[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
Re: SISG Testing/Waveforms
Original poster: Vardan <vardan01@xxxxxxxxxxxxxxxxxxxxxxx>
Your getting very good second notch quenching :-)))))
It might be possible to do first notch too. I modified my
experimental SISG boards for a R4 pot and (big) 1/4 inch aluminum
plate heat sinks:
I can cut the plate aluminum with the band saw and mill it easily
enough for perfect custom sinks. The next coil also has "big" fan
;-)) Not sure if I'll make a clamp like you or just continue to use
the thermal epoxy... Not too hard just to "mill off" a blown
IGBT. But they don't seem to "blow" anyway ;-)))
I am thinking, with some fiddling, one might be able to dial in the
first notch. MicroSim disagrees with me, but maybe I can go for
second notch at least. It might be much easier at a lower Fo
frequency. My next coil is about 134kHz...
At 07:18 AM 7/20/2006, you wrote:
All SISG followers:
Finally got the scope back.
Recall that I was previously getting 1000 BPS with the SISG.
Subsequently, I had managed to increase the transformer(4 MOTs)
impedence(primary side) from ~1.7 ohms to ~8 ohms by re-shunting. In
addition, I doubled the tank capacitance from 38 to 76 nF. Both had a
significant effect judged by sound and performance.
The new waveforms are shown here:
Now getting 120 BPS which means I am firing near each charging peak.
Using (4) SISG boards or (12) circuits for a threshold 10.8 kV.
Using 680 ohm IGBT timing resistor to get the IGBT "on" time down.
Input VA ~1500
Transformer VA ~1200
Power ~800 watts
Haven't had time to re-tune accurately, but coil runs great anyway.
Need to install a vent fan for the ozone in the basement.