Low Noise POTS

[knji]

Can someone recommend a high quality and very low noise potentiometer for a robotic application?

One that can be used with a very low order filter or no filter at all.

Thanks.

 

[Skogsgurra]

First; POTS usually means Plain Old Telephone System. So I was intrigued by the question about low noise. Interesting, I thought.

Back to order: Pots for robotic applications are not a good idea. The noise is not the main problem - the life is. I would look at contacless potentiometers like Hall and magnetoresistive devices. Usually, encoders and resovers are used in robotics.

 

[cbarn24050]

Hi, just look for pots designed for servo applications, there are loads to choose from but be prepared to dig deep in your pocket.

 

[knji]

skogsgurra,

I am currently using very low resolution encoders, we are talking 128 PPR. The problem is I am not using an onboard counter to compute angular rotation. I am using a non-conventional method where I sample the input pins and determine position. This is causing discontinuities in my velocity and acceleration measurements. Hence, the idea of a POT.

cbarn24050, thanks for the tip.

 

[ScottyUK]

knji,

Check out the conductive plastic potentiometers from Bourns. Example at...

http://www.bourns.com/pdfs/6674.pdf

Skogsgurra's comments are very valid. Encoders and resolvers are better for long term reliability. I have had exceptionally good results with Balluff's MicroPulse magnetostrictive sensors, but you pay for the quality.

Variohm make (relatively) low cost linear sensors using potentiometer technology. Not as good as the Balluff MicroPulse, but if ultimate accuracy, longevity and survivability aren't top priority then they are well worth a look. In my industry a totally reliable £2000 sensor is a bargain compared to a fairly reliable £200 sensor when one failure costs tens or hundreds of thousands in lost production.



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If we learn from our mistakes,
I'm getting a great education!

 

[knji]

ScottyUK,

Thanks for the link. I decided to stick with the encoders and use the onboard counter of the DAQ.