I'm trying to check the continuity of some potentiometers that I have. These pots are 250K and when I test them, the only time I get any valid reading > 0 ohms is when I have the pot turned all the way until it stops. Should I be getting readings as the resistance increases, such as 57K, 60K, 100K, 175K, 200K, 243K, 250K (each value being displayed as I turn the knob)??
Checking Continuity of Potentiometers
Sep 13, 2005
4 Replies
The resistance between the end terminals should be 250K, regardless of the position of the wiper.
The resistance between the wiper and either end should vary continuously between 0 and 250K as you adjust the pot.
Peter Bennett VE7CEI
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As others have said, yes, between the wiper and one end. Do these pots have integral switches, and are you measuring across one end of the pot and the switch?
Mark L. Fergerson
If you measure from an end terminal to the center (wiper) terminal, you should see a smooth change in resistance as you turn the shaft. If you measure between the two outside terminals, you should see a fixed resistance, regardless of shaft position. You have to be using an ohm meter range high enough to tell that resistance from an open circuit.
yes, typically. if these pots have three terminals the outer two should show a fixed resistance and the middle one shold vary its resistance between the two end points.
If you have semi-logarythmic pots (marked 250K-A or A250K or "LOG" etc ) most of the resistance change will be at one end of the turning
Bye.
Jasen
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