[Laser] Success modifying Coleman inverter for modulating HPS/fluorescent

[Kerry Banke]

Over the weekend I was successful at modifying my Coleman 400W 12VDC 
to 120VAC inverter to modulate HPS and flourescent lamps. I use a 
CMOS op-amp to square up the 135 Hz center frequency Jason Software ( 
4Hz BW)  audio drive from my Laptop or MP3 player , divide it by two 
( the lamp modulation is second harmonic) and use it as the reference 
input to a 74HC4046 PLL chip.  The other input to the phase 
detector  is the inverter AC  output limited to CMOS logic levels. 
The output of the phase detector drives the VCO section with a 
nominal center frequency of 9 MHz which is injected in to the 
inverter control chip in place of the stock 8 MHz (at 60 Hz ) 
crystal. I'll finish cleaning up the schematic and will make it 
available to anyone     requesting it.  The next step is to get 
the  HPS optical beacon ready to install for  tests on a mountain top 
via remote control.
  - Kerry N6IZW  -