Re: Please help ! IGBT exploded ...

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

Original poster: "Robert Jones" <alwynj48-at-earthlink-dot-net> 

Hi Steve,

Comments in text,
----- Original Message -----
From: "Tesla list" <tesla-at-pupman-dot-com>
To: <tesla-at-pupman-dot-com>
Sent: Tuesday, March 09, 2004 6:16 AM
Subject: RE: Please help ! IGBT exploded ...


 > Original poster: "Steve Conner" <steve.conner-at-optosci-dot-com>
 >
 >
 > To get the deadtime to work you must drive your GDT primary with a
 > full-bridge of two gate driver chips, each fed from one output of the
TL494.
 > This allows the driver chips to short the GDT primary during the deadtime
 > periods, forcing the voltage to zero and turning both IGBTs off.

My understanding was one method of driving the IGBTs is  with a +/- signal
to turn them on and off.
To get the dead time you have all the IGBTs off and have separate drives for
each side of the H bridge.

Is the technique your suggesting one GDT with a three state drive ie +,0,-
which correspond to: one side on, all off, other side on respectively.
Presumably the disadvantage is that the IGBT are turned off with a 0v gates
signal as opposed to a negative signal. Is this correct?

Bob