Richterkessing, Frank H (GEA, 055132 ) wrote:
  >
  > Peter,
  >
  > Very clever idea. I follow your circuit description up to the point
  > about the 22k resistor. Mains hot to???? Also, do the capacitors
  > need to be anything special?
  >
  > Thanks,
  >
  > Frank Richterkessing
  > Experimental Methods Engineer
  > GE Appliances
  >
  > FRANK.RICHTERKESSING@APPL.GE.COM
  >
  > >----------
  > >From:  peter cousens[SMTP:peter@cousens.her.forthnet.gr]
  > >Sent:  Monday, December 09, 1996 9:42PM
  > >To:    Multiple recipients of list PICLIST
  > >Subject:       Re: Dumb question on Application Note 521
  > >
  > >The original application for the thread was to control
  > >AC mains lights
  > >There is another way to control AC mains that does
  > >involve zero crossing
  > >It does require a few more components but the results
  > >are superb
  > >It's suitable for lights, motor control and many other AC
  > >mains apps
  > >
  > >The components that follow are for 220V
  > >
  > >You run the AC through your load, in series with a bridge
rectifier.
  > >The +/- you connect to a cap (1 or 2 microFarad 400V, parallel up
 some
  > >.47's )
  > >in parallel with a transistor (eg. TIPL 760 )with a 220 Ohms 50W
  -----------------------------------------------------------------
  SORRY the 220 resistors in series with the caps not the TIPL 760
  And the caps should be 400v  polyester film or layer
  -----------------------------------------------------------------
  > >(depends
  > >on the power you want to draw) in series (in the collector)
  > >to limit the current to a safe level.
  > >A MPSA 42 to drive it, a BC 549 to drive the MPSA, which is driven
 buy
  > >an opto
  > >Power for the "hot side" is taken from the mains via a 22k 1 watt
  > >resistor
  ----------------------------------------------------------------
  THE HOT SIDE OF THE CIRCUIT IS THE PART THATS NOT ISOLATED ie:
  The tipl 760,mpsa 42,bc 549,everything upto the opto,
  ----------------------------------------------------------------
  > >
  > >The opto is driven non from syncronised PWM direct from the Pic.
  > >The TIPL 760 works in switch mode and shorts out the bridge via the
 220
  > >Ohms
  > >resistor the entire circuit is very efficent
  > >and should handle at least 100 Watts probabaly more
  > >
 I am including a circuit,its in windows paintbrush format
  --
  Peter Cousens
  email: peter@cousens.her.forthnet.gr
  snailmail: Peter Cousens, karteros, Heraklion, Crete, 75100, Greece,
  phone: + 3081 380534,    +3081 324450   voice/fax

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