Re: Shottky Diodes in SSTC ---> Not A Necessity

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

Original poster: "by way of Terry Fritz <teslalist-at-qwest-dot-net>" <dhmccauley-at-spacecatlighting-dot-com>

 > You're not going to believe this, but I can *almost* say that
 > back-to-back zeners from gate to source are unecessary too. This is
 > pushing it, I know, but I can't ignore my own findings. I have gotten
 > 16" arcs without any zeners in a IRFP460 full bridge. The gate
 > signals were still very clean with no Vspikes past + and - 20V. I
 > did, however, use a very powerful driver I designed that has an
 > output impedance of less than 100 milliohms.

Well, I completely disagree with this statement especially when using high
priced FETs such as the IXFN24N100s which I use for my SSTCs which cost over
$50.00 each.
Protection devices such as these (transient voltage suppressors) are
especially required in SSTCs where there is high noise, kickbacks, etc... On
my SSTCs i get transient
voltage spikes over 100Volts on my FET gates with no protection devices.

Remember, just because you don't see an immediate need for them, that they
are unecessary.  Its the scenario you can't think of that can really ruin
your day.  I'd rather
blow out some zener diodes and my FET drivers any day of the week rather
than blowing my IXFN24N100s ! ! ! !

The Captain





 > Anyhow...SSTC's are cool!
 >
 > Take care,
 >
 > Justin Hays
 > KC5PNP
 > Email: justin-at-hvguy-dot-com
 > Website: www.hvguy-dot-com
 >
 >
 >
 >
 >