Re: (ET) pwm

["Ken Muldrew" <kmuldrew ucalgary ca>]

On 15 Jun 2005 at 16:53, neil wrote:

> Just did a "google" on "pulse width modulator", all kinds of hits.  Many
> years ago, my son and I built a model railroad speed control using a PWN
> circuit, at that time we had to use discrete components, now I think 
> there
> are IC's to do the timing, I'd use power FETS for the switches (I think),
> rather than transistors.

For a simple circuit (the hard stuff is buried in the HIP4081 chip), try 
the OSMC (open source motor controller) project at:

http://www.robot-power.com/downloads/

Ken Muldrew.