Stir Plate Potentiometer Question.No go.

I can run service lines, panels and wire a house, but electronics.... not so much. I have made a couple stir plates and have just up-graded to a bigger fan. I wanted to add a speed control so it would stop throwing the bar but I am having trouble.

I took a "a500k" Pot out of my gutar parts box and wired it in. I assumed it was three way because it had 3 legs and was a "tone" control working with two other controls. I can turn the power switch on but when I turn the Pot up the fan just turns on. I feel like it slows down when I turn it down, but then it stops.

Is it that the Pot's range is too low to allow such adjustment?
Is it my wiring?

Thanks.

Just finished a brew session, it is late and I drank a couple home brews during the session. That said, 500K sounds like too much resistance for this. Someone just posted the recommended Radio Shack component a few days ago. Yeah, it pops on when you get the current flowing OK (this is not unusual since it takes a minimum to get started) and you probably do get some speed control from it as you back it down.

quick search: I use a potentionmeter (variable resistor), part #271-215 at radio shack to adjust ... it accross the top of your stir plate where the magnet is on the fan. ...


25 ohm 3 watt Rheostat (aka Potentiometer): Part number 271-265 - $3.99 from the original post in the thread.

Sweet. Thanks man, I'll pick one up. Dont know why I couldn't find that.

Thanks to many folks on this forum (borrowing ideas), I made a stir plate last year for about $2.00 (not including the stir bar). For speed control, I came upon a happenstance around Christmas. I was setting up a train around the good 'ole Christmas tree, and as I turned the lever to make the train go faster, my brain immediately jumped to brewing and how I might be able to use an unused transformer (I had two) as the speed control to the stir plate fan! I hooked it up, mounted it to the outside of the stand, and sure enough, I have variable speed on the fan and hence that nice stir bar. Works like a dream, is safe, and was free!