Can wires touch cards?

dj_ivocha on 19/6/2009 at 21:25

Quote Posted by TBE

(http://www.radioshack.com/product/index.jsp?productId=2102789) potentiometer. (Basically, a volume knob)

That potentiometer is not the best one for the purpose. You want a more powerful one - depending on your fan(s), a 5 Watt one should be fine. Also 5 kOhm is way too much - 100 or 200 Ohms will be a lot better. With a 5K one you'll only be able to effectively control the speed within maybe 10-30 degrees out of the possible 270 degrees rotation - the rest of the way the resistance would get too high and you won't get nearly enough juice for the fan to even start spinning.

Also if you DIY, make SURE you connect the two stationary pins of the potentiometer to the +12V and Ground leads of your power supply, and the variable lead and again the ground lead to your fan.