Hi Paul and everyone, I am looking for a vendor for bulkhead
connectors. I need to supply electrical power to the intank fuel pump
and need to have a sealed connector. I'm coming up empty locally and
even on the Internet. Someone has to sell these they are in every
automobile around. Any help here is greatly appreciated. T.W.
Digi Key is who you are looking for.
They carry just about everything and service is good.
What you want are Amphenol AN type aluminum shell bayonet with
gold plated pins, Page 212 Sept Dec 2004 catalog.
A size 12 pin will take 23 amps. They have them up to size
8 pins. Or .125 inch diameter wire. The smaller the number
the bigger the wire. You might have to epoxy the back
side to seal them.
www.digikey.com
BTW I was thinking a good way of backing up your electronics
is to use connectors reachable by the pilot
and have spare electronic parts in the airplane that
can be plugged in case of a primary electronic part failure.
Here is a good example. These MicroSquirt EFI computers
are just a bit larger than a Quarter coin. You could carry
two or three of them in the airplane. One fails so
unplug it and plug a new one in.
Paul Lamar ...No rotor no motor.
I would consider just cannibalizing one from a standard automobile
in-tank pump module. I've been thinking about using the whole
module. Not necessarily this one, but this one is typical. (from a
GMC Safari 4.3L, 1998).
Aubrey
Speaking of in the tank pumps Klaus Savier LSE showed
me his new aircraft EFI system. Dual units just like Tracy uses.
He controls the fuel pump speed so no fuel return line is necessary.
Paul Lamar
Paul,
You may want to rename this to: auto components for fuel or something
similar.
Maybe this is a good time to solicit opinions on the system I have in
mind that maximizes the use of modern, efficient, high reliability auto
components.
1) Dual in-tank auto fuel pump modules with integral fuel level sensors
and strainers. Use the automobile electrical connectors. Possibly use
the automobile hose connectors.
2) Fuel pressure regulation either with a conventional fuel pressure
regulator and a full flow return line or a Pulse width modulated fuel
pump speed control with a small bleed return line for air removal.
3) Fuel injection and main ignition control via a Haltech E6GMX firing
one plug per rotor. This ECU is identical to the E6X, but has
connectors to plug directly into a General Motors wiring harness and is
priced lower than the E6X. It has extra PWM outputs that can be
controlled by any of the input signals it is monitoring. It could
control a turbo wastegate and the fuel pump speed/pressure. It has full
data logging and is easy to program. Use GM ignition coils, pressure
sensors, and temperature sensors for engine control. On the airframe
use GM heater servos for flight control trim and use auto HID headlamps
for landing/taxi. A couple of salvaged GM wiring harnesses would yield
more than enough connectors for the entire aircraft. Using a consistent
set of connectors and a consistent methodology will improve reliability.
4) Redundant ignition via a separate shaft position sensor, fixed
timing, waste spark, firing one plug per rotor. Use a simple GM four
terminal ignition module. This could be changed to a flywheel mounted
magneto if such becomes available.
5) Limp home fuel system via one or two extra injectors manually
regulated by a simple PWM control circuit. This could be made
non-electrical by using a needle valve that meters fuel into the manifold.
I see little value to having two complete ECU systems because if one
fails, the only use for the backup is to land safely ASAP....not to
complete the mission.
Aubrey
Aubrey
Many fine point you brought up here.
#3. You might consider sourcing the connectors used in marine applications
that are waterproof by injecting a grease inside them prior to crimping and
heat shrinking.
#5. Excellent idea about the back-up extra non electrical needle valve
injectors. What is a PWM control circuit?
Doug in Japan
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