> -----Original Message-----
> From: Tony Nixon [SMTP:tony.nixon@ENG.MONASH.EDU.AU]
> Sent: Friday, August 30, 2002 12:52 AM
> To:   PICLIST@MITVMA.MIT.EDU
> Subject:      [PIC]: Propellor Clock
>
> Hi all,
>
> Well I got my wings presented to me the other night :-)
>
>
> They were supposed to raffle the propellor clock I donated for the
> runway sealing fund raiser, but due to other raffles, it was decided
> that it was a bit too much to expect from everyone, so it will be
> raffled another time.
>
> It sure made a few eyes pop out and I'm sure the raffle will go off
> well. I've already been asked to make more and the president of the
> club, who is also a QANTAS captain, wants two. I knew this would happen,
> and I'm not sure I can put a price on something that took that long to
> make.
>
> Anyway, the tinkerer that I am, I have designed a simpler way (yet to be
> tested) and I told them I "would see".
>
> As part of my circuit, I used a relay to convert a full wave rectified
> AC input to a half wave to detect when the "time set" switch is pressed.
> This is just a series diode being switched in and out of a leg of the AC
> path to the full wave rectifier.
>
> Is there a way to do this without a relay?
>
If you use four individual rectifiers instead of a full bridge, you could
use a MOSFET to switch one  of the the rectifiers on the negative side to
ground.

Regards

Mike

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