Potentiometer question

[antknee]

I bought two potentiomeers recently, they are both 10K rotary made by the same company. Initially the only difference appeared that relative to the board one has the rotary dial flat, the other upright. The first worked as expected with pin1 - signal in, pin 2 - signal out, pin 3 - ground. The second doesn't work at all with pin 3 connected to ground.

I'm presuming the pins were switched so pin 2 is ground now? Is there supposed to be a standard configuration?

It does seem to work with pin 3 disconnected and no ground at all, will just leaving it like that make any difference?

Thanks.

 

[bychon]

Whether it makes a difference depends on the rest of the circuit. Meanwhile, presuming doesn't work. You need to measure things or read the datasheets to figure out how to connect them.

 

[MikeMl]

Do you need it hooked up as a Potentiometer or Rehostat?

 

[crutschow]

It depends upon what you want the potentiometer to do. If you are using it as a potentiometer (such as a volume control) then you need all pins connected. If you are using it as a rheostat, then one of the fixed pins can be unused.

You can determine the pinout with an ohmmeter. Two of the pins will have a fixed resistance with dial rotation, the third one will vary.

 

[Sceadwian]

Check the resistance using an ohm meter (with nothing else attached) you should read 10K between two leads no matter what position the dial is in, these are your voltage in and ground wires, the third wire should read a variable resistance from 0-10k when referenced to either the in or ground wire (the 'in' and 'ground' wires are actually interchangeable)

It sounds like one of your units might be a potentiometer (because it works like one) and the other one is actually a rheostat, which would require an additional fixed resistor to act as a voltage divider which seems to be what you want.

Can you explain what you're trying to do? There may be a better way than what you're currently attempting.

 

[antknee]

I'm using it as a variable resistor/rheostat. I didn't know there was a difference between usage as a potentiometer and rheostat. Now I do, I can just leave pin 3 disconnected.

 

[antknee]

I did just check both pots with an ohm meter and they have switched the pins. I will remember to check in future unless I have exactly the same model.