Have questions about FETS, transistors, measurement, power supplies, or anything else electrical?

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By QuickFix
  • Get yourself a multimeter (a cheapy Chinese one from the dollar store is just fine)
  • Set its range to Ω (= "Ohm") and start with, lets say, 200k (you won't fry anything if you chose the wrong Ω-range)
  • Put the red lead in the V/Ω input and the black lead in the "Common" input
  • Turn on the meter
  • Test the meter: put the metal contacts of the leads to each other: the meter should show (around) 0 Ω
  • Put one lead (doesn't matter which one) on the left pin of the potentiometer and the other on the right pin (the middle pin can be left loose)
  • The value shown in the display of your meter is the potentiometer value you're after; it could be off by a few ohms though, so pick a potentiometer that had a round value slightly lower than what you measure
  • If your meter shows "OL", chose a higher resistance value on the meter, when you get a very low value (or "I"), you might want to try a lower value
User avatar
By davydnorris
#92741 To add to that, set the pot to half way and measure between the middle and one of the ends.

If the value is half the total then you want a linear pot, if it's not then you want a logarithmic pot. There are such things as reverse log pots but they are not very common.