Re: OLTC update

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

Original poster: "Jan Wagner by way of Terry Fritz <twftesla-at-qwest-dot-net>" <jwagner-at-cc.hut.fi>

> > 4.  Decrease gate drive resistance to 10 ohms.
>
> Ah, ok, you were using 82 Ohms?
>  http://hot-streamer-dot-com/temp/OLTC-IGBTdrive.gif
>
> Miller causes
>   I_cg = 2*pi*100kHz * 50pF * 480Vpp = 15mA
> just as a guesstimate, for each igbt.

Oops, my apologies! I just forgot the parallel diode in the IGBT, and
then the collector-emitter voltage of course never will be 480Vpp during
igbt ON state. So please ignore. ;)

But less gate resistance should nevertheless help to get a better signal
and less noise on the gate. With all the HV RF around...

cheers,
 - Jan

--
*************************************************
 high voltage at http://www.hut.fi/~jwagner/tesla
 Jan OH2GHR