Fun With Fans

[zinge]

Hi was wondering if anyone could help - need some help with some electronic thingies.

Im trying to get standard computer fans - DC 12v 0.15A to rotate at about 20-60 rpm or similar and powering from AA batteries.

I know i need a variable resistor (pot) but im unsure of the specifics - number of batteries values of resistor etc.

Cheers

 

[Matt555]

You may need to start the fans off at their normal voltage to get them started otherwise they may not start, as for the value of the resistor it depends on what voltage you need to get them to run at 60rpm, I'm not sure of that.

Formula for working out resistance is

R=V/I

Where

V=Potential Difference in Volts
I=Current in Amps
R=Resistance in Ohms