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PostPosted: Thu Aug 22, 2013 7:53 am
by freeman401
Hello from Russia!
9V battery is only to compare sizes
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My drsstc doesn't have any things from OneTesla, but I decided to post it here because of it's size. It's like OneTesla, but smaller.

This is a halfbridge of IRGP50B60PD1 (I highly recommend them for everyone! they are nearly-indestructable, they can work at 350Apk on frequency up to 400kHz without predicter), modified driver from Steve's DRSSTC-3 (double UCC is replaced with ucc27424 and complementary mosfets irf7379, added UVLO).

Secondary is 19x8cm (7.5x3.15 inches), wound with 0.17mm(35awg) wire, with 18x5cm (7x2.5inches) toroid it has res. freq. about 230kHz

Max. recorded spark is 25" long! It can produce 15-18" sparks continuously.

(There's 23")

secondary is grounded to AC line through 0.68uf film caps
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PCB is crap, soldering is crap, but it works perfectly
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And, yeah, I've made it when I was 14 years old :mrgreen:

Re: 7.5" DRSSTC

PostPosted: Thu Aug 22, 2013 10:59 am
by Bayley
Hmm, the IRGP50B60PD1 should be a drop-in replacement for the 60N65's we use - have you tested them to destruction? We've confirmed that the 60N65 fail at a bit over 350A (which is why we run a bit under 300A with the default pulsewidths).
Have you tried music? Curious as to how the IR IGBT's hold up under higher duty cycles.

Re: 7.5" DRSSTC

PostPosted: Thu Aug 22, 2013 11:34 am
by freeman401
Experiments of my friend shown that with OCD set to 400A in 150-200kHz full bridge drsstc these igbt's doesn't blow up.
I've tried to play music with max. BPS ~700. Igbt's were warm on 300cm^2 heatsink with fan after 50 seconds.

Re: 7.5" DRSSTC

PostPosted: Thu Aug 22, 2013 12:13 pm
by Bayley
Interesting, so the IR "warp speed" IGBT's are good for way more peak current but are lossier overall, it appears.
What kind of wall current were you drawing at 700BPS?

Re: 7.5" DRSSTC

PostPosted: Thu Aug 22, 2013 12:38 pm
by freeman401
If I correctly understood your question, then answer is
I've measured ~300Apk on 300BPS with 20" streamer.
I think that with good heatsink and thermal pads these igbt's can hold up 300-350A at 700-1000bps

My friend made this extremely effective heatsink base for igbts:
He soldered them directly to BaO ceramic pads and then to silver plate...
This halfbridge handed up 250-280A at 1700bps for about two minutes(if I'm correct), then it blown up