I just smoked my second potentiometer on a Leo Bodnar board, a BUx model. The pots actually sent up a wisp of smoke and smelled like burning hair. @#$%^&*!!!

What am I doing wrong?

Did I wire the voltage into the ground?

Do pots have voltage ratings? I ask because I'm using some original Boeing pots.

A multimeter tips you can give?


Flying Colander

Pots have a wattage rate. They are resistors after all. Generally their resistance is high enough that you can wire the two ends of them between the positive and negative rail without problems, using the wiper to pick up the reference voltage that will be read by the microcontroller. But if you wire one end of the potentiometer to the a voltage rail and the wiper to the other, when the wiper is turned so that the resistance between the two pins is very small the potentiometer will allow too much current through and let out the magic smoke. This can also happen if the microcontroller allows too much current through its ADC pin, but that's VERY unlikely.

Can you tell us the specifications of the pots you are using? Maybe they are not even pots, not everything with a knob on is.

Inverting +5v and Gnd wires on pot, get inverted response.

The only critical wire is "Input" - middle pin.

Thanks, Brandano and Sokol. You guys to the rescue again!

I left the electronics cool off and have come back a few days later. Looks like a simple mis-wiring mistake. I used the color of the wires I'd soldered instead of following the terminals.

I've printed out those examples you posted, Sokol.

Cheers,

Flying Colander

Wanted to add a recommendation for electronics newbies like myself. I found a great book called Hacking Electronics by Simon Monk. The book covers everything. The basics and introductory chapters are especially well written, with plenty of illustrations too, and make no assumptions about your knowledge of electronics. The books starts from zero and builds you up. Recommended for all neophytes who want the entire subject in one place.

Flying Colander

http://www.simonmonk.org/?page_id=74 Hacking Electronics