Today's Message Index:
----------------------
1. 09:48 AM - stopping engine (Kenneth Johnson)
2. 10:15 AM - Re: Re: Designing a circuit (Ron Quillin)
3. 10:22 AM - Re: stopping engine (Bruce Gray)
4. 10:45 AM - Re: stopping engine (George, Neal E Capt USAF ACC 505 TRS/DOJ)
5. 11:00 AM - Re: stopping engine (Bob Borger)
6. 11:04 AM - Pitot heat switch (woxofswa)
7. 11:18 AM - Re: stopping engine (Jon Finley)
8. 11:56 AM - Re: stopping engine (Matt Prather)
9. 02:07 PM - Re: Re: Surface temperature sensor ()
10. 06:45 PM - Sil Pad For Schottky Diode (Don)
11. 06:57 PM - Looking for info on UPS AT GX-50/60/65 (DEAN PSIROPOULOS)
12. 07:40 PM - Question on PS6000/SL-10 Audio Panel (DEAN PSIROPOULOS)
13. 08:18 PM - Re: Pitot heat switch (Robert L. Nuckolls, III)
14. 09:10 PM - Narco COM11/11A/120 tray connector (okiairboss)
Message 1
INDEX | Back to Main INDEX |
NEXT | Skip to NEXT Message |
LIST | Reply to LIST Regarding this Message |
SENDER | Reply to SENDER Regarding this Message |
|
Aircraft Electrical Gurus,=0AThis subject has been presented briefly recent
ly, but I was looking for the opinion of several.- This may-have an ele
ctrical solution of not.- The question is: "What is the best way to stop
your aircraft engine?=0A=0AIn the recent past, at this site I have seen rec
ommended a switch to the fuel pump.- Turn off the fuel pump and eventuall
y the engine stops.- =0A=0AI rent Cessna 172 and the prefered way to stop
the engine is to minimize both the throttle and richness knobs by pulling
them out.- Technically, what exactly does this do?- Could I place a sim
ple ball valve on my fuel rail and phsically close it?- Is this what I do
on the Cessna 172?- The Cessna fuel is fed throught a carburetor and my
engine is fuel injected.- Does that make a difference?=0A=0AOn the automo
bile engine, when we turn off the engine, are we just closing the switch th
at provides current to the spark plugs, or is something else involved?-
- Is this what should be done for the aircraft engine?=0A=0AThanks for yo
ur advice.=0A=0AKen Johnson=0A=0A=0A=0A
Message 2
INDEX | Back to Main INDEX |
PREVIOUS | Skip to PREVIOUS Message |
NEXT | Skip to NEXT Message |
LIST | Reply to LIST Regarding this Message |
SENDER | Reply to SENDER Regarding this Message |
|
Subject: | Re: Designing a circuit |
At 17:55 4/25/2010, you wrote:
>Joe Gores not only suggested using a reed switch to sense my prop
>end of travel, he even gave me one to try! Today I went out and
>played a bit. I found that 3 winds of 18AWG causes the switch to
>close just as the motor starts to strain against the stop. So I
>used a dab of Goop to mate the wire loops to the reed switch and
>used a piece of nylon tubing as a container. I'm attaching a
>picture, but don't remember if those get through on this
>list. Doing this was a lot easier than I had imagined. It work
>great on the ground, but the weather here in MI was low IFR all day
>so no flight testing.
>
>I've already ordered the parts for the circuit Bob designed, so I'll
>be playing with that soon as well. I'll be able to have both
>methods operating in parallel.
>
> Thanks guys!
> Dennis
Not sure if this is required or not, but a word of caution from one
who's been there.
I've found, by experience, the glass envelope of reed relays can be
fragile and is susceptible to fracture by external forces on the end
leads. As we don't know how yours' is to be secured, just use care
to insure no side loads can transfer from the crimped terminals to
the interface of the lead and the glass.
For me, successful designs have always securely mounted the relay on
a board or terminal strip, and had all wires exit from strain
relieved terminals; preventing any loads to the reed relay itself.
Best---
Ron Q.
Message 3
INDEX | Back to Main INDEX |
PREVIOUS | Skip to PREVIOUS Message |
NEXT | Skip to NEXT Message |
LIST | Reply to LIST Regarding this Message |
SENDER | Reply to SENDER Regarding this Message |
|
In an Aviation carb=92ed or injected engine, the shutoff method is the
same- turn off the fuel. The reason for this is to prevent a fuel/air
mixture being left in a cylinder. If a P lead wire is broken and the
propeller is turned, it could fire and injure someone. From your
question I assume you=92re installing an auto engine.
Auto engines kill the spark. Some might also kill the pressure in the
fuel rail. You=92re going to have to blas=E9 your own trail here.
Bruce
www.Glasair.org
-----Original Message-----
From: owner-aeroelectric-list-server@matronics.com
[mailto:owner-aeroelectric-list-server@matronics.com] On Behalf Of
Kenneth Johnson
Sent: Tuesday, April 27, 2010 12:45 PM
Subject: AeroElectric-List: stopping engine
Aircraft Electrical Gurus,
This subject has been presented briefly recently, but I was looking for
the opinion of several. This may have an electrical solution of not.
The question is: "What is the best way to stop your aircraft engine?
In the recent past, at this site I have seen recommended a switch to the
fuel pump. Turn off the fuel pump and eventually the engine stops.
I rent Cessna 172 and the prefered way to stop the engine is to minimize
both the throttle and richness knobs by pulling them out. Technically,
what exactly does this do? Could I place a simple ball valve on my fuel
rail and phsically close it? Is this what I do on the Cessna 172? The
Cessna fuel is fed throught a carburetor and my engine is fuel injected.
Does that make a difference?
On the automobile engine, when we turn off the engine, are we just
closing the switch that provides current to the spark plugs, or is
something else involved? Is this what should be done for the aircraft
engine?
Thanks for your advice.
Ken Johnson
Message 4
INDEX | Back to Main INDEX |
PREVIOUS | Skip to PREVIOUS Message |
NEXT | Skip to NEXT Message |
LIST | Reply to LIST Regarding this Message |
SENDER | Reply to SENDER Regarding this Message |
|
Depends on the engine and the application. On most certificated systems,
pulling the mixture shuts off the fuel flow in the metering device
(injection servo or carb) - thus the term Idle Cut-Off (ICO). The fuel
servo manufactured by Airflow Performance, popular among the experimental
crowd, DOES NOT completely stop fuel flow at the low idle stop. Airflow
Performance incorporates a valve to shut off fuel between the servo and the
distribution spider.
Generally speaking, to shut down an aircraft engine we turn off the fuel
supply to starve the engine. The idea is to get the fuel out of the intake
system so that a hot cylinder or un-grounded mag won't fire unexpectedly and
hurt someone. I've had more than one airplane fire a cylinder when
positioning the prop after a run-up for maintenance - with the mags off and
keys in my hand.
Just turning off the ignition is no guarantee and leaves fuel in the system.
Hot aircraft engines will diesel, and the higher the compression, the more
likely it is to happen.
Neal
A&P/IA
-----Original Message-----
On Behalf Of Kenneth Johnson
Aircraft Electrical Gurus,
This subject has been presented briefly recently, but I was looking for the
opinion of several. This may have an electrical solution of not. The
question is: "What is the best way to stop your aircraft engine?
In the recent past, at this site I have seen recommended a switch to the
fuel pump. Turn off the fuel pump and eventually the engine stops.
I rent Cessna 172 and the prefered way to stop the engine is to minimize
both the throttle and richness knobs by pulling them out. Technically, what
exactly does this do? Could I place a simple ball valve on my fuel rail and
phsically close it? Is this what I do on the Cessna 172? The Cessna fuel
is fed throught a carburetor and my engine is fuel injected. Does that make
a difference?
On the automobile engine, when we turn off the engine, are we just closing
the switch that provides current to the spark plugs, or is something else
involved? Is this what should be done for the aircraft engine?
Thanks for your advice.
Ken Johnson
Message 5
INDEX | Back to Main INDEX |
PREVIOUS | Skip to PREVIOUS Message |
NEXT | Skip to NEXT Message |
LIST | Reply to LIST Regarding this Message |
SENDER | Reply to SENDER Regarding this Message |
|
Subject: | Re: stopping engine |
Ken,
What kind of engine are you using or planning to use? Makes a difference.
My Rotax 914 is shut down by shorting the ignition module output to ground preventing
spark. This method ensures you know that the ignition is properly grounding.
Traditional aircraft engines such as Lycoming and Continental are shut down by
setting the throttle to idle and pulling the mixture control to Idle/cutoff.
This shuts off the fuel going into the engine from either the carb or F/I system.
Makes the engine safe as described by Bruce Gray.
Auto engines are shut down by turning off the key which removes the electrical
source from the ignition, computers & fuel pump, shutting things down all over
the place.
There are valid reasons for each method. You should determine what would be best
for your engine based on the manufacturers recommendations. If you are doing
an automotive conversion, I guess you'd use the automotive method.
Bob Borger
Europa XS Monowheel, Rotax 914 w/ Intercooler, Airmaster C/S prop.
Building a Little Toot Sport Biplane.
On Tuesday, April 27, 2010, at 11:45AM, "Kenneth Johnson" <kjohnsondds@yahoo.com>
wrote:
>
Message 6
INDEX | Back to Main INDEX |
PREVIOUS | Skip to PREVIOUS Message |
NEXT | Skip to NEXT Message |
LIST | Reply to LIST Regarding this Message |
SENDER | Reply to SENDER Regarding this Message |
|
Subject: | Pitot heat switch |
I'm installing a Dynon heated pitot probe in my RV-10. I also have Van's rv-10
wiring kit. In the kit, on some circuits they use a switched circuit breaker and
others they use a switch and a separate breaker. Dynon recommends a 15 amp
breaker.
Would it be better to use a switched breaker or a switch and c/b?
Thanks in advance.
--------
Myron Nelson
Mesa, AZ
Emp completed, QB wings completed, legacy build fuse in progress
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=295891#295891
Message 7
INDEX | Back to Main INDEX |
PREVIOUS | Skip to PREVIOUS Message |
NEXT | Skip to NEXT Message |
LIST | Reply to LIST Regarding this Message |
SENDER | Reply to SENDER Regarding this Message |
|
=0A=0AHi Ken,=0A =0AI too have seen that discussion. For clarity - all of
my comments are in regards to an automotive multi-point EFI engine (not to
be confused with any carbureated engine or any mechanical fuel injection sy
stem).=0A =0AWith my flying Subaru EJ-22, the ignition switch cuts power to
the ECU (Real World Solutions EC2), injectors, and coils. Has worked fine
for 300 hours.=0A =0AI believe (but am not 100% positive) that most modern
automotive EFI systems all shut down the ECU, coils, and injectors when sw
itched off. Talking specifically about automotive EFI engines, I see no va
lue in starving the engine for fuel. I am told (but have no statistics or t
ests to prove) that this can harm a high pressure EFI fuel pump (running it
dry).=0A =0AJon=0A=0A=0A-----Original Message-----=0AFrom: "Kenneth Johnso
n" <kjohnsondds@yahoo.com>=0ASent: Tuesday, April 27, 2010 10:45am=0ATo: ae
roelectric-list@matronics.com=0ASubject: AeroElectric-List: stopping engine
=0A=0A=0A=0AAircraft Electrical Gurus,=0AThis subject has been presented br
iefly recently, but I was looking for the opinion of several. This may hav
e an electrical solution of not. The question is: "What is the best way to
stop your aircraft engine?=0A =0AIn the recent past, at this site I have s
een recommended a switch to the fuel pump. Turn off the fuel pump and even
tually the engine stops. =0A =0AI rent Cessna 172 and the prefered way to
stop the engine is to minimize both the throttle and richness knobs by pull
ing them out. Technically, what exactly does this do? Could I place a sim
ple ball valve on my fuel rail and phsically close it? Is this what I do o
n the Cessna 172? The Cessna fuel is fed throught a carburetor and my engi
ne is fuel injected. Does that make a difference?=0A =0AOn the automobile
engine, when we turn off the engine, are we just closing the switch that pr
ovides current to the spark plugs, or is something else involved? Is this
what should be done for the aircraft engine?=0A =0AThanks for your advice.
or?AeroElectric-List] http://www.matronics.com/Navigator?AeroElectric-List_
========================
Message 8
INDEX | Back to Main INDEX |
PREVIOUS | Skip to PREVIOUS Message |
NEXT | Skip to NEXT Message |
LIST | Reply to LIST Regarding this Message |
SENDER | Reply to SENDER Regarding this Message |
|
I think it's worthwhile to be precise (reduce ambiguity) in matters such
as this.
I believe many (most?) light airplane POH's specify that engine shutdown
is accomplished by moving the mixture control to idle-cutoff (ICO).
Usually this causes the engine to stop running fairly rapidly - in a
matter of a couple of seconds. Selecting rich mixture and hitting the
starter usually allows the engine to restart very quickly/easily.
Certainly many airplanes still have Stromberg carbs (or similar) which
don't have a mixture control effective enough to cause "idle-cutoff". I
have ridden with pilots of such airplanes who only use the magneto
switches to stop the engine. One benefit of this procedure is that you
check to see if you have a "hot mag" on each flight. If the engine stops
dead, you can be somewhat certain that the p-lead circuit is in working
condition.
Most (all?) light airplanes also have at least one fuel control valve
(selector), which can also be used to stop the flow of fuel to the engine.
On the carbureted engines that I have operated, closing this fuel valve
does eventually stop the engine, though depending on how low the throttle
setting is, it might take a few minutes for the float bowl in the carb to
get low enough to cause the engine to lean-out and die. Usually when I
pull up to a parking spot, I don't feel like waiting for the carb to
empty, so I never do this.
If the fuel valve was turned off, on carbureted airplanes with gravity
feed fuel, turning on the fuel valve and waiting a few moments will refill
the carb float bowl, at which point the engine may be restarted. For an
airplane with pump driven fuel, turning on the electric pump will allow
restarting much faster/sooner than if only the engine driven pump is used.
Turning on the electric pump is often in the engine start procedure.
In an airplane that depends on a high pressure electric pump, I'm not sure
it makes sense to "turn off the fuel," if that implies closing some kind
of fuel valve. It might make more sense to turn off the electric pump(s).
My impression of automotive fuel injection is that turning the key off
stops power to both the ignition and the fuel pump(s). This leaves
burnable mixture in the cylinders and intake manifold. In an airplane,
this method of stopping the engine increases the risk of unexpected prop
motion. Turning the key to run causes the fuel pump(s) to run until the
specified system pressure is reached, at which point the pump(s) turn off.
One other thing I have noticed is that some electronic ignition systems
may fire the spark plugs one time when the system is energized. This will
likely cause the prop to turn if there is a burnable mixture in the
cylinders. In fact, my Varieze has such a system. A number of times I
have actually had the engine start spontaneously because of this effect -
prime with accelerator pump, walk the prop to pull fuel into the
cylinders, turn on the ignition, and away it goes. So, magnetos aren't
the only things that will fire unexpectedly. In fact, a mag without an
impulse couple isn't likely going to spark on its own..
So to get back to the original question, I agree that stopping the fuel
delivery in some way is generally a good idea. I think turning off the
pumps while leaving the ignition firing is the best bet, as that should
dump fuel system pressure, and yield the least burnable mixture in the
cylinders.
With all that said, everyone working around aircraft should be very
careful of the propeller, whatever method is used to stop the engine.
Pilots need to be vigilant to not allow anyone to haphazardly move the
prop or stand in the prop arc.
Regards,
Matt-
> In an Aviation carbed or injected engine, the shutoff method is the
> same- turn off the fuel. The reason for this is to prevent a fuel/air
> mixture being left in a cylinder. If a P lead wire is broken and the
> propeller is turned, it could fire and injure someone. From your
> question I assume youre installing an auto engine.
>
> Auto engines kill the spark. Some might also kill the pressure in the
> fuel rail. Youre going to have to blas your own trail here.
>
> Bruce
> www.Glasair.org
> -----Original Message-----
> From: owner-aeroelectric-list-server@matronics.com
> [mailto:owner-aeroelectric-list-server@matronics.com] On Behalf Of
> Kenneth Johnson
> Sent: Tuesday, April 27, 2010 12:45 PM
> To: aeroelectric-list@matronics.com
> Subject: AeroElectric-List: stopping engine
>
> Aircraft Electrical Gurus,
> This subject has been presented briefly recently, but I was looking for
> the opinion of several. This may have an electrical solution of not.
> The question is: "What is the best way to stop your aircraft engine?
>
> In the recent past, at this site I have seen recommended a switch to the
> fuel pump. Turn off the fuel pump and eventually the engine stops.
>
> I rent Cessna 172 and the prefered way to stop the engine is to minimize
> both the throttle and richness knobs by pulling them out. Technically,
> what exactly does this do? Could I place a simple ball valve on my fuel
> rail and phsically close it? Is this what I do on the Cessna 172? The
> Cessna fuel is fed throught a carburetor and my engine is fuel injected.
> Does that make a difference?
>
> On the automobile engine, when we turn off the engine, are we just
> closing the switch that provides current to the spark plugs, or is
> something else involved? Is this what should be done for the aircraft
> engine?
>
> Thanks for your advice.
>
> Ken Johnson
>
>
Message 9
INDEX | Back to Main INDEX |
PREVIOUS | Skip to PREVIOUS Message |
NEXT | Skip to NEXT Message |
LIST | Reply to LIST Regarding this Message |
SENDER | Reply to SENDER Regarding this Message |
|
Subject: | Re: Surface temperature sensor |
I'll second that - Jim, thanks for the due diligence. I'm not that
creative at this point so I found a relatively low cost source for a 4
channel display which supports standard thermocouples and can also be
panel mounted. While not their main business, these folks seem keen
towards supplying the aircraft market. http://www.omega.com is sort of a
go-to joint for thermo-stuff. Of course there are hundreds of other
options.
http://www.aprsworld.com/thermok/
Glenn
-----Original Message-----
From: owner-aeroelectric-list-server@matronics.com
[mailto:owner-aeroelectric-list-server@matronics.com] On Behalf Of
user9253
Sent: Sunday, April 25, 2010 9:32 AM
Subject: AeroElectric-List: Re: Surface temperature sensor
<fran4sew@banyanol.com>
Jim McCulley,
Good job making an economical and accurate multi-point temperature
sensor and indicator. I admire your ingenuity and resourcefulness.
Joe
--------
Joe Gores
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=295622#295622
Message 10
INDEX | Back to Main INDEX |
PREVIOUS | Skip to PREVIOUS Message |
NEXT | Skip to NEXT Message |
LIST | Reply to LIST Regarding this Message |
SENDER | Reply to SENDER Regarding this Message |
|
Subject: | Sil Pad For Schottky Diode |
Bob,
I bought a Schottky Diode from you roughly one year ago. I installed it
today and was unable to get the device mounted so that there was no
conductivity between the load screw and the mounting plate. I did not use
excessive force on the screw and the holes are all clean. I think the Sil
Pad got damaged in the install. Can I buy another one from you ?
Message 11
INDEX | Back to Main INDEX |
PREVIOUS | Skip to PREVIOUS Message |
NEXT | Skip to NEXT Message |
LIST | Reply to LIST Regarding this Message |
SENDER | Reply to SENDER Regarding this Message |
|
Subject: | Looking for info on UPS AT GX-50/60/65 |
Has anyone with a UPS AT GX-50/60/65 panel mount GPS been able to change the
ground speed readout from knots to MPH? I'm trying to finish a ground speed
calibration series and it would be easier if the flight instruments and GPS
had the same speed readouts. I looked through the installation and
operating manuals and didn't find any information on changing KNOTS to MPH.
Anyone ever done this? If so how did you do it?
Dean Psiropoulos
RV-6A N197DM
Flying and finishing touches
Message 12
INDEX | Back to Main INDEX |
PREVIOUS | Skip to PREVIOUS Message |
NEXT | Skip to NEXT Message |
LIST | Reply to LIST Regarding this Message |
SENDER | Reply to SENDER Regarding this Message |
|
Subject: | Question on PS6000/SL-10 Audio Panel |
My PS engineering 6000 (mfg for UPS AT as the SL-10 MS) intercom has stereo
audio inputs and outputs. The other day I was flying and finally plugged in
my Sandisk mp3 player to enjoy some music while working my airspeed
calibration runs. I had the Sandisk volume set at maximum and had to have
the volume on the PS 6000 at 3/4 maximum to hear the music at a low level.
Also the music sounded a little distorted (not too surprising given the
volume setting on the 6000). I was hoping that there would be a pot on the
circuit board that I could adjust to increase the input sensitivity but
couldn't find anything in the manual about it. The system is set up for
stereo but right now I'm running the mono Sigtronics headset that I
purchased during my "Cessna" days, I have the volume on the headset at
maximum when doing the above test. The 6000 manual says it's ok to plug in
mono headsets so I doubt that the system has been damaged in any way.
Anyone have some words of wisdom on running mp3 and other audio input
devices with aviation intercoms and audio panels? I assumed the audio
inputs needed high level (not speaker level inputs) but maybe the Sandisk
just doesn't have enough oomph. In the short term I plan to convert the mono
headset to Stereo, long term I plan to purchase an ANR Stereo headset of
excellent quality (and unfortunately price). Please advise. Thanks.
Dean Psiropoulos
RV-6A N197DM
Flying and finishing touches
Message 13
INDEX | Back to Main INDEX |
PREVIOUS | Skip to PREVIOUS Message |
NEXT | Skip to NEXT Message |
LIST | Reply to LIST Regarding this Message |
SENDER | Reply to SENDER Regarding this Message |
|
Subject: | Re: Pitot heat switch |
At 01:02 PM 4/27/2010, you wrote:
>
>I'm installing a Dynon heated pitot probe in my RV-10. I also have
>Van's rv-10 wiring kit. In the kit, on some circuits they use a
>switched circuit breaker and others they use a switch and a separate
>breaker. Dynon recommends a 15 amp breaker.
>Would it be better to use a switched breaker or a switch and c/b?
Your choice. I perceive no difference in
performance.
Bob . . .
Message 14
INDEX | Back to Main INDEX |
PREVIOUS | Skip to PREVIOUS Message |
NEXT | Skip to NEXT Message |
LIST | Reply to LIST Regarding this Message |
SENDER | Reply to SENDER Regarding this Message |
|
Subject: | Narco COM11/11A/120 tray connector |
This might not be the right forum but I am looking for qty 2 of the Narco 15 pin
white Molex tray connector for the COM11/120 series radios. I am building a
ground based air boss radio rig and can't find connectors anywhere. Can find
trays but none of them have connectors so far.
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=295967#295967
Other Matronics Email List Services
These Email List Services are sponsored solely by Matronics and through the generous Contributions of its members.
-- Please support this service by making your Contribution today! --
|