Helicopter Transmission Test Box

Thread Starter

Collin Moore

Joined Mar 31, 2018
Hey everyone, first time poster. Thanks for any help in advance!

So short and sweet(ish), I'm working on building a transmission breakout/test box for a helicopter. I have most everything figured out already, except for transmission high pressure and high temperature. The goal is to have the box simulate a 100% functional transmission with no faults (metal chips, high temperature, low pressure, etc.). Most of this can be done with toggle switches, but for pressure and temperature I need to use potentiometers. My trouble is just identifying what I'll need to use. I have a modest amount of experience with electrical repair and whatnot, but more in depth design is a bit out of my area of expertise.

The signals I need to "spoof" are 10vdc input, and the returning 0-10vdc signal determines the transmission pressure/temperature based on the voltage. I'd like to get a pot that I can use to go from 0-10vdc and adjust the temperature to test the onboard equipment to make sure all the wiring is checking out.

Anyone have recommendations for pots? Ideally something that I can mount inside of a sheet metal box. Solder or pin connections are fine, I'm more interested in finding a proper one.

Thanks again all!


Joined Mar 14, 2008
Do you have a 10V supply voltage?
Do you know the impedance of the load you are driving?
Do you need to accurately know the output voltage from the pots (like a digital readout)?
Would a pot like these be mechanically okay for your use?

Thread Starter

Collin Moore

Joined Mar 31, 2018
It's 10VDC supply, yes.
No idea on the impedance.
Not really necessary, my plan was to use a multimeter and physically mark on the test box where 0v and 10v read out at, or just marking the temperature/pressure that voltage would represent.
Definitely looks good, do you have a source for that I could check out?


Joined Jan 15, 2015
In my experience with these things something you may want to consider is that the average potentiometer has about 270 degrees of rotation start to stop. The pot output on the welding machines I have worked with for setting both arc voltage and arc current work into very high impedance loads so the current through the pot is minimal, a high wattage pot is not required. Again, just my experience.

With this in mind you may want to consider a potentiometer like this one which will offer 10 full rotations and really improve your resolution. Then another nice added feature would be a knob and dial indicator with a locking feature. I linked to Amazon but any electronic parts house will have these common parts. The links are also to low cost likely Chinese manufacture parts but they should work fine.

<EDIT> I replied to the wrong thread, no clue how or why but I just figured that out?</EDIT>

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