Re: IGBT gate drive experiences-Reply II

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

Original poster: "David Sharpe by way of Terry Fritz <teslalist-at-qwest-dot-net>" <sccr4us-at-erols-dot-com>

Hi Marco

Tesla list wrote:

 > Original poster: "by way of Terry Fritz <teslalist-at-qwest-dot-net>" 
<Marco.Denicolai-at-tellabs-dot-com>
 >
 > Hi David,
 >
 >  > -----Original Message-----
 >  > From: tesla-at-pupman-dot-com [mailto:tesla-at-pupman-dot-com]
 >  > Sent: 2. tammikuuta 2003 01:11
 >  > To: tesla-at-pupman-dot-com
 >  > Subject: Re: IGBT gate drive experiences-Reply II
 >  >
 >  >
 >  > Original poster: "David Sharpe by way of Terry Fritz
 >  > <teslalist-at-qwest-dot-net>" <sccr4us-at-erols-dot-com>
 >  >
 >  > Hi Marco
 >  >
 >  > Another comment concerning CCPS Rev. B ...
 >
 > I didn't get your first comment (Reply I ?).
 >

I tried to download the schematic, your server wouldn't give it to
me, but Terry already had it on hotstreamer (Thanks!)  :^)

 >
 > If it's still breaking, I'll get back to this issue with you. Thank you.
 >

About 12 years ago, I built a magnetic clutch drive that was basically
a half bridge driver to +/- 24VDC to alternate polarity each time
operated to try to eliminate residual magnetism and increase
response speed.  Was using Powerex 20A, 450V totem pole
darlington transistor module (robust, eh?).  WRONG, blew up ten
(10) within first week of putting in service, and this was with a 30V
transorb and (100ohm + 100nF) R+C snubber across solenoid coil.
Added a 10nF PP film across each CE of driver and problems vanished!
Realize, this was a very SLOW speed operation as well (10 operations
per minute or less).  OBTW, transistors had copack high speed
anti-parallel diodes.  Transistors were reverse avalanching with
turnoff transisent in the 100ns regime, the weak ones died, the good
ones would work... for awhile.   :^C

 >  > The other
 >  > point is the
 >  > loop area between your filter capacitor and the IGBT totem
 >  > pole must be
 >  > as small as possible, the loop area and induced currents can generate
 >  > horrible ringups.
 >
 > The loop area is as small as I could design it. Would you have a look to
 > the PCB and tell me what you think about it?

I'll go to your website tonight and look at the PCB layout.

 >  > This circuitry is nearly identical to IR21531D half bridge
 >  > circuit I'm building
 >  > for a SSTC / IH driver so that's why your work is of much
 >  > interest at this end.
 >
 > Please, let me know about how that will perform.
 >

When we get something operating will let you a list know...

 >
 > Best Regards
 >

Best Regards
Dave Sharpe, TCBOR
Chesterfield, VA. USA