Re: Solid-state status

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

Original poster: "Roderick Maxwell by way of Terry Fritz <twftesla-at-uswest-dot-net>" <maxz-at-netdoor-dot-com>


----- Original Message -----
From: "Tesla list" <tesla-at-pupman-dot-com>
To: <tesla-at-pupman-dot-com>
Sent: Saturday, December 16, 2000 11:03 PM
Subject: Solid-state status


> Original poster: "Kennan C Herrick by way of Terry Fritz
<twftesla-at-uswest-dot-net>" <kcha1-at-juno-dot-com>
>
> Holiday madness being upon us, my T.c. work has slowed.  But some may
> have interest in the current problem:  Turns out my gate-drive lines are
> too long.  Some ringing but the more serious problem is Miller current at
> MOSFET turn-off, causing turning on again of those that are supposed to
> be going off, by virtue of the voltage drop in the too-long lines.  Such
> turn-on is a major no-no, of course, so I am having to re-do my
> gate-driving scheme.

  Have you tried using some 2 watt 10 ohm carbon resistors close to the
gates?
They will dampen any ringing at the gate at the expense of slightly slower
switching times.


  It will take some semi-major scrambling-around of
> circuits, cutting of p.c.-board traces, adding jumpers, etc.  Dog-work,
> like much of the previous toil leading up to the present design.
>
> But basically, my "current-loop" scheme works and--as soon as we clear
> this season's frenetic activities, I'll get to that dog work & advise.
> No offense to dogs.
>