How can I control the speed of my 12 volt fans? I have a 1000ma 12volt wall wart to supply the power to my fans and would like to be able to slow them down, if temperature permits, to cut back on noise. Would an AC light dimmer switch before the transformer do the job or would that fry it?

Notice, I may be completely wrong but i think adding the dimmer before the transformer would control the AC going to the transformer, not the DC going to the fan. I'm not sure how dimmer switches work, but could you use it after the transformer in line to the fan? you may want to look at computer hardware stores and get a computer fan controller:

http://www.tigerdirect.com/applications/Se...mp;keywords=fan

http://www.tigerdirect.com/applications/Se...8&CatId=501

radioshack 25ohm 3watt adjustable rheostat

http://www.radioshack.com/sm-see-all-needs...pi-2062299.html

Thanks guys! I'm not sure how to work with those Rheostats so I went with the Apevia fan controller. Just in time too as they are no longer available from this site. I must have got the last one!