Re: Cooling MOFSETS and IGBT's.

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

Original poster: "Metlicka Marc by way of Terry Fritz <twftesla-at-uswest-dot-net>" <mystuffs-at-orwell-dot-net>

yes but at the currents we can expect, and hope, to use, won't we be
seeing a somewhat different effect? then to i remember reading something
about the ac resistance's at higher frequencies. at current there would
have to be some substantial heating, otherwise i wouldn't see as many
water cooled SCR bridges?

Tesla list wrote:
> 
> Original poster: "Richard Wayne Wall by way of Terry Fritz
<twftesla-at-uswest-dot-net>" <rwall-at-ix-dot-netcom-dot-com>
> 
> Terry,
> 
> Excellent point.  No energy is dissipated by the IGBT while in the off state
> and very little while in the full on state since it has a very low Ron.  Heat
> is dissipated primarily during switching from off-on and on-off.  Resistive
> losses occur primarily during these transitions.  So very high dI/dT and fast
> turn on/off states are very desirable.
> 
> RWW
> 
> >
> > However....  I would hope a SSgap would not require anything but modest air
> > heat sinks.  If I go pumping hundreds of watts into heating the water, that
> > energy is coming directly out of the streamers energy...  I think the trick
> > is to keep the power dissipated in a solid state gap as low as possible so
> > the streamer gets all the power.
> >
> > Cheers,
> >
> > Terry
> >
> >
> >
> >
> >