RE: drsstc - catastrophic failure! And Thor

["Tesla list" <tesla-at-pupman-dot-com>]

Original poster: "Stephen Conner by way of Terry Fritz <teslalist-at-qwest-dot-net>" <steve-at-scopeboy-dot-com>

At 07:59 29/04/03 -0600, you wrote:
>Original poster: "by way of Terry Fritz <teslalist-at-qwest-dot-net>" 
><Marco.Denicolai-at-tellabs-dot-com>
>
>Moral: this is IMHO a compromise. I haven't got strong evidence that
>this solution actually saved any IGBT but some evidence I have got that
>it doesn't kill them. The truth is that it is still a kind of mistery
>what was the mechanism that resulted in the IGBT pair shorting Vcc to
>GND and, thus, committing suicide. I believe it really was the IR2112
>going into latchup and forcing both IGBTs into on state. Limiting the
>spikes around it prevented the latchup.

I misunderstood what the protection circuit was for. I forgot that you 
didn't need current limiting as such because the resonant circuit limits 
the current by design. In that case I suppose I would leave it out 
altogether. If the driver chip latches up, it's probably gonna be fatal :-at-


>At today, Thor rev. B has performed 6 shows (the last one yesterday
>night) and no failure yet. This sets a record, even if it surely makes
>many of you readers smile or even laught... :)

6 shows is more than any of my coils has managed yet.


>I have almost got ready the new Controller board that allows me to make
>a predetermined number of bangs (from 1 to 4080)

That sounds like a great tool for studying streamer growth... What were you 
planning to use it for?

Steve C.