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Re: interesting new IGBT



Subject:  Re: interesting new IGBT
  Date:   09 May 97 11:24:39 EDT
  From:   Alan Sharp <100624.504-at-CompuServe.COM>
    To:   "INTERNET:tesla-at-pupman-dot-com" <tesla-at-pupman-dot-com>


Greetings William, all

Thanks for the info but at the moment unless someone knows
better the irf740 mosfet has it for price &  performance.
(apart from spark gaps that is)

400v, 10A continuos, 40A peak, 125W switching times
around 25ns. It would be nice if a single pair would handle
8000W but alas heat disappation and switching losses lower this
to say 200W max from each device. 

The other problem is that to get 600v or 300v you'ld need a
transformer (- this is not a common value.) Full rectified mains
gives 370v DC - fine for a irf740 half bridge. 110v AC transformer
gives 160v DC - fine for a 740 pushpull. Remember you get
double the supply voltage on the unused leg of a push pull
1200v, 600v device - ZAP :) 

100kHz is OK for a fat squat coil. Lower frequencies reduce
switching losses but need bigger output transformers.

Nice sparks at 8,4KW yes but a lot of ex semiconductors.

Have fun,

Alan Sharp (UK)

>I'm not into transitor coils (at least not yet), but I noticed an
>announcement 
>from Harris corp for the HGTP7N60N3 family - they say they are rated at
7amps 
>600 volts with losses in the 50 to 100 Khz range that are "competitive
with or 
>lower than more expensive mosfets".  IT would seem to me that a pair of
>these 
>babies in a push/pull configuration could put some pretty good primary
>energy 
>- let's see, 1200 volts (peak) at 7 amps is 8.4 peak KW,  that ought to
>be 
>enough to create some nice sparks, although if I read the list right,
>the 
>100Khz listed may be a bit low compared to the 300Khz most of the 
>measured 
>coils seem to run at.

>anyway, harris is at www.semi.harris-dot-com i