I recently bought something I really don't need. I have this facination with big fans that push a lot of air. I bought the 120mm delta fan. 220 CFM!!! It is a monster. It is also almost 3 amps and I have looked just about everywhere for a rheostat, or potentiometer that can handle it. I can't find one anywhere. Does anybody know of any and where I could purchase one? Or does anybody know if I can link controllers together?

You can build one from Regulators, but they tend to have a large drop out voltage. You can do it with transistors, they have less of a voltage drop. I would reccomend PWM, but I dont know of any chips that can do that (besides the 555 timer of course)

transistors-http://www.cpemma.co.uk/ef.html
Regulators- http://www.cpemma.co.uk/reg.html

If you need any help along the way with building it, I'll be happy to help

You dont want a Reostat btw, at thats amperage it would cost you errr...alot of money (I'll say 30 bucks.. or so as an estimate..)

EDIT- I am actually thi9nking of building the transistor one for myself. Total Cost is around 10 bucks (well, thats because I have the transistors, and Im going to make the knobs..hint hint hint)

Best Source of parts- http://www.bgmicro.com

I have a 6 Amp aspire controller,bought it at directron ,but last time I looked they were sold out .
I'll look and post a link If I find some.

If worse came to worse you could use those dimmers that you use to dim lights in your house. Im pretty sure they could handle 3 amps... With a little modding anything is possible.