From: "Tesla list" <tesla@xxxxxxxxxx>
To: tesla@xxxxxxxxxx
Subject: Re: coil running of car battery(s)?
Date: Tue, 25 Jan 2005 08:11:33 -0700
Original poster: "Bob (R.A.) Jones" <a1accounting@xxxxxxxxxxxxx>
Hi Derek,
Well unless they have some protection or they have come up with a new gate
material yep that's a quick way of killing them one very narrow spike will
do it on the gate.
The older power fets did not even like a spike on the output. I assume this
one avalanches in a controlled fashion just soaking up the joules over the
whole die. Still 1/2J is impressive assuming I did not miss read the spec.
Robert
----- Original Message -----
From: "Tesla list" <tesla@xxxxxxxxxx>
To: <tesla@xxxxxxxxxx>
Sent: Monday, January 24, 2005 4:21 PM
Subject: RE: coil running of car battery(s)?
> Original poster: "Derek Woodroffe" <tesla@xxxxxxxxxxxxxxx>
>
> >Hi Derek,
>
> >I was curious about the circuit so I checked it out. I was initially
> concerned because it has no snubber >
> >across the FET. So I checked the data sheet out for the device. I was
> impressed by its large safe operating
> >area and 0.5J single pulse avalanche energy capability. Truly a
transistor
> that's hard to kill. (but not
> >impossible)
>
> >Robert
>
> Robert,
> If only I have killed many of them, usually from spikes in the gate, they
> are very susceptible to HV..
>
> Although the circuit is similar to the one I used, being 30+ I have
actually
> used the good old 2N3055, which is apparently much easier to kill, maybe
its
> my experience, but i've only killed a couple in that circuit, and most of
> them are from shorts whilst playing, not "in service". I do have a 4nF cap
> and a reverse diode across then though.
>
> Cheers
> Derek
>
>