Re: BIG solid state devices...

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

Original poster: "Sean Taylor by way of Terry Fritz <twftesla-at-qwest-dot-net>" <taylorss-at-rose-hulman.edu>

> Hi,
>
> I note the Hitachi MBN1200D33C
>
> http://www.hitachi.co.jp/Div/ise/pdevice/igbt/index-e.htm
>
> http://www.hitachi.co.jp/Div/ise/pdevice/igbt/d-igbt/1200d33c.pdf
>
> switches 3300 volts at 1500 amps with 6 volts of CE drop...  If one were
to
> put 8 in series to run a 21kV firing voltage, you would get about 48 volts
> drop or 48 x 21000 = 1008000 watts (i) of instantaneous power loss.  But
> the system power is 1500 x 21000 = 31500000 watts (i)

I'm confused . . . Why did you multiply the voltage drop by the firing
voltage?  Power lost should be 48 x 1500, so 72000 watts, while the total
power is 31500000 watts, so about 99.8 % efficient.

Sean