[TCML] New SISG failure mode

[bartb]

Hi Phil,

Better check that Mouser inventory. I purchased over 80 myself back when 
we were discussing it. ;-)

Have you found any heating of the Sidac's since our last discussion? I 
decided to leave them "unsunk" but staggered the Sidac fins for more air 
gap between them. My 6 board SISG is finished and I've been working 
diligently on the base cabinet. Hopefully, I can get the coil finished 
this weekend and give it a Pole Pig test (and see if those cheaper 
IGBT's will work for us).
Take care and thanks for the update,
Bart

FIFTYGUY at aol.com wrote:
> Folks-
>  
>     I was going over the rest of my SISG to see how  many replacement SIDACs 
> to order *this* time (note to self: buy stock in  Littlefuse). Previously 
> damaged sections either had both the IGBT and all the  SIDACs blown, or recently 
> just the SIDACs. So I had figured it was the SIDACs  dying first that took out 
> their IGBT.
>     But this time I found a damaged section  that had good SIDACs, but a 
> blown IGBT! Even more significantly, the  gate was still at a high resistance to 
> the body, and I observed its  capacitance charging up from the digital 
> multimeter. But the emitter and  collector were dead shorted! 
>     My guess is that this IGBT suffered from secondary  breakdown. Does that 
> make it an IGSS now? (Insulated Gate Silicon Shunt).  All other components in 
> that module appeared and measured perfectly fine,  including the TVS's. Could 
> this be the result of excessive pulsed current or  overheating?
>  
>     (Note to self: buy stock in International  Rectifier...)
>  
> -Phil LaBudde
> Center for the Advanced Study of Ballistic  Improbabilities
>
>
>
> **************Vote for your city's best dining and nightlife. City's Best 
> 2008.      (http://citysbest.aol.com?ncid=aolacg00050000000102)
> _______________________________________________
> Tesla mailing list
> Tesla at www.pupman.com
> http://www.pupman.com/mailman/listinfo/tesla
>
>