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Unread 25-01-2005, 09:32
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Re: Potentiometer Trouble ??

Quote:
Originally Posted by dez250
A few other notes when you go looking for a pot. Theres a couple major things to think about when purchasing a potentiometer from anywhere. These include whether you want an audio taper or linear taper pot and also whether you want "10-turn" or single turn pot.
Indeed. It's worth a bit of time getting a decent pot, since while you can prototype with an el-cheapo pot, once you've got the bot together, make sure you are using a nice pot.

Cheap pots have a lot of problems. The big ones are drift and non-linearity. Minor problems include poor resolution and directional hysteresis (giving a different value whether you turned the pot CW or CCW to get there).

I've usually used fairly high-end ($11 or so) 10K pots from digi-key (look up part number 6639S). Good linearity, little drift. They are single turn with no stop (so they wrap around from 10 kOhm back to 0 ohm at 0 degrees), but other than that they've been very, very reliable.