================
>
> com/contribution" target="_blank">http://www.matronics.com/contribution
>
> ===================================
>
>
> *
>
> *
>
>
Message 12
INDEX | Back to Main INDEX |
PREVIOUS | Skip to PREVIOUS Message |
NEXT | Skip to NEXT Message |
LIST | Reply to LIST Regarding this Message |
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|
Subject: | Re: High fuel pressure |
Jerry,
I had a similar problem with an occasional high reading. A new ground
wire to the sender took care of the problem.
Sheldon Olesen
On Apr 21, 2010, at 10:46 AM, jerry2dt@aol.com 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.
>
> Thanks all,
>
> Jerry Cochran
>
>
> -----Original Message-----
> From: AeroElectric-List Digest Server
<aeroelectric-list@matronics.com>
> To: AeroElectric-List Digest List
<aeroelectric-list-digest@matronics.com>
> Sent: Tue, Apr 20, 2010 11:55 pm
> Subject: AeroElectric-List Digest: 12 Msgs - 04/20/10
>
> *
>
>
>
> ========================
>
> Online Versions of Today's List Digest Archive
>
> ========================
>
>
>
> Today's complete AeroElectric-List Digest can also be found in either
of the
>
> two Web Links listed below. The .html file includes the Digest
formatted
>
> in HTML for viewing with a web browser and features Hyperlinked
Indexes
>
> and Message Navigation. The .txt file includes the plain ASCII
version
>
> of the AeroElectric-List Digest and can be viewed with a generic text
editor
>
> such as Notepad or with a web browser.
>
>
>
> HTML Version:
>
>
>
>
http://www.matronics.com/digest/digestview.php?Style=82701&View=html&C
hapter 10-04-20&Archive=AeroElectric
>
>
>
> Text Version:
>
>
>
>
http://www.matronics.com/digest/digestview.php?Style=82701&View=txt&Ch
apter 10-04-20&Archive=AeroElectric
>
>
>
>
>
> ========================
=======================
>
> EMail Version of Today's List Digest Archive
>
> ========================
=======================
>
>
>
>
>
> ----------------------------------------------------------
>
> AeroElectric-List Digest Archive
>
> ---
>
> Total Messages Posted Tue 04/20/10: 12
>
> ----------------------------------------------------------
>
>
>
>
>
> Today's Message Index:
>
> ----------------------
>
>
>
> 1. 04:40 AM - Re: Facet pumps: Energy vs. Flow (Bill Boyd)
>
> 2. 05:43 AM - Re: Facet pumps: Energy vs. Flow (rampil)
>
> 3. 05:48 AM - Re: Facet pumps: Energy vs. Flow
(BobsV35B@aol.com)
>
> 4. 06:09 AM - Re: Re: Facet pumps: Energy vs. Flow (Jon Finley)
>
> 5. 07:51 AM - Re: (BobsV35B@aol.com)
>
> 6. 07:58 AM - Re: Re: Facet pumps: Energy vs. Flow
(BobsV35B@aol.com)
>
> 7. 10:35 AM - Re: Facet pumps: Energy vs. Flow (Mike Welch)
>
> 8. 11:05 AM - Re: Re: Facet pumps: Energy vs. Flow
(BobsV35B@aol.com)
>
> 9. 01:53 PM - Re: switch breaker on ALT field (rckol)
>
> 10. 03:38 PM - S704-1 on Hot Side of Firewall? (Noah)
>
> 11. 08:30 PM - Re: S704-1 on Hot Side of Firewall? (Robert L.
Nuckolls,
>
> III)
>
> 12. 08:36 PM - Re: Re: switch breaker on ALT field (Robert L.
Nuckolls,
>
> III)
>
>
>
>
>
>
>
> ________________________________ Message 1
_____________________________________
>
>
>
>
>
> Time: 04:40:20 AM PST US
>
> Subject: Re: AeroElectric-List: Facet pumps: Energy vs. Flow
>
> From: Bill Boyd <sportav8r@gmail.com>
>
>
>
> How about some filtering on the "input" line of the ammeter? If we're
>
> looking at constant-amplitude square wave current pulses of varying
>
> frequency, a capacitive filter to perform an "integral" function might
give
>
> you an average-current-over-time measurement that closely matches the
>
> frequency and therefore the load on the pump. In practice, I am not
sure
>
> from listening to my Facet pump all these years how much the frequency
>
> changes as a function of load. There is a sound change as it
self-primes
>
> when I first hit it before engine-start.
>
>
>
> Just a thought. I had to do the pneumatic equivalent (expansion
chamber
>
> plus input restrictor) to keep my manifold pressure digital readout
from
>
> jumping all around in an un-readable fashion. A little RC pi or L
network
>
> might do what you need.
>
>
>
> Bill B.
>
>
>
> On Mon, Apr 19, 2010 at 9:56 PM, Charlie England
<ceengland@bellsouth.net>wrote:
>
>
>
> > ceengland@bellsouth.net>
>
> >
>
> > Certificated. Bummer.
>
> >
>
> > If you think you can legally use current sensing, have you tried a
>
> > restricter in the pump's output to see if it will raise the current
enough
>
> > to be measurable vs the no-flow state?
>
> >
>
> > On 4/19/2010 6:16 PM, BobsV35B@aol.com wrote:
>
> >
>
> >> Good Morning Charlie,
>
> >> Those units by Pillar Point Electronics look very promising. As I
said a
>
> >> couple of messages back, I need something that can be used on a
normally
>
> >> certificated aircraft. Not sure about the PPE product, but I am
checking
>
> >> into it.
>
> >> Thanks for the comment.
>
> >> Happy Skies,
>
> >> Old Bob
>
> >> In a message dated 4/19/2010 4:50:49 P.M. Central Daylight Time,
>
> >> ceengland@bellsouth.net writes:
>
> >>
>
> >> <ceengland@bellsouth.net>
>
> >>
>
> >> On 4/19/2010 3:03 PM, ROGER & JEAN CURTIS wrote:
>
> >> >
>
> >> > To me, they look and sound just like the ones that were
used
>
> >> > on those Ford gasoline fired heaters back in the thirties. But
>
> >> my memory
>
> >> > could be fooling me.
>
> >> >
>
> >> > Those were probably the Stewart Warner or Bendix pumps.
>
> >> > Whadda Ya Think?
>
> >> >
>
> >> > If so. does that mean I need to monitor the frequency
some
>
> >> > how?
>
> >> >
>
> >> > This is getting complicated,. No wonder nobody does it!
>
> >> >
>
> >> > Happy Skies,
>
> >> >
>
> >> > Old Bob
>
> >> >
>
> >> > I am not sure of the application here, but I
>
> >> > believe that there should be a significant pressure drop on
the
>
> >> output of
>
> >> > the pump, when there is no longer any fuel. This being the
>
> >> case, perhaps
>
> >> > you could use a pressure switch, similar to what is used to
>
> >> monitor engine
>
> >> > oil pressure and turn on the hobbs meter, on some aircraft.
You
>
> >> would need
>
> >> > to check the pressure differential between pumping fuel and
>
> >> empty tank
>
> >> > pumping, and use a switch midway between. This would be a
>
> >> normally closed
>
> >> > switch which would open when there is fuel flow and close, to
>
> >> turn on the
>
> >> > light when there is no more fuel to pump.
>
> >> >
>
> >> > Not sure if this is a viable option for your
>
> >> > application, but might work, and is very simple. (I
especially like
>
> >> > simple:-)
>
> >> >
>
> >> > Roger
>
> >> >
>
> >> If you're using it as a transfer pump, there won't be a lot of
>
> >> pressure
>
> >> since it will be just the 'head' from one tank to the other.
Often no
>
> >> more than a few inches of rise, plus the resistance of the
tubing.
>
> >>
>
> >> How about one of the sensing devices using light to detect the
>
> >> presence
>
> >> of liquid? I bought a couple several years ago, intending to use
>
> >> them to
>
> >> monitor end-of-transfer from my aux tanks, then forgot to
install
>
> >> them.... They mount in a single hole & have a cone shaped plexi
>
> >> tip. An
>
> >> LED shines out through the plexi; presence/absence of liquid
>
> >> changes the
>
> >> light reflected back into the photocell in the same housing,
changing
>
> >> the state of the sense line.
>
> >>
>
> >> If that interests you, I'll try to locate the name of the device
& a
>
> >> source for you.
>
> >>
>
> >> Charlie
>
> >>
>
> >> *
>
> >>
>
> >>
>
> >> *
>
> >>
>
> >
>
> >
>
>
>
> ________________________________ Message 2
_____________________________________
>
>
>
>
>
> Time: 05:43:01 AM PST US
>
> Subject: AeroElectric-List: Re: Facet pumps: Energy vs. Flow
>
> From: "rampil" <ira.rampil@gmail.com>
>
>
>
>
>
> Good engineering principles favor measuring the actual parameter
>
> you want, rather than a surrogate, especially when there is no
>
> reliable one-to-one mapping of one to the other.
>
>
>
> In the case of current draw, for example, overheating the coil or dirt
>
> in the mechanism will probably change the current draw
>
> Pressure downstream would depend on where the fill hose enters the
>
> downstream tank, if at the bottom, or at a positive hydrostatic head,
the
>
> pressure downstream of the pump will stay positive while there is fuel
>
> in the tank.
>
>
>
> What about measuring fuel level in the feeding tank, is not that what
you
>
> really want to make a decision with? When it reads zero, stop pumping?
>
>
>
> --------
>
> Ira N224XS
>
>
>
>
>
> Read this topic online here:
>
>
>
> http://forums.matronics.com/viewtopic.php?p=294942#294942
>
>
>
>
>
> ________________________________ Message 3
_____________________________________
>
>
>
>
>
> Time: 05:48:55 AM PST US
>
> From: BobsV35B@aol.com
>
> Subject: Re: AeroElectric-List: Facet pumps: Energy vs. Flow
>
>
>
> Good Morning Bill,
>
>
>
> Wow!
>
>
>
> It appears that any suitable current measuring device will be a lot
more
>
> complex than my feeble brain can comprehend.
>
>
>
> Thanks to you and all the others that have contributed to my on going
>
> education.
>
>
>
> In any case, it does seem that a few breadboard experiments are in
order.
>
>
>
> Happy Skies,
>
>
>
> Old Bob
>
>
>
>
>
> In a message dated 4/20/2010 6:41:53 A.M. Central Daylight Time,
>
> sportav8r@gmail.com writes:
>
>
>
> How about some filtering on the "input" line of the ammeter? If
we're
>
> looking at constant-amplitude square wave current pulses of varying
frequency,
>
>
>
> a capacitive filter to perform an "integral" function might give you
an
>
> average-current-over-time measurement that closely matches the
frequency and
>
> therefore the load on the pump. In practice, I am not sure from
listening
>
> to my Facet pump all these years how much the frequency changes as a
>
> function of load. There is a sound change as it self-primes when I
first hit
>
> it
>
> before engine-start.
>
>
>
>
>
> Just a thought. I had to do the pneumatic equivalent (expansion
chamber
>
> plus input restrictor) to keep my manifold pressure digital readout
from
>
> jumping all around in an un-readable fashion. A little RC pi or L
network
>
> might do what you need.
>
>
>
>
>
> Bill B.
>
>
>
> On Mon, Apr 19, 2010 at 9:56 PM, Charlie England
<_ceengland@bellsouth.net_
>
> (mailto:ceengland@bellsouth.net) > wrote:
>
>
>
> <_ceengland@bellsouth.net_ (mailto:ceengland@bellsouth.net) >
>
>
>
> Certificated. Bummer.
>
>
>
> If you think you can legally use current sensing, have you tried a
>
> restricter in the pump's output to see if it will raise the current
enough to
>
> be
>
> measurable vs the no-flow state?
>
>
>
> On 4/19/2010 6:16 PM, _BobsV35B@aol.com_ (mailto:BobsV35B@aol.com)
wrote:
>
>
>
> Good Morning Charlie,
>
> Those units by Pillar Point Electronics look very promising. As I
said a
>
> couple of messages back, I need something that can be used on a
normally
>
> certificated aircraft. Not sure about the PPE product, but I am
checking into
>
>
>
> it.
>
> Thanks for the comment.
>
> Happy Skies,
>
> Old Bob
>
> In a message dated 4/19/2010 4:50:49 P.M. Central Daylight Time,
>
> _ceengland@bellsouth.net_ (mailto:ceengland@bellsouth.net) writes:
>
>
>
> <_ceengland@bellsouth.net_ (mailto:ceengland@bellsouth.net) >
>
>
>
> On 4/19/2010 3:03 PM, ROGER & JEAN CURTIS wrote:
>
> >
>
> > To me, they look and sound just like the ones that were used
>
> > on those Ford gasoline fired heaters back in the thirties. But
>
> my memory
>
> > could be fooling me.
>
> >
>
> > Those were probably the Stewart Warner or Bendix pumps.
>
> > Whadda Ya Think?
>
> >
>
> > If so. does that mean I need to monitor the frequency some
>
> > how?
>
> >
>
> > This is getting complicated,. No wonder nobody does it!
>
> >
>
> > Happy Skies,
>
> >
>
> > Old Bob
>
> >
>
> > I am not sure of the application here, but I
>
> > believe that there should be a significant pressure drop on the
>
> output of
>
> > the pump, when there is no longer any fuel. This being the
>
> case, perhaps
>
> > you could use a pressure switch, similar to what is used to
>
> monitor engine
>
> > oil pressure and turn on the hobbs meter, on some aircraft. You
>
> would need
>
> > to check the pressure differential between pumping fuel and
>
> empty tank
>
> > pumping, and use a switch midway between. This would be a
>
> normally closed
>
> > switch which would open when there is fuel flow and close, to
>
> turn on the
>
> > light when there is no more fuel to pump.
>
> >
>
> > Not sure if this is a viable option for your
>
> > application, but might work, and is very simple. (I especially like
>
> > simple:-)
>
> >
>
> > Roger
>
> >
>
> If you're using it as a transfer pump, there won't be a lot of
>
> pressure
>
> since it will be just the 'head' from one tank to the other. Often no
>
> more than a few inches of rise, plus the resistance of the tubing.
>
>
>
> How about one of the sensing devices using light to detect the
>
> presence
>
> of liquid? I bought a couple several years ago, intending to use
>
> them to
>
> monitor end-of-transfer from my aux tanks, then forgot to install
>
> them.... They mount in a single hole & have a cone shaped plexi
>
> tip. An
>
> LED shines out through the plexi; presence/absence of liquid
>
> changes the
>
> light reflected back into the photocell in the same housing, changing
>
> the state of the sense line.
>
>
>
> If that interests you, I'll try to locate the name of the device & a
>
> source for you.
>
>
>
> Charlie
>
>
>
>
>
> ________________________________ Message 4
_____________________________________
>
>
>
>
>
> Time: 06:09:04 AM PST US
>
> Subject: RE: AeroElectric-List: Re: Facet pumps: Energy vs. Flow
>
> From: "Jon Finley" <jon@finleyweb.net>
>
>
>
> =0AI find this discussion very interesting and hope for an
inexpensive solu
>
> tion. I really like that Pillar Point flow detector but the price is
more
>
> than I'd like to spend.=0A =0AJust to add some data points.... In
my case,
>
> I know the fuel level in the tank but I wish to know when fuel stops
being
>
> delivered to that tank so alternate plans can be made. So, a "fuel is
not f
>
> lowing" indicator would add a level of comfort (would be "nice" but
certain
>
> ly not mandatory since I am currently flying without this).=0A
=0AMore spec
>
> ifically, I have a large main tank from which fuel is pumped into the
heade
>
> r. The header is about 5 gallons (one hour of flight time). I
typically l
>
> eave my transfer pump on all the time. If it were to stop and I
didn't not
>
> ice (which is likely), I have a warning light that will come on at
about 2.
>
> 5-3 gallons. That leaves me with about 30 minutes to figure out what
to do
>
> . If I had known immediately, I would have had 60 minutes. Of
course, I h
>
> ave a backup fuel pump which I would immediately switch on. However;
it ca
>
> n take some time before seeing the fuel level start to rise. When
dealing w
>
> ith a 30 minute window, knowing now versus knowing in 5-10 minutes is
a big
>
> deal (at least in terms of my stress level - FYI, I live out west
were air
>
> ports are frequently more than 30 minutes apart).=0A=0AJon
Finley=0AN314JF
>
> - Q2 - Subaru EJ22=0A[http://www.finleyweb.net/Q2Subaru.aspx]
http://www.fi
>
> nleyweb.net/Q2Subaru.aspx=0A =0A =0A=0A-----Original
Message-----=0AFrom: "
>
> rampil" <ira.rampil@gmail.com>=0ASent: Tuesday, April 20, 2010
6:41am=0ATo:
>
> aeroelectric-list@matronics.com=0ASubject: AeroElectric-List: Re:
Facet pu
>
> <ira.rampil@gmail.com>=0A=0AGood engineering principles favor
measuring th
>
> e actual parameter=0Ayou want, rather than a surrogate, especially
when the
>
> re is no=0Areliable one-to-one mapping of one to the other.=0A=0AI
n the cas
>
> e of current draw, for example, overheating the coil or dirt=0Ain
the mecha
>
> nism will probably change the current draw=0APressure downstream
would depe
>
> nd on where the fill hose enters the =0Adownstream tank, if at the
bottom,
>
> or at a positive hydrostatic head, the =0Apressure downstream of the
pump w
>
> ill stay positive while there is fuel=0Ain the tank.=0A=0AWhat
about measur
>
> ing fuel level in the feeding tank, is not that what you=0Areally
want to m
>
> ake a decision with? When it reads zero, stop
pumping?=0A=0A--------=0AIra
>
> N224XS=0A=0A=0A=0A=0ARead this topic online
here:=0A=0Ahttp://forums.matron
>
> ================0A=0A=0A=0A
>
>
>
> ________________________________ Message 5
_____________________________________
>
>
>
>
>
> Time: 07:51:11 AM PST US
>
> From: BobsV35B@aol.com
>
> Subject: Re: AeroElectric-List:
>
>
>
> Test --- Do Not Archive
>
>
>
>
>
> In a message dated
>
>
>
> ________________________________ Message 6
_____________________________________
>
>
>
>
>
> Time: 07:58:18 AM PST US
>
> From: BobsV35B@aol.com
>
> Subject: Re: AeroElectric-List: Re: Facet pumps: Energy vs. Flow
>
>
>
> Good Morning Ira,
>
>
>
> I have what I consider to be relatively good fuel gauges in the tanks,
but
>
> find that there is at least a ten to fifteen minute window between
where
>
> the gauge says empty and it actually will be dry. I do not wish to
turn the
>
> pump off too soon and have fuel in the tank that has not been used
and I do
>
> not like to run the pump when it is not actually pumping fuel.
>
>
>
> It would be very nice to be able to verify the accuracy of the fuel
gauge
>
> by noting when the pump stops pumping fuel rather than running the
pump
>
> while dry for possibly an extra ten to fifteen minutes every time I
utilize the
>
>
>
> auxiliary fuel tank.
>
>
>
> I do have excellent fuel use measuring capability and what I do now is
note
>
> the fuel burned number when I turn on the pump and shut it off when
the
>
> amount of fuel known to be in the tank has been burned.
>
>
>
> Nevertheless, it would be nice to know within seconds when the tank
has run
>
> dry so that the pump could be turned off.
>
>
>
> I really would rather not be running the pump when it is not pumping
fuel.
>
>
>
> Happy Skies,
>
>
>
> Old Bob
>
>
>
>
>
> In a message dated 4/20/2010 7:43:50 A.M. Central Daylight Time,
>
> ira.rampil@gmail.com writes:
>
>
>
> --> AeroElectric-List message posted by: "rampil"
<ira.rampil@gmail.com>
>
>
>
> Good engineering principles favor measuring the actual parameter
>
> you want, rather than a surrogate, especially when there is no
>
> reliable one-to-one mapping of one to the other.
>
>
>
> In the case of current draw, for example, overheating the coil or
dirt
>
> in the mechanism will probably change the current draw
>
> Pressure downstream would depend on where the fill hose enters the
>
> downstream tank, if at the bottom, or at a positive hydrostatic head,
the
>
> pressure downstream of the pump will stay positive while there is
fuel
>
> in the tank.
>
>
>
> What about measuring fuel level in the feeding tank, is not that what
you
>
> really want to make a decision with? When it reads zero, stop
pumping?
>
>
>
> --------
>
> Ira N224XS
>
>
>
>
>
> ________________________________ Message 7
_____________________________________
>
>
>
>
>
> Time: 10:35:34 AM PST US
>
> From: Mike Welch <mdnanwelch7@hotmail.com>
>
> Subject: AeroElectric-List: Re: Facet pumps: Energy vs. Flow
>
>
>
>
>
> Bob=2C
>
>
>
>
>
> Pardon me for butting in=2C but from my experience with
certificated airp
>
> lanes=2C it is virtually impossible to get a field approval like
you're aft
>
> er.
>
>
>
>
>
> I used to have a 1961 Cessna 172=2C with an O-300 Continental. On
those
>
> hot mid-summer California days (100+)=2C my oil temps got well into
the red
>
> on climbout!! I checked the accuracy of the gauge=2C and it was
correct!
>
>
>
>
>
> Therefore=2C I wanted to add an oil cooler to my Cessna 172. It
didn't c
>
> ome with one=2C but I could get a later model 172 oil cooler to fit.
I sen
>
> t off my Form 337 to the local FSDO=2C and their first reaction was
"NO!"
>
> Their attitude was "if it didn't come with one=2C it doesn't need
one!!"
>
>
>
>
>
> I was irritated (to say the least)=2C and requested an appeal.
They fina
>
> lly relented and said it would be okay. For crying out loud =2C it
was jus
>
> t an oil cooler!! (all certified parts=2C too)
>
>
>
>
>
> My opinion is=3B there ain't no way you can legally add any kind
of perma
>
> nent parts to modify to your fuel pump=2C fuel lines=2C or
anything else=2C
>
> on a certificated airplane=2C without that approved 337.
>
>
>
>
>
> Just my opinion.................
>
>
>
>
>
> Mike Welch
>
>
>
>
>
> From: BobsV35B@aol.com
>
> Subject: Re: AeroElectric-List: Re: Facet pumps: Energy vs. Flow
>
>
>
>
>
> Good Morning Ira=2C
>
>
>
> I have what I consider to be relatively good fuel gauges in the
tanks=2C bu
>
> t find that there is at least a ten to fifteen minute window between
where
>
> the gauge says empty and it actually will be dry. I do not wish to
turn the
>
> pump off too soon and have fuel in the tank that has not been used
and I d
>
> o not like to run the pump when it is not actually pumping fuel.
>
>
>
> It would be very nice to be able to verify the accuracy of the fuel
gauge b
>
> y noting when the pump stops pumping fuel rather than running the pump
whil
>
> e dry for possibly an extra ten to fifteen minutes every time I
utilize the
>
> auxiliary fuel tank.
>
>
>
> I do have excellent fuel use measuring capability and what I do now is
note
>
> the fuel burned number when I turn on the pump and shut it off when
the am
>
> ount of fuel known to be in the tank has been burned.
>
>
>
> Nevertheless=2C it would be nice to know within seconds when the
tank has r
>
> un dry so that the pump could be turned off.
>
>
>
> I really would rather not be running the pump when it is not pumping
fuel.
>
>
>
> Happy Skies=2C
>
>
>
> Old Bob
>
>
>
>
>
> In a message dated 4/20/2010 7:43:50 A.M. Central Daylight Time=2C
ira.ramp
>
> il@gmail.com writes:
>
>
>
> Good engineering principles favor measuring the actual parameter
>
> you want=2C rather than a surrogate=2C especially when there is no
>
> reliable one-to-one mapping of one to the other.
>
>
>
> In the case of current draw=2C for example=2C overheating the coil
or dirt
>
> in the mechanism will probably change the current draw
>
> Pressure downstream would depend on where the fill hose enters the
>
> downstream tank=2C if at the bottom=2C or at a positive
hydrostatic head=2C
>
> the
>
> pressure downstream of the pump will stay positive while there is fuel
>
> in the tank.
>
>
>
> What about measuring fuel level in the feeding tank=2C is not that
what you
>
> really want to make a decision with? When it reads zero=2C stop
pumping?
>
>
>
> --------
>
> Ira N224XS
>
>
>
>
>
>
>
> _________________________________________________________________
>
> 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
>
>
>
> ________________________________ Message 8
_____________________________________
>
>
>
>
>
> Time: 11:05:32 AM PST US
>
> From: BobsV35B@aol.com
>
> Subject: Re: AeroElectric-List: Re: Facet pumps: Energy vs. Flow
>
>
>
> Good Afternoon Mike,
>
>
>
> Believe it or not I do understand your frustration and the problems
that
>
> are faced when dealing with the FAA.
>
> It is my opinion that the vast majority of the folks at FAA want to do
a
>
> good job, but are so hamstrung with regulations and paper work that it
is
>
> easier to just say no.
>
>
>
> However, I have had fairly good luck getting local approvals from my
>
> supervising FSDO.
>
>
>
> As I think we can all agree, each FSDO is a kingdom unto itself and
what is
>
> easy to get approved at one office may be impossible at another.
>
> Nevertheless, I have gotten several local approvals here locally. I
do hold an
>
> A&P
>
> with Inspection Authorization. It does help me know who I should
present the
>
> data to and how the presentation should be made.
>
>
>
> In general, if we can think of a way to add something that has no
chance of
>
> interfering with required equipment, the local approval has a better
>
> chance of being approved.
>
>
>
> Once again, the FAA has no obligation to ever issue a local approval.
In
>
> fact, if an individual inspector does issue the approval, he is doing
it on
>
> his own knowledge and is personally responsible for what happens. In
many
>
> ways it is surprising that any FAA inspector ever issues a local
approval.
>
> He/she has no obligation to do so. It is just a privilege he has
been
>
> accorded. Failure to do so does not hurt his career at all, but
making a dumb
>
>
>
> approval could end his career.
>
>
>
> Happy Skies,
>
>
>
> Old Bob
>
>
>
>
>
> In a message dated 4/20/2010 12:37:05 P.M. Central Daylight Time,
>
> mdnanwelch7@hotmail.com writes:
>
>
>
> 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.................
>
>
>
> Mike Welch
>
>
>
>
>
> ________________________________ Message 9
_____________________________________
>
>
>
>
>
> Time: 01:53:26 PM PST US
>
> Subject: AeroElectric-List: Re: switch breaker on ALT field
>
> From: "rckol" <rckol@kaehlers.com>
>
>
>
>
>
> Switch breakers will function for this application.
>
>
>
> I have read conflicting reports about the long term reliability of
these. Some
>
> folks end up tearing them out because they don't hold up and others
have no
>
> trouble
>
> with them. Sorry, I don't have any brand specific recommendations. I
>
> am not going to use them.
>
>
>
> Dick
>
>
>
> --------
>
> rck
>
>
>
>
>
> Read this topic online here:
>
>
>
> http://forums.matronics.com/viewtopic.php?p=295024#295024
>
>
>
>
>
> ________________________________ Message 10
____________________________________
>
>
>
>
>
> Time: 03:38:33 PM PST US
>
> Subject: AeroElectric-List: S704-1 on Hot Side of Firewall?
>
> From: "Noah" <sgninc@cox.net>
>
>
>
>
>
> I requested the spec sheet for the S704-1 relay from B&C, and it is a
Tyco T9A
>
> with an operating temp limit of 85C (185F). This seems a bit low for
mounting
>
> in the engine compartment on the firewall. where I had been planning
to mount
>
> it. I called B&C to ask them if they recommended mounting these in
the engine
>
> compartment and the gentleman I spoke with was not sure - he
recommended a post
>
> here.
>
>
>
> Anybody know what the firewall temps can climb to?? Anybody mounted
one of
>
> these
>
> firewall forward in an RV and had problems? Or had it last 2000 hours
without
>
> issue??
>
>
>
> --------
>
> Highest Regards,
>
>
>
> Noah Forden
>
> RV-7A
>
> Rhode Island
>
>
>
>
>
> Read this topic online here:
>
>
>
> http://forums.matronics.com/viewtopic.php?p=295030#295030
>
>
>
>
>
> ________________________________ Message 11
____________________________________
>
>
>
>
>
> Time: 08:30:35 PM PST US
>
> From: "Robert L. Nuckolls, III" <nuckolls.bob@aeroelectric.com>
>
> Subject: Re: AeroElectric-List: S704-1 on Hot Side of Firewall?
>
>
>
>
>
> At 05:36 PM 4/20/2010, you wrote:
>
> >
>
> >I requested the spec sheet for the S704-1 relay from B&C, and it is
>
> >a Tyco T9A with an operating temp limit of 85C (185F). This seems a
>
> >bit low for mounting in the engine compartment on the firewall.
>
> >where I had been planning to mount it. I called B&C to ask them if
>
> >they recommended mounting these in the engine compartment and the
>
> >gentleman I spoke with was not sure - he recommended a post here.
>
> >
>
> >Anybody know what the firewall temps can climb to?? Anybody mounted
>
> >one of these firewall forward in an RV and had problems? Or had it
>
> >last 2000 hours without issue??
>
>
>
> It will be fine. These devices and their close
>
> cousins are used under the hood of motor vehicles
>
> and they're fine.
>
>
>
> The various companies I've worked for have done
>
> numerous studies of temperature under the cowl
>
> and found that nothing gets really all that hot
>
> as long as it's not exposed to direct infra-red
>
> radiation from stacks (particularly turbochargers).
>
> I've seen some RG battery cases melted because they
>
> were too close to exhaust pipes.
>
>
>
> Bob . . .
>
>
>
>
>
> ________________________________ Message 12
____________________________________
>
>
>
>
>
> Time: 08:36:06 PM PST US
>
> From: "Robert L. Nuckolls, III" <nuckolls.bob@aeroelectric.com>
>
> Subject: Re: AeroElectric-List: Re: switch breaker on ALT field
>
>
>
>
>
> At 03:50 PM 4/20/2010, you wrote:
>
> >
>
> >Switch breakers will function for this application.
>
> >
>
> >I have read conflicting reports about the long term reliability of
>
> >these. Some folks end up tearing them out because they don't hold
>
> >up and others have no trouble with them. Sorry, I don't have any
>
> >brand specific recommendations. I am not going to use them.
>
>
>
> The mil-qualified sw/breakers are fine. Actually, the
>
> P&B W31 series are reasonably decent too. There's about
>
> 80K in service in Bonanzas and Barons since way back
>
> when . . . and yes, a few have failed in a way that
>
> put smoke in the cockpit . . . but those were the 30A
>
> devices that control electric prop de-ice.
>
>
>
> Obviously, you can't get the features in single
>
> switches of any kind that are offered in the progressive-
>
> transfer 2-pole toggles (2-10, 2-50, 2-70) but if your
>
> design goals don't require this feature, then the
>
> single switches will do.
>
>
>
> Now, having said that, I'm not sure I'd recommend
>
> the W31 used upstream of a crowbar ov protection system
>
> that I designed. I've not studied the trip dynamics of
>
> this device in that application. The miniature TI/Klixon
>
> style breakers have been paired with our crowbar ov
>
> systems by the thousands with good service histories.
>
>
>
> Bob . . .
>
>
>
>
>
>
>
>
>
>
>
> ========================
===========
>
> com/Navigator?AeroElectric-List"
target="_blank">http://www.matronics.com/Navigator?AeroElectric-List
>
> ========================
===========
>
> cs.com" target="_blank">http://forums.matronics.com
>
> ========================
===========
>
> com/contribution"
target="_blank">http://www.matronics.com/contribution
>
> ========================
===========
>
>
>
>
>
>
>
>
>
>
>
>
Message 13
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|
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
Message 14
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|
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
Message 15
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|
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
Message 16
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Subject: | Re: Surface temperature sensor |
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
Message 17
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Subject: | Re: Surface temperature sensor |
Do Not Archive
Thanks IRA,
Yes, I'll do some digging. I was thinking about something with a flat
profile and perhaps a stick on for a flat surface. There must be
somebody putting out a device that can be fastened to a flat surface
that has two wires sticking out of it.
Glenn
Do Not Archive
-----Original Message-----
From: owner-aeroelectric-list-server@matronics.com
[mailto:owner-aeroelectric-list-server@matronics.com] On Behalf Of
rampil
Sent: Wednesday, April 21, 2010 4:11 PM
Subject: AeroElectric-List: Re: Surface temperature sensor
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
Message 18
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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@cyberport.net
Tom Kuffel
EAA Flight Advisor
Message 19
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Subject: | Re: Surface temperature sensor |
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
Message 20
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Getting ready to crimp a Radio Shack 1N5400 diode into a fast-on tab for my
SD-8 relay control and thought -- "gee, maybe I better check this diode to
make sure it's good before I do this" -- what could be simpler? -Current
flows from the non-band side of the diode to the band side, but not the ot
her way (just like the schematic), right? -Get out the multi-meter, set i
t to measure ohms. -I put the red lead on the non-band side and the black
lead on the band side and expect to see zero (or very little) resistance.
-Uh oh....infinite resistance...not good...do I have the leads reversed o
n the meter? -Nope. -I reverse the leads (red on band-side and black on
non-band-side...expecting to see infinite resistance) and see...uh oh...3
milliohms. -Now I'm really confused. -I pull another diode out of the p
acket and repeat the test....same result. -I check the heat-sinked bridge
recitifier for the ebus regular feed...same result.
I believe the chance that three different components turned out defective o
r mis-labeled are pretty remote and the chance that my knowledge of all thi
ngs electric is (once again) in need of improvement. -Perhaps I just don'
t understand how the multimeter works.
My question:
For a functioning diode, shouldn't current flow from the red lead of the mu
ltimeter when it's placed on the non-band side of the diode, to the black l
ead 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.
Do Not Archive
Lincoln KeillRV-7A
Message 21
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Subject: | Re: Diode confusion |
Your diodes are fine...you hooked the meter up backwards!
See here for an explanation: http://tinyurl.com/26pwfwg
Harley
------------------------------------------------------------------------
On 4/21/2010 7:41 PM, Lincoln Keill wrote:
> Getting ready to crimp a Radio Shack 1N5400 diode into a fast-on tab
> for my SD-8 relay control and thought -- "gee, maybe I better check
> this diode to make sure it's good before I do this" -- what could be
> simpler? Current flows from the non-band side of the diode to the
> band side, but not the other way (just like the schematic), right?
> Get out the multi-meter, set it to measure ohms. I put the red lead
> on the non-band side and the black lead on the band side and expect to
> see zero (or very little) resistance. Uh oh....infinite
> resistance...not good...do I have the leads reversed on the meter?
> Nope. I reverse the leads (red on band-side and black on
> non-band-side...expecting to see infinite resistance) and see...uh
> oh...3 milliohms. Now I'm really confused. I pull another diode out
> of the packet and repeat the test....same result. I check the
> heat-sinked bridge recitifier for the ebus regular feed...same result.
>
> I believe the chance that three different components turned out
> defective or mis-labeled are pretty remote and the chance that my
> knowledge of all things electric is (once again) in need of
> improvement. Perhaps I just don't understand how the multimeter works.
>
> 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.
>
> Do Not Archive
>
> Lincoln Keill
> RV-7A
>
> *
>
>
> *
>
>
> Checked by AVG - www.avg.com
>
>
Message 22
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Subject: | Re: High fuel pressure |
I bought all my GRT stuff new but second hand and had it shipped to GRT for inspection.
They asked me if I wanted to swap out the fuel sender for the "good"
one. I did this and was told the standard one has a rather short life expectancy.
If you find its the sender you might get the good one this time.
Tim A
________________________________
From: "jerry2dt@aol.com" <jerry2dt@aol.com>
Sent: Wed, April 21, 2010 8:46:44 AM
Subject: AeroElectric-List: High fuel pressure
________________________________
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.
Thanks all,
Jerry Cochran
-----Original Message-----
From: AeroElectric-List Digest Server <aeroelectric-list@matronics.com>
Sent: Tue, Apr 20, 2010 11:55 pm
Subject: AeroElectric-List Digest: 12 Msgs - 04/20/10
*
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Total Messages Posted Tue 04/20/10: 12
----------------------------------------------------------
Today's Message Index:
----------------------
1. 04:40 AM - Re: Facet pumps: Energy vs. Flow (Bill Boyd)
2. 05:43 AM - Re: Facet pumps: Energy vs. Flow (rampil)
3. 05:48 AM - Re: Facet pumps: Energy vs. Flow (BobsV35B@aol.com)
4. 06:09 AM - Re: Re: Facet pumps: Energy vs. Flow (Jon Finley)
5. 07:51 AM - Re: (BobsV35B@aol.com)
6. 07:58 AM - Re: Re: Facet pumps: Energy vs. Flow (BobsV35B@aol.com)
7. 10:35 AM - Re: Facet pumps: Energy vs. Flow (Mike Welch)
8. 11:05 AM - Re: Re: Facet pumps: Energy vs. Flow (BobsV35B@aol.com)
9. 01:53 PM - Re: switch breaker on ALT field (rckol)
10. 03:38 PM - S704-1 on Hot Side of Firewall? (Noah)
11. 08:30 PM - Re: S704-1 on Hot Side of Firewall? (Robert L. Nuckolls,
III)
12. 08:36 PM - Re: Re: switch breaker on ALT field (Robert L. Nuckolls,
III)
________________________________ Message 1 _____________________________________
Time: 04:40:20 AM PST US
Subject: Re: AeroElectric-List: Facet pumps: Energy vs. Flow
From: Bill Boyd <sportav8r@gmail.com>
How about some filtering on the "input" line of the ammeter? If we're
looking at constant-amplitude square wave current pulses of varying
frequency, a capacitive filter to perform an "integral" function might give
you an average-current-over-time measurement that closely matches the
frequency and therefore the load on the pump. In practice, I am not sure
from listening to my Facet pump all these years how much the frequency
changes as a function of load. There is a sound change as it self-primes
when I first hit it before engine-start.
Just a thought. I had to do the pneumatic equivalent (expansion chamber
plus input restrictor) to keep my manifold pressure digital readout from
jumping all around in an un-readable fashion. A little RC pi or L network
might do what you need.
Bill B.
On Mon, Apr 19, 2010 at 9:56 PM, Charlie England <ceengland@bellsouth.net>wrote:
> ceengland@bellsouth.net>
>
> Certificated. Bummer.
>
> If you think you can legally use current sensing, have you tried a
> restricter in the pump's output to see if it will raise the current enough
> to be measurable vs the no-flow state?
>
> On 4/19/2010 6:16 PM, BobsV35B@aol.com wrote:
>
>> Good Morning Charlie,
>> Those units by Pillar Point Electronics look very promising. As I said a
>> couple of messages back, I need something that can be used on a normally
>> certificated aircraft. Not sure about the PPE product, but I am checking
>> into it.
>> Thanks for the comment.
>> Happy Skies,
>> Old Bob
>> In a message dated 4/19/2010 4:50:49 P.M. Central Daylight Time,
>> ceengland@bellsouth.net writes:
>>
>> <ceengland@bellsouth.net>
>>
>> On 4/19/2010 3:03 PM, ROGER & JEAN CURTIS wrote:
>> >
>> > To me, they look and sound just like the ones that were used
>> > on those Ford gasoline fired heaters back in the thirties. But
>> my memory
>> > could be fooling me.
>> >
>> > Those were probably the Stewart Warner or Bendix pumps.
>> > Whadda Ya Think?
>> >
>> > If so. does that mean I need to monitor the frequency some
>> > how?
>> >
>> > This is getting complicated,. No wonder nobody does it!
>> >
>> > Happy Skies,
>> >
>> > Old Bob
>> >
>> > I am not sure of the application here, but I
>> > believe that there should be a significant pressure drop on the
>> output of
>> > the pump, when there is no longer any fuel. This being the
>> case, perhaps
>> > you could use a pressure switch, similar to what is used to
>> monitor engine
>> > oil pressure and turn on the hobbs meter, on some aircraft. You
>> would need
>> > to check the pressure differential between pumping fuel and
>> empty tank
>> > pumping, and use a switch midway between. This would be a
>> normally closed
>> > switch which would open when there is fuel flow and close, to
>> turn on the
>> > light when there is no more fuel to pump.
>> >
>> > Not sure if this is a viable option for your
>> > application, but might work, and is very simple. (I especially like
>> > simple:-)
>> >
>> > Roger
>> >
>> If you're using it as a transfer pump, there won't be a lot of
>> pressure
>> since it will be just the 'head' from one tank to the other. Often no
>> more than a few inches of rise, plus the resistance of the tubing.
>>
>> How about one of the sensing devices using light to detect the
>> presence
>> of liquid? I bought a couple several years ago, intending to use
>> them to
>> monitor end-of-transfer from my aux tanks, then forgot to install
>> them.... They mount in a single hole & have a cone shaped plexi
>> tip. An
>> LED shines out through the plexi; presence/absence of liquid
>> changes the
>> light reflected back into the photocell in the same housing, changing
>> the state of the sense line.
>>
>> If that interests you, I'll try to locate the name of the device & a
>> source for you.
>>
>> Charlie
>>
>> *
>>
>>
>> *
>>
>
>
________________________________ Message 2 _____________________________________
Time: 05:43:01 AM PST US
Subject: AeroElectric-List: Re: Facet pumps: Energy vs. Flow
From: "rampil" <ira.rampil@gmail.com>
Good engineering principles favor measuring the actual parameter
you want, rather than a surrogate, especially when there is no
reliable one-to-one mapping of one to the other.
In the case of current draw, for example, overheating the coil or dirt
in the mechanism will probably change the current draw
Pressure downstream would depend on where the fill hose enters the
downstream tank, if at the bottom, or at a positive hydrostatic head, the
pressure downstream of the pump will stay positive while there is fuel
in the tank.
What about measuring fuel level in the feeding tank, is not that what you
really want to make a decision with? When it reads zero, stop pumping?
--------
Ira N224XS
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=294942#294942
________________________________ Message 3 _____________________________________
Time: 05:48:55 AM PST US
From: BobsV35B@aol.com
Subject: Re: AeroElectric-List: Facet pumps: Energy vs. Flow
Good Morning Bill,
Wow!
It appears that any suitable current measuring device will be a lot more
complex than my feeble brain can comprehend.
Thanks to you and all the others that have contributed to my on going
education.
In any case, it does seem that a few breadboard experiments are in order.
Happy Skies,
Old Bob
In a message dated 4/20/2010 6:41:53 A.M. Central Daylight Time,
sportav8r@gmail.com writes:
How about some filtering on the "input" line of the ammeter? If we're
looking at constant-amplitude square wave current pulses of varying frequency,
a capacitive filter to perform an "integral" function might give you an
average-current-over-time measurement that closely matches the frequency and
therefore the load on the pump. In practice, I am not sure from listening
to my Facet pump all these years how much the frequency changes as a
function of load. There is a sound change as it self-primes when I first hit
it
before engine-start.
Just a thought. I had to do the pneumatic equivalent (expansion chamber
plus input restrictor) to keep my manifold pressure digital readout from
jumping all around in an un-readable fashion. A little RC pi or L network
might do what you need.
Bill B.
On Mon, Apr 19, 2010 at 9:56 PM, Charlie England <_ceengland@bellsouth.net_
(mailto:ceengland@bellsouth.net) > wrote:
<_ceengland@bellsouth.net_ (mailto:ceengland@bellsouth.net) >
Certificated. Bummer.
If you think you can legally use current sensing, have you tried a
restricter in the pump's output to see if it will raise the current enough to
be
measurable vs the no-flow state?
On 4/19/2010 6:16 PM, _BobsV35B@aol.com_ (mailto:BobsV35B@aol.com) wrote:
Good Morning Charlie,
Those units by Pillar Point Electronics look very promising. As I said a
couple of messages back, I need something that can be used on a normally
certificated aircraft. Not sure about the PPE product, but I am checking into
it.
Thanks for the comment.
Happy Skies,
Old Bob
In a message dated 4/19/2010 4:50:49 P.M. Central Daylight Time,
_ceengland@bellsouth.net_ (mailto:ceengland@bellsouth.net) writes:
<_ceengland@bellsouth.net_ (mailto:ceengland@bellsouth.net) >
On 4/19/2010 3:03 PM, ROGER & JEAN CURTIS wrote:
>
> To me, they look and sound just like the ones that were used
> on those Ford gasoline fired heaters back in the thirties. But
my memory
> could be fooling me.
>
> Those were probably the Stewart Warner or Bendix pumps.
> Whadda Ya Think?
>
> If so. does that mean I need to monitor the frequency some
> how?
>
> This is getting complicated,. No wonder nobody does it!
>
> Happy Skies,
>
> Old Bob
>
> I am not sure of the application here, but I
> believe that there should be a significant pressure drop on the
output of
> the pump, when there is no longer any fuel. This being the
case, perhaps
> you could use a pressure switch, similar to what is used to
monitor engine
> oil pressure and turn on the hobbs meter, on some aircraft. You
would need
> to check the pressure differential between pumping fuel and
empty tank
> pumping, and use a switch midway between. This would be a
normally closed
> switch which would open when there is fuel flow and close, to
turn on the
> light when there is no more fuel to pump.
>
> Not sure if this is a viable option for your
> application, but might work, and is very simple. (I especially like
> simple:-)
>
> Roger
>
If you're using it as a transfer pump, there won't be a lot of
pressure
since it will be just the 'head' from one tank to the other. Often no
more than a few inches of rise, plus the resistance of the tubing.
How about one of the sensing devices using light to detect the
presence
of liquid? I bought a couple several years ago, intending to use
them to
monitor end-of-transfer from my aux tanks, then forgot to install
them.... They mount in a single hole & have a cone shaped plexi
tip. An
LED shines out through the plexi; presence/absence of liquid
changes the
light reflected back into the photocell in the same housing, changing
the state of the sense line.
If that interests you, I'll try to locate the name of the device & a
source for you.
Charlie
________________________________ Message 4 _____________________________________
Time: 06:09:04 AM PST US
Subject: RE: AeroElectric-List: Re: Facet pumps: Energy vs. Flow
From: "Jon Finley" <jon@finleyweb.net>
=0AI find this discussion very interesting and hope for an inexpensive solu
tion. I really like that Pillar Point flow detector but the price is more
than I'd like to spend.=0A =0AJust to add some data points.... In my case,
I know the fuel level in the tank but I wish to know when fuel stops being
delivered to that tank so alternate plans can be made. So, a "fuel is not f
lowing" indicator would add a level of comfort (would be "nice" but certain
ly not mandatory since I am currently flying without this).=0A =0AMore spec
ifically, I have a large main tank from which fuel is pumped into the heade
r. The header is about 5 gallons (one hour of flight time). I typically l
eave my transfer pump on all the time. If it were to stop and I didn't not
ice (which is likely), I have a warning light that will come on at about 2.
5-3 gallons. That leaves me with about 30 minutes to figure out what to do
. If I had known immediately, I would have had 60 minutes. Of course, I h
ave a backup fuel pump which I would immediately switch on. However; it ca
n take some time before seeing the fuel level start to rise. When dealing w
ith a 30 minute window, knowing now versus knowing in 5-10 minutes is a big
deal (at least in terms of my stress level - FYI, I live out west were air
ports are frequently more than 30 minutes apart).=0A=0AJon Finley=0AN314JF
- Q2 - Subaru EJ22=0A[http://www.finleyweb.net/Q2Subaru.aspx] http://www.fi
nleyweb.net/Q2Subaru.aspx=0A =0A =0A=0A-----Original Message-----=0AFrom: "
rampil" <ira.rampil@gmail.com>=0ASent: Tuesday, April 20, 2010 6:41am=0ATo:
aeroelectric-list@matronics.com=0ASubject: AeroElectric-List: Re: Facet pu
<ira.rampil@gmail.com>=0A=0AGood engineering principles favor measuring th
e actual parameter=0Ayou want, rather than a surrogate, especially when the
re is no=0Areliable one-to-one mapping of one to the other.=0A=0AIn the cas
e of current draw, for example, overheating the coil or dirt=0Ain the mecha
nism will probably change the current draw=0APressure downstream would depe
nd on where the fill hose enters the =0Adownstream tank, if at the bottom,
or at a positive hydrostatic head, the =0Apressure downstream of the pump w
ill stay positive while there is fuel=0Ain the tank.=0A=0AWhat about measur
ing fuel level in the feeding tank, is not that what you=0Areally want to m
ake a decision with? When it reads zero, stop pumping?=0A=0A--------=0AIra
N224XS=0A=0A=0A=0A=0ARead this topic online here:=0A=0Ahttp://forums.matron
================0A=0A=0A=0A
________________________________ Message 5 _____________________________________
Time: 07:51:11 AM PST US
From: BobsV35B@aol.com
Subject: Re: AeroElectric-List:
Test --- Do Not Archive
In a message dated
________________________________ Message 6 _____________________________________
Time: 07:58:18 AM PST US
From: BobsV35B@aol.com
Subject: Re: AeroElectric-List: Re: Facet pumps: Energy vs. Flow
Good Morning Ira,
I have what I consider to be relatively good fuel gauges in the tanks, but
find that there is at least a ten to fifteen minute window between where
the gauge says empty and it actually will be dry. I do not wish to turn the
pump off too soon and have fuel in the tank that has not been used and I do
not like to run the pump when it is not actually pumping fuel.
It would be very nice to be able to verify the accuracy of the fuel gauge
by noting when the pump stops pumping fuel rather than running the pump
while dry for possibly an extra ten to fifteen minutes every time I utilize the
auxiliary fuel tank.
I do have excellent fuel use measuring capability and what I do now is note
the fuel burned number when I turn on the pump and shut it off when the
amount of fuel known to be in the tank has been burned.
Nevertheless, it would be nice to know within seconds when the tank has run
dry so that the pump could be turned off.
I really would rather not be running the pump when it is not pumping fuel.
Happy Skies,
Old Bob
In a message dated 4/20/2010 7:43:50 A.M. Central Daylight Time,
ira.rampil@gmail.com writes:
--> AeroElectric-List message posted by: "rampil" <ira.rampil@gmail.com>
Good engineering principles favor measuring the actual parameter
you want, rather than a surrogate, especially when there is no
reliable one-to-one mapping of one to the other.
In the case of current draw, for example, overheating the coil or dirt
in the mechanism will probably change the current draw
Pressure downstream would depend on where the fill hose enters the
downstream tank, if at the bottom, or at a positive hydrostatic head, the
pressure downstream of the pump will stay positive while there is fuel
in the tank.
What about measuring fuel level in the feeding tank, is not that what you
really want to make a decision with? When it reads zero, stop pumping?
--------
Ira N224XS
________________________________ Message 7 _____________________________________
Time: 10:35:34 AM PST US
From: Mike Welch <mdnanwelch7@hotmail.com>
Subject: AeroElectric-List: Re: Facet pumps: Energy vs. Flow
Bob=2C
Pardon me for butting in=2C but from my experience with certificated airp
lanes=2C it is virtually impossible to get a field approval like you're aft
er.
I used to have a 1961 Cessna 172=2C with an O-300 Continental. On those
hot mid-summer California days (100+)=2C my oil temps got well into the red
on climbout!! I checked the accuracy of the gauge=2C and it was correct!
Therefore=2C I wanted to add an oil cooler to my Cessna 172. It didn't c
ome with one=2C but I could get a later model 172 oil cooler to fit. I sen
t off my Form 337 to the local FSDO=2C and their first reaction was "NO!"
Their attitude was "if it didn't come with one=2C it doesn't need one!!"
I was irritated (to say the least)=2C and requested an appeal. They fina
lly relented and said it would be okay. For crying out loud =2C it was jus
t an oil cooler!! (all certified parts=2C too)
My opinion is=3B there ain't no way you can legally add any kind of perma
nent parts to modify to your fuel pump=2C fuel lines=2C or anything else=2C
on a certificated airplane=2C without that approved 337.
Just my opinion.................
Mike Welch
From: BobsV35B@aol.com
Subject: Re: AeroElectric-List: Re: Facet pumps: Energy vs. Flow
Good Morning Ira=2C
I have what I consider to be relatively good fuel gauges in the tanks=2C bu
t find that there is at least a ten to fifteen minute window between where
the gauge says empty and it actually will be dry. I do not wish to turn the
pump off too soon and have fuel in the tank that has not been used and I d
o not like to run the pump when it is not actually pumping fuel.
It would be very nice to be able to verify the accuracy of the fuel gauge b
y noting when the pump stops pumping fuel rather than running the pump whil
e dry for possibly an extra ten to fifteen minutes every time I utilize the
auxiliary fuel tank.
I do have excellent fuel use measuring capability and what I do now is note
the fuel burned number when I turn on the pump and shut it off when the am
ount of fuel known to be in the tank has been burned.
Nevertheless=2C it would be nice to know within seconds when the tank has r
un dry so that the pump could be turned off.
I really would rather not be running the pump when it is not pumping fuel.
Happy Skies=2C
Old Bob
In a message dated 4/20/2010 7:43:50 A.M. Central Daylight Time=2C ira.ramp
il@gmail.com writes:
Good engineering principles favor measuring the actual parameter
you want=2C rather than a surrogate=2C especially when there is no
reliable one-to-one mapping of one to the other.
In the case of current draw=2C for example=2C overheating the coil or dirt
in the mechanism will probably change the current draw
Pressure downstream would depend on where the fill hose enters the
downstream tank=2C if at the bottom=2C or at a positive hydrostatic head=2C
the
pressure downstream of the pump will stay positive while there is fuel
in the tank.
What about measuring fuel level in the feeding tank=2C is not that what you
really want to make a decision with? When it reads zero=2C stop pumping?
--------
Ira N224XS
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________________________________ Message 8 _____________________________________
Time: 11:05:32 AM PST US
From: BobsV35B@aol.com
Subject: Re: AeroElectric-List: Re: Facet pumps: Energy vs. Flow
Good Afternoon Mike,
Believe it or not I do understand your frustration and the problems that
are faced when dealing with the FAA.
It is my opinion that the vast majority of the folks at FAA want to do a
good job, but are so hamstrung with regulations and paper work that it is
easier to just say no.
However, I have had fairly good luck getting local approvals from my
supervising FSDO.
As I think we can all agree, each FSDO is a kingdom unto itself and what is
easy to get approved at one office may be impossible at another.
Nevertheless, I have gotten several local approvals here locally. I do hold an
A&P
with Inspection Authorization. It does help me know who I should present the
data to and how the presentation should be made.
In general, if we can think of a way to add something that has no chance of
interfering with required equipment, the local approval has a better
chance of being approved.
Once again, the FAA has no obligation to ever issue a local approval. In
fact, if an individual inspector does issue the approval, he is doing it on
his own knowledge and is personally responsible for what happens. In many
ways it is surprising that any FAA inspector ever issues a local approval.
He/she has no obligation to do so. It is just a privilege he has been
accorded. Failure to do so does not hurt his career at all, but making a dumb
approval could end his career.
Happy Skies,
Old Bob
In a message dated 4/20/2010 12:37:05 P.M. Central Daylight Time,
mdnanwelch7@hotmail.com writes:
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.................
Mike Welch
________________________________ Message 9 _____________________________________
Time: 01:53:26 PM PST US
Subject: AeroElectric-List: Re: switch breaker on ALT field
From: "rckol" <rckol@kaehlers.com>
Switch breakers will function for this application.
I have read conflicting reports about the long term reliability of these. Some
folks end up tearing them out because they don't hold up and others have no
trouble
with them. Sorry, I don't have any brand specific recommendations. I
am not going to use them.
Dick
--------
rck
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=295024#295024
________________________________ Message 10 ____________________________________
Time: 03:38:33 PM PST US
Subject: AeroElectric-List: S704-1 on Hot Side of Firewall?
From: "Noah" <sgninc@cox.net>
I requested the spec sheet for the S704-1 relay from B&C, and it is a Tyco T9A
with an operating temp limit of 85C (185F). This seems a bit low for mounting
in the engine compartment on the firewall. where I had been planning to mount
it. I called B&C to ask them if they recommended mounting these in the engine
compartment and the gentleman I spoke with was not sure - he recommended a post
here.
Anybody know what the firewall temps can climb to?? Anybody mounted one of
these
firewall forward in an RV and had problems? Or had it last 2000 hours without
issue??
--------
Highest Regards,
Noah Forden
RV-7A
Rhode Island
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=295030#295030
________________________________ Message 11 ____________________________________
Time: 08:30:35 PM PST US
From: "Robert L. Nuckolls, III" <nuckolls.bob@aeroelectric.com>
Subject: Re: AeroElectric-List: S704-1 on Hot Side of Firewall?
At 05:36 PM 4/20/2010, you wrote:
>
>I requested the spec sheet for the S704-1 relay from B&C, and it is
>a Tyco T9A with an operating temp limit of 85C (185F). This seems a
>bit low for mounting in the engine compartment on the firewall.
>where I had been planning to mount it. I called B&C to ask them if
>they recommended mounting these in the engine compartment and the
>gentleman I spoke with was not sure - he recommended a post here.
>
>Anybody know what the firewall temps can climb to?? Anybody mounted
>one of these firewall forward in an RV and had problems? Or had it
>last 2000 hours without issue??
It will be fine. These devices and their close
cousins are used under the hood of motor vehicles
and they're fine.
The various companies I've worked for have done
numerous studies of temperature under the cowl
and found that nothing gets really all that hot
as long as it's not exposed to direct infra-red
radiation from stacks (particularly turbochargers).
I've seen some RG battery cases melted because they
were too close to exhaust pipes.
Bob . . .
________________________________ Message 12 ____________________________________
Time: 08:36:06 PM PST US
From: "Robert L. Nuckolls, III" <nuckolls.bob@aeroelectric.com>
Subject: Re: AeroElectric-List: Re: switch breaker on ALT field
At 03:50 PM 4/20/2010, you wrote:
>
>Switch breakers will function for this application.
>
>I have read conflicting reports about the long term reliability of
>these. Some folks end up tearing them out because they don't hold
>up and others have no trouble with them. Sorry, I don't have any
>brand specific recommendations. I am not going to use them.
The mil-qualified sw/breakers are fine. Actually, the
P&B W31 series are reasonably decent too. There's about
80K in service in Bonanzas and Barons since way back
when . . . and yes, a few have failed in a way that
put smoke in the cockpit . . . but those were the 30A
devices that control electric prop de-ice.
Obviously, you can't get the features in single
switches of any kind that are offered in the progressive-
transfer 2-pole toggles (2-10, 2-50, 2-70) but if your
design goals don't require this feature, then the
single switches will do.
Now, having said that, I'm not sure I'd recommend
the W31 used upstream of a crowbar ov protection system
that I designed. I've not studied the trip dynamics of
this device in that application. The miniature TI/Klixon
style breakers have been paired with our crowbar ov
systems by the thousands with good service histories.
Bob . . .
===================================
com/Navigator?AeroElectric-List" target="_blank">http://www.matronics.com/Navigator?AeroElectric-List
===================================
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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
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Subject: | Re: Diode confusion |
Check the EAA.ORG website under hints for homebuilders electrical. They have a
nice video with an instructor demonstrating exactly what you are asking about.
It will clear things up for you.
Bob S.
Sent from my iPhone
On Apr 21, 2010, at 19:41, Lincoln Keill <airlincoln@sbcglobal.net> wrote:
Getting ready to crimp a Radio Shack 1N5400 diode into a fast-on tab for my SD-8
relay control and thought -- "gee, maybe I better check this diode to make sure
it's good before I do this" -- what could be simpler? Current flows from
the non-band side of the diode to the band side, but not the other way (just like
the schematic), right? Get out the multi-meter, set it to measure ohms.
I put the red lead on the non-band side and the black lead on the band side and
expect to see zero (or very little) resistance. Uh oh....infinite resistance...not
good...do I have the leads reversed on the meter? Nope. I reverse the
leads (red on band-side and black on non-band-side...expecting to see infinite
resistance) and see...uh oh...3 milliohms. Now I'm really confused. I pull
another diode out of the packet and repeat the test....same result. I check
the heat-sinked bridge recitifier for the ebus regular feed...same result.
I believe the chance that three different components turned out defective or mis-labeled
are pretty remote and the chance that my knowledge of all things electric
is (once again) in need of improvement. Perhaps I just don't understand
how the multimeter works.
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.
Do Not Archive
Lincoln Keill
RV-7A
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Subject: | Re: Diode confusion |
Check the EAA.ORG website under hints for homebuilders electrical. They have a
nice video with an instructor demonstrating exactly what you are asking about.
It will clear things up for you.
Bob S.
Sent from my iPhone
On Apr 21, 2010, at 19:41, Lincoln Keill <airlincoln@sbcglobal.net> wrote:
Getting ready to crimp a Radio Shack 1N5400 diode into a fast-on tab for my SD-8
relay control and thought -- "gee, maybe I better check this diode to make sure
it's good before I do this" -- what could be simpler? Current flows from
the non-band side of the diode to the band side, but not the other way (just like
the schematic), right? Get out the multi-meter, set it to measure ohms.
I put the red lead on the non-band side and the black lead on the band side and
expect to see zero (or very little) resistance. Uh oh....infinite resistance...not
good...do I have the leads reversed on the meter? Nope. I reverse the
leads (red on band-side and black on non-band-side...expecting to see infinite
resistance) and see...uh oh...3 milliohms. Now I'm really confused. I pull
another diode out of the packet and repeat the test....same result. I check
the heat-sinked bridge recitifier for the ebus regular feed...same result.
I believe the chance that three different components turned out defective or mis-labeled
are pretty remote and the chance that my knowledge of all things electric
is (once again) in need of improvement. Perhaps I just don't understand
how the multimeter works.
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.
Do Not Archive
Lincoln Keill
RV-7A
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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
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Subject: | Re: S704-1 on Hot Side of Firewall? |
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
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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
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Subject: | 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
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
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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
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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@matronics.com [mailto:owner-aeroelec
tric-list-
> server@matronics.com] On Behalf Of Noah
> Sent: Wednesday=2C April 21=2C 2010 11:11 PM
> To: aeroelectric-list@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
>
>
>
>
>
>
>
> _-
> ========================
==
> =======
> _-
> ========================
==
> =======
> _-
> ========================
==
> =======
> _-
> ========================
==
> =======
>
>
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Subject: | Re: Future of general aviation |
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@aeroelectric.com> wrote:
> nuckolls.bob@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 . . .
>
>
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Subject: | Re: Surface temperature sensor |
At 03:58 PM 4/21/2010, you wrote:
>
>Do Not Archive
>
>Thanks IRA,
>
>Yes, I'll do some digging. I was thinking about something with a flat
>profile and perhaps a stick on for a flat surface. There must be
>somebody putting out a device that can be fastened to a flat surface
>that has two wires sticking out of it.
We usually use a thermocouple wire and stick it to
the surface with some epoxy. If you don't have
a thermocouple reading instrument, you can rig
a direct reading semiconductor sensor like the
the LM285. It's powered up directly from your
14v system through a 10K resistor and reads
directly in degrees Kelvin. It's in the shape
of a plastic TO92 transistor with a flat side
easily bonded to the surface of interest.
You can read it's measurement directly on
a multimeter where 2.75 volts is equal to
275 degrees K.
Very handy for a quick-n-dirty look-see.
Radio Shack and Harbor Freight both stock
temperature reading multimeters based on
type K thermocouple wire.
Bob . . .
Message 34
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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 . . .
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