blueflyer

blueflyer

Well Known Member
I bought this linear pot thinking I could use it for a DIY pitch trim position indicator. Now that I have it, I can not understand how to wire it up. Can someone explain it? I would think the red wire would go to my position light on my panel and either yellow or green would go to +12v and ground respectively?? The wiring diagram in the photo is what came with the linear pot. Its sad I can become so confused over 3 wires...

 
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My guess is that you've swapped the yellow and red on the diagram. But it's just a guess. Put an ohmeter on 2 leads at a time, move the end, then you'll know for sure. As already asked, what is the device driving, and what is its total resistance?
 
Applying 12 volts directly to a pot will likely burn it up when the pot is adjusted to one extreme or the other. Do you have any documentation for the position indicator?
 
Its a 50K pot. Its going to drive the position indicator on my D120. Thank you both for asking. That made me go to the Dynon D120 install manual and it shows you how to connect the pot. That wouldn't have struck me to do that for several days otherwise.
Here is the data sheet: https://www.bourns.com/pdfs/3046.pdf

uh oh, I better get with dynon to see if a 50K pot will work. The D120 manual only lists up to 20K.
 
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Yellow to 5V excitation pin on D120
Green to Ground pin of choice on D120
Red to General Purpose input pin on D120.
50k should be fine. It's just a voltage divider. The D120 input impedance should be pretty high, but you can calibrate the error out regardless.
 
Thank you Mike.

fl-mike said:
Yellow to 5V excitation pin on D120
Green to Ground pin of choice on D120
Red to General Purpose input pin on D120.
50k should be fine. It's just a voltage divider. The D120 input impedance should be pretty high, but you can calibrate the error out regardless.
Click to expand...
 
Use your multi-meter to measure the resistance. It should be fixed between the two terminals and variable relative to the third. When measuring from the third terminal to one of the other two the resistance will go to zero at one extreme of motion. As you push it in the resistance will get high between two of the terminals and lower between the other two. Or vice versa.
 
rapid_ascent said:
Use your multi-meter to measure the resistance. It should be fixed between the two terminals and variable relative to the third. When measuring from the third terminal to one of the other two the resistance will go to zero at one extreme of motion. As you push it in the resistance will get high between two of the terminals and lower between the other two. Or vice versa.
Click to expand...

Yes, this is correct.

If your indicator reads backward to the surface travel, reverse the input power to the other end of the fixed resistance.
 
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