RE: OLTC - Inside the PWRX CM600HA-24H

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

Original poster: "Adam Horden" <ath-at-blueyonder.co.uk> 

Terry,

I got 10 of these bricks from CT something surplus on ebay for like $30

They all have X on them. Two tested fine and shipped them out to a
seller today.

What does this X mean?

Adam

-----Original Message-----
From: Tesla list [mailto:tesla-at-pupman-dot-com]
Sent: 15 April 2004 05:11
To: tesla-at-pupman-dot-com
Subject: OLTC - Inside the PWRX CM600HA-24H

Original poster: Terry Fritz <teslalist-at-twfpowerelectronics-dot-com>

Hi All,

I got a batch of those 600 amp 1200V PowerX CM600HA-24H IGBTs that Steve
C.
uses on his wonderful OLTC.  Mine were a little more "used" since a few
had
red tech grease pencil "X"'s one them...  Hey!  I know what that means
:D  They did the preventive maintenance of replacing the IGBTs a few
milliseconds too late...

No problem since I got them at 1% the retail price ;-))

It read "gate ****** up" on the meter.  So I pulled the screws and
applied
a "spread spectrum force instrument" to the case (hammer).  I then
chopped
the buss bars and dug through the "gorilla snot" as is typical for those

familiar with the high art of de-kitting large brick power devices...
So,
as if Hot-streamer was not bogged down tonight with all 1500 of you
downloading the cap x-ray pics :o))), here is what is inside:

http://hot-streamer-dot-com/temp/CM600HA-24H.jpg

Just eight big ~ 20mm IGBT die in parallel and the eight reverse diodes
on
a aluminum nitride substrate.  The gates on two have been over voltage
and
fried two chips.  Probably another device incinerated and the buss
voltage
got onto the gate buss.

Sort of neat.  Be sure not the flex the copper bottom too much ;-))

Cheers,

	Terry