Hum Free Electronic Fan Regulator

[atif_butt82]

Hi. i m tryin to design a hum free electronic fan regulator but so far i m unable to do so.. the prob. i m facing right now is i m unable to control the cycles/hz at 50 cycles/hz at all speeds. can any body help me abt that?

 

[nc5p]

Look into this:
http://www.microchip.com/stellent/idcplg?IdcService=SS_GET_PAGE&nodeId=1406&dDocName=en531591

I built a three-phase drive using the dspic controllers. They are pretty easy to get up and running. Use the highest frequency you can for the pulse width modulation. That will get rid of the hum. You can still get as low a drive frequency as you need.