[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
hvguy-dot-com flyback driver - NEW SCHEM.
Original poster: "Justin Hays by way of Terry Fritz <twftesla-at-qwest-dot-net>" <pyrotrons2000-at-yahoo-dot-com>
(the stuff in question is at www.hvguy-dot-com, at the very top, the four
flyback arc pictures!)
Last night I designed and built a suitable signal generator for the
new flyback driver. At first glance the circuit is a little complex,
but for what it does I think it's worth it. I'm using the circuit for
a laser power supply, and I need the variable output voltage and
current this circuit will provide. The spec's of the generator are:
5kHz to 200kHz Freq. adjust. (will tune most if not all flybacks)
0 - 100% duty cycle adjust.
Each adjustment is completely independent of the other.
Extremely clean square wave output, suitable for MOSFET gate drive.
R4 is the FREQUENCY ADJUST pot
R12 is the DUTY CYCLE ADJUST pot
To change output voltage of flyback, adjust R4 for resonance. There
will be a strong voltage peak at resonance. Go above or below the
resonant frequency for less voltage. I am going to set my pot's
accordingly, so that in effect I turn up the output voltage instead
of tuning a flyback ; ) Hopefully I can make resonance hit right at
the end of a right-hand turn of the pot.
To change the output current, adjust duty cycle with R12. The more
duty cycle, the more output current, up to a certain point of course.
Above that point the circuit will just eat input current and run
inefficiently. That point is about 65% using a driver I tried a long
time ago. It would probably be wise to set a max duty cycle of 70% or
so. DO NOT go above 80%, you will most likely lose your MOSFET and/or
MUCH more info coming on these circuits, it will all be posted there
and not here to keep our moderator happy. I don't want to post every
single update, this is the last one unless something big happens. So
check in occasionally if you wish!
www.hvguy-dot-com, at the very top, the four flyback arc pictures.
Thank you Chip and Terry for a great list,