Matronics Email Lists

The builder or experienced pilot will know how the switches work.
A new pilot might think,
"If the switch is off, then no electricity is going to the valve, so it must be open."
or
&quo ...

How will the switches be labeled for the wing tank solenoid valves?
Attached is one possibility.

After thinking about it, one could accomplish the same thing without installing a
momentary push button switch by pulling the circuit breaker for the fuel level
switches and then resetting it, ass ...

I added a momentary push button switch to the circuit (circled in red).
You will have to decide if this added feature is worth the risk of the switch
failing and causing the valves to short cycle o ...

Pete,
It seems that you want do away with the manual mode and make the center
switch position automatic just like the top position.
Why not just use a 2 position switch, OFF and AUTOMATIC?
Anoth ...

I am not necessarily recommending dual relay control of wing tank valves.
But I have attached a dual relay option.
If automatic pumping from one tank is lost due to relay failure, then automatic
pu ...

Billski, Thanks for your input.
I like your idea of venting the main tank back to the wing tanks.
And I agree that Failure Modes and Effects Analysis is a good idea.
It is my understanding that the ...

The OP wants a warning light to come on if the main fuel tank low level sensor
has not reset after 20 seconds. Amazon has a timer relay that should do it.
It has both high and low input triggers.
...

Below is a schematic of the Viper Jet mail fuel tank level control.
It was confusing to draw because the valves are normally open.
Power is applied to close the valves.
The low fuel bingo light fea ...

Simple relay circuit attached.

After thinking about it, why use an AND Gate?
The upper liquid level switch could energize the relay.
The relay can hold through the lower liquid level switch.

Eric,
What do you think of the attached circuit? It uses discrete components. No computer necessary. Integrate it with your switch circuit.

OK, I modified my drawing in post number 5 by moving the lower fuel level
sensor from the bottom of the tank to a higher position.

Pete, you wrote in a previous post, "The goal is to always keep the main tank
full until the wings are empty". That seems reasonable. It is hard for me to
understand how the fuel comp ...

Pete,
Do the wing tanks have level sensors as part of the automatic fuel transfer system?
Do each of the fuel tanks have level sensors that are not part of the automatic transfer system
but connec ...

I redrew the hydraulic circuit in my post above. The new version is based on a sketch that Pete emailed to me.
Is it accurate Pete? Is it pretty? Smile

Pete, I made a diagram of the Viper Jet fuel system based on my interpretation
of your description. It is unlikely that I got it right. Please make corrections.
Understanding how the system is ...

Below are a couple of links to websites about the Viper Jet for anyone interested.

https://youtu.be/t_QnUYNVE-U

https://en.wikipedia.org/wiki/Viper_Aircraft_ViperJet

What is the make and model of this aircraft?
Is it factory made or experimental?
Is the fuel gasoline or diesel?
What fuel pressure does the engine require?
Have you considered using a manual 4 po ...

The OP sent me a private email. He indicated that there are two continuous
duty contactors, only one used at a time. Which ever one is energized will
carry starter current and aircraft load. He ...