Aaron J. Miller wrote:
>
> Hello all,
>
> This question is only marginally related to pic's since I am going to use
> a 16C84 to control the chopper, but there seem to be quite a few bright
> people out there who may be able to help...
>
> I am trying to make an incandescent lamp dimmer from a 16C84 and planned
> on doing a simple waveform chop using a triac.  I realized, however, that
> since the pic is going to be doing a bunch of other time sensitive stuff
> that I don't have the processor time to manually sense the zero and chop
> the wave using the pic.
>
> So, is there any easy method to passively (from the pic's point of view)
> chop the AC wave?  i.e. use 8 I/O pins to a D-A to give a reference to the
> chopper circuit and have it do the rest?  That way I can just output the
> light level to the pins and it would stay put leaving the rest of the
> processor available?
>
> Thanks for any help,
> aaron
>
>
 -------------------------------------------------------------------------------
> -     Aaron J. Miller           Email: millera@stanford.edu
> -     Physics Graduate Student  Web  : http://www.stanford.edu/~millera
> -     Stanford University       Phone: (415) 372-5575 (until 4/12/97)
>
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Not exactly an ac chopper but it controls AC loads very well

Take a look at this circuit it's opto Isolated and you drive the
opto led with PWM at whatever frequence you program allows
(within reason, 50Hz to 10KHz)
It requires no synchronisation so only one PIC pin is needed

It's in bmp format

If you have any questions email me direct if you like

Peter Cousens
peter@cousens.her.forthnet.gr

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