[SOLVED] ac motor speed controller

If the speed regulator and the fan are connected by two wires, it is basically a voltage controlled device and your triac controller is expected to work.

Well, I believe I have a good conclusion to this issue. I am using voltage control. I took an old computer power supply box and removed the guts except for the little cooling fan. I then put in an autotransformer (from a broken stereo amplifier) which had a 65v and a 15v tap. I installed a wall receptacle and attached it to the 65v tap. At the 15v tap I built a small rectifier with voltage control to run the cooling fan. I needed the cooling fan because the autotransformer got plenty warm. So now I put 120v into the autotransformer and plug my Lasko fan into the 65v receptacle and presto... quiet air blowing. Having said that I will add that I had also tried a cheap filament bulb triac dimmer. That also seemed to work OK, except that there was a little hum-like noise at slow speed. So I prefer the low voltage solution. Thanks for all your help

I'm glad that you found a solution that works for you.

Indeed the dimmers will create some noise at low voltage settings, because of the narrow trigger angle.

I wonder if the low voltage high current noise is from magnetostiction in the ferrite and if a Motor Run cap,would reduce the noise across transformer output. It would certainly reduce current ripple.