Best source for a potentiometer?

What is the best place to buy a potentiometer?

What my team has used for the past couple of years have been 100K ohm pots from radioshack. We have had no trouble with them, and they are cheap and available.

Have fun,

I like to order things from Newark… but that is just a personal preference.

I used the potentiometers listed below two years ago and will be using them again this year. They are NOT cheep, but they are high precision with a long mechanical life (if I remember correctly they are 1% linearity).

Vishay Spectrol # 157-11-103
Newark # 93F9213

They run about $16.00 ea.

Electronix Express carries a variety of potentiometers.

PLTW uses Electronix Express.

You can contact them at: www.elexp.com phone:800-972-2225

In the off-season, 1293 bought some pots from Radio Shack to control our bubblemaker. Now, there may have been 343 different things that caused it, but we couldn’t get the pots to give good information consistently. It’d hold at the setting, then jump to 254 or 0 or some other crazy signal.

Just a warning for 'ya–your mileage may vary.

We also tried one pot last year that didn’t sweep 360-degrees – it had a huge dead spot where it read infinite resistance. Something new to worry about.

I have found that Radio Shack potentiometers are very inaccurate and poor in quality. I would recommend Bourns potentiometers which can be found from any of the major on line electronics retailers: Digi-Key, Newark, Mouser.

Thanks a lot.

In the past, when using continuous turn pots (which will have an open position) we use a 1Mohm (or larger) pull-up (or pull-down) resistor which will ensure that there are no floating voltages and will not drastically effect the resistance.

I want to point out too, that there are multiple types of pots. Two major types ore linear taper and audio taper, for the most part linear taper pots are best for use in many FIRST designs.

Radio Shack is good if you need them NOW, otherwise Digikey and/or Mouser.

I buy our components from Jameco. Check out their website at www.jameco.com and ask for a free catalogue. There pots are cheap but reliable. Plus they will send you the mounting hardware.

Here’s another question for the matter, and for future reference, I’ll ask two questions… I’m not sure of what to really ask. I want to know the resistance of ohm value, like 500ohm, 5k, 50k, 500k etc…

What is the best type of potentiometer to get if you only want one turn?

What is the best type of potentiometer to get if you want a mulitturn(my primary question for a 10 turn since they seem to be the most common multiturn)?

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.

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.

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

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.

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.