[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

SSTC updates



Original poster: "by way of Terry Fritz <twftesla-at-qwest-dot-net>" <Fucian-at-aol-dot-com>

Hi, i thought I would mention some things about my sstc and sk a few more Qs.

Im using just a single mosfet pulsed by a pair of 555s.One is pulsing the 
second one.I have a Q.I really didnt know where to plug the Staccato 555 
output to on the second 555.I stuck it in pin 5 because it gave much better 
output.Where should it have gone?Oh well, im getting better output.

To stop high voltage spikes( at least its supposed to) i have a 1500W TVS 
diode going cathode to drain of the MOSFET and anode to the source of the 
MOSFET.Is this wrong?(I dunno)I also have a .047 capacitor across the drain 
and source of the MOSFET.I read online that it should stop spikes?Wouldnt it 
just cause ringing?(oh well its in and doesnt seem to be trouble.)

I am getting about 2.5-3in sparks at 40vdc in.(140V 4.5amp variac with bridge 
rectifier and capacitor)

I want to pump it up to full power but im afraid.The MOSFET usually fails at 
around 90 volts.Sometimes its burning hot, sometimes not.Its getting a little 
warm now at 40volts.I guess if it was going to get an overvolt spike, it 
would have done so now?

Oh yea, ive got an antenna REAL close to the secondary and it goes directly 
into pin 2 of the 555 that pulses the primary.(3 turn 12awg primry).The coil 
wont work without this antenna.

VERY GOOD plasma display with lightbulbs.No streamers unless i bring 
something close and then they pop out.WHY?

Anything I should change?(Besides circuit?)Is my output(close to 3in) good 
for 40volts in?

Matt