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[Roger Heflin]

On Mon, 1 Feb 1999, Shannen Durphey wrote:

> Tom Sharpe wrote:
> > 
> 
> > 
> > How do you PWM a 15 amp load??? Someone design a circuit please. Can the driver
> > board be mase to work??
> > 
> > TIA  TOM
> That's a good question.  How do they PWM the coolant fans? I know I
> can hear the relay clicking away..
> Shannen

My guess would be that you would need at least two stages, first a
small transistor to provide enougn current to drive the actual power
transistor.  I don't know what you would need for a power transistor.
I think the 2N3055 maxs out a 15 amps in a TO-3 case with a heat sink,
so you might need to look for something slightly bigger, and you would
probably have to watch the PWM on/off cycle to make sure the on/off
steps are not too fast for the power transistor.

			Roger