Best source for a potentiometer?

[Gdeaver]

If your looking to determine absolute position for an arm or something, you might want to look at one of these neat devices.
http://www.gmw.com/magnetic_sensors/ametes/360ASMC.html
They could also be used instead of an encoder. A simple A to D instead of dealing with interrupts. There is a white paper that discuses the use of pots as encoders. This device would be applicable. This company also sells several development boards that include a magnet and holder. They would be idea for testing.

[RyanN]

Originally Posted by Gdeaver

If your looking to determine absolute position for an arm or something, you might want to look at one of these neat devices.
http://www.gmw.com/magnetic_sensors/ametes/360ASMC.html
They could also be used instead of an encoder. A simple A to D instead of dealing with interrupts. There is a white paper that discuses the use of pots as encoders. This device would be applicable. This company also sells several development boards that include a magnet and holder. They would be idea for testing.

This isn't what I'm really looking for. I'm adding the potentiometer to an arm, but the only place I can mount it is on the small gear on the last stage of the chain, so it will turn multiple times before the arm is raised. Thanks for the info though, I can think of other uses for this.

[vivek16]

I have heard to avoid radio shack. Digikey is used often. and they have a cool selection process.

[RyanN]

Originally Posted by vivek16

I have heard to avoid radio shack. Digikey is used often. and they have a cool selection process.

I'd also say to avoid Radio Shack. I purchased a potentiometer there for our robot last yearand I could only use about half of the rotation because it would give the same value close to the extremes of rotation.

[Alan Anderson]

Originally Posted by RyanN

I'd also say to avoid Radio Shack. I purchased a potentiometer there for our robot last yearand I could only use about half of the rotation because it would give the same value close to the extremes of rotation.

You might have accidentally purchased a "log taper" or "audio taper" potentiometer. For position sensing, a "linear taper" pot is preferred.

[Pavan Dave]

Two solutions. Either a 10 turn pot if you want or you can couple two continuous pots to cover all 0-259 degrees. I'll get part numbers for ya tomorrow.

[Gdeaver]

The Ametes absolute position sensor is ideal for arm position. It would have to be mounted on the joint. If the arm joint design does not permit mounting on the joint, It could still be used with some additional programming.

[RyanN]

I ended up ordering this potentiometer:
http://webtronics.stores.yahoo.net/73jb50k.html

Hopefully it will arrive soon and work well.