Updated OHVM Upload

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Original poster: "David Sharpe by way of Terry Fritz <teslalist-at-qwest-dot-net>" <sccr4us-at-erols-dot-com>

All

Updated status of OHVM project at this point.  The filename is
OHVM-II-upload.xls at

  http://www.hot-streamer-dot-com/dave/

Block Diagram and schematics are current (3/19/03),
board layouts may have differences.  I've got to install
2.8K 1% load resistors on divider PCB, and mount
BNC cables. Signal conditioning board is current but
does not include precision rectifier.  I promised info on
a potentially new SSTC driver and I have provided.

In tab "Sch05-PWR_IsoPWR" in spreadsheet is schematic
of iso power driver using Unitrode UCC3808A-2
current mode push-pull PWM IC.  Is tunable to 1MHz,
and is blantantly running open loop.  In tabs
"UCC3808A-2 PCB and UCC3808A-2 PCB Assembly"
is PCB layout and assembly for driver minus GDT.
Chip is capable of driving up to 0.5A directly, and with
extended runs at 200Khz running +/-12V -at- 50mA supplied
to load, there was very minor heating detectable on chip.
PCB can be directly laser jeted to "Iron and Peel"; plot
at 24% for 1:1 reproduction.  This little "daughter board"
has been assembled, layout is correct and is fully functional
as an open loop variable frequency driver.  To gate
"staccato" mode the chip, FB pin would be modulated,
check data sheets on chip for specifics.  CS (current sense)
is an internal fault and will force a soft-start restart.  NOTE:
maximum input supply voltage to IC is 15V.

Signal conditioning board is being redesigned to allow
assembly in a aluminum enclosure and include precision
rectifier; so this info is pretty much status quo.  Hope
this info is of interest...

Best Regards
Dave Sharpe, TCBOR
Chesterfield, VA. USA