BTW, Eben, do you have code for the 628 & this circuit to share?
I would love to play along.....I have done this for SCR pairs with an 18C442
in asm, and it was way too much work. AC power control is sort of a hobby
for me....

CL
  -----Original Message-----
  From: pic microcontroller discussion list
[mailto:PICLIST@MITVMA.MIT.EDU]On Behalf Of Eben Olson
  Sent: Friday, December 14, 2001 8:25 PM
  To: PICLIST@MITVMA.MIT.EDU
  Subject: [EE] question about light dimmer circuit


  Hi all. I'm trying to build some PIC-controlled light dimmers for my
school theater. After looking at some schematics from the internet, I pieced
together the attached basic diagram. But if anyone has experience with this
kind of thing, I have a few questions. I'm very confused about how to
calculate the wattages required for the resistors. Using V=IR, and P=VI, it
seems like the 1k resistor between AC supply and the MOC triac trigger would
have to take about 15 watts. Is this correct?
  TIA,
      Eben Olson

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