On Fri, 3 Aug 2001, Roman Black wrote:

> Have you considered a relay? A "real" relay that
> is! :o) Simple to drive with your PIC and should
> work your AC fan load ok since you say it is low
> power.
> -Roman

  Roman, Nick, what do you say about this:

One npn transistor driven in base through a resistence from pic,
transistor will short circuit ( when is on ) the +/- section of one
rectifying bridge, colector to +bridge pin, emiter to -bridge pin and
GND of pic supply. In series with ~ bridge pin, the fan , the other fan
pin and ~ pin of the bridge to AC.
( same configuration like those used for driving full AC load using
thyristors but with transistors )
I think will work ok and will be better than a relay.
Vasile

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