Potentiometer value

Hello,

Is the wirewound potentiometer in the link below good for position sensing? Does the value matter? (since the only available value is 500ohms)

**broken link removed**

Thanks.

In which application you want yo use this potentiometer? The value is important depends by application

The potentiometer will be used to monitor a motor position. The wiper of the potentiometer will be connected to the ADC of a microcontroller.

Provided your motor shaft position is within 285 degrees and doesn't change frequently that pot should be ok, but a proper shaft encoder would be more durable.

What effect can the potentiometer value have no the position sensing please?

That depends on what circuit you will use it in.

The potentiometer will be connected directly to the ADC.

You will have to supply the pot with a stable voltage between its two end terminals if you are using it as a potential divider rather than a simple rheostat. What voltage will you be using? The micro's Vdd, or a port output (the port would have to be able to source >10mA safely if Vdd=5V), or some external supply via a dropper resistor or regulator?

For a motor with constant rotation, high-speed rotation and/or rotation in excess of about 350°, your standard pot will never hold up. I'd give it no more than 24 hours of operation before something craps out. I agree with with Alec that a shaft encoder would be the way to go. It's already digital, so there's no need for an ADC; it's in Grey code, so there's no ambiguity in positioning; it can handle any speed, depending on which encoder you buy. You can roll your own encoder with a good drafting program like AutoCAD, providing as many bits of resolution as required. And making your own can eliminate any shafts within a bushing that will limit rotational speed and MTBF, as there will be little-to-no frictional losses. The most difficult part would be machining your own optical pickup bar, but that can be a fun project in itself!