Seems like thyratrons have become quite rare these days
and SCRs or GTOs are just too freaking slow.
Is there a readily available alternative[...]under $100?
A kilovolt would be nice and >50A.

Hey guys,

Seems like thyratrons have become quite rare these days and SCRs or GTOs
are just too freaking slow. Is there a readily available alternative
that doesn't cost an arm and a leg, meaning under $100? A kilovolt would
be nice and >50A.

--
Regards, Joerg

http://www.analogconsultants.com/

"gmail" domain blocked because of excessive spam.
Use another domain or send PM.

Hey guys,

Seems like thyratrons have become quite rare these days and SCRs or GTOs
are just too freaking slow. Is there a readily available alternative
that doesn't cost an arm and a leg, meaning under $100? A kilovolt would
be nice and >50A.

Hey guys,

Seems like thyratrons have become quite rare these days and SCRs or GTOs
are just too freaking slow. Is there a readily available alternative
that doesn't cost an arm and a leg, meaning under $100? A kilovolt would
be nice and >50A.

Hey guys,

Seems like thyratrons have become quite rare these days and SCRs or GTOs
are just too freaking slow. Is there a readily available alternative
that doesn't cost an arm and a leg, meaning under $100? A kilovolt would
be nice and >50A.

On Mon, 05 May 2008 13:40:11 -0700, Joerg
notthisjoergsch at (no spam) removethispacbell.net> wrote:

Hey guys,

Seems like thyratrons have become quite rare these days and SCRs or GTOs
are just too freaking slow. Is there a readily available alternative
that doesn't cost an arm and a leg, meaning under $100? A kilovolt would
be nice and >50A.

IGBT? IIRC, 1-1.5kV is available.

Joerg wrote:

Hey guys,

Seems like thyratrons have become quite rare these days and SCRs or
GTOs are just too freaking slow. Is there a readily available
alternative that doesn't cost an arm and a leg, meaning under $100? A
kilovolt would be nice and >50A.

A thyratron is a switch as I recall. How about two
or three cascaded FETs ? The circuit is called Marx
stack I believe and achieves few ns out of ordinary
FETs by avalanching them. 50 Amps are hefty though.

On Mon, 05 May 2008 13:40:11 -0700, Joerg
notthisjoergsch at (no spam) removethispacbell.net> wrote:

Hey guys,

Seems like thyratrons have become quite rare these days and SCRs or GTOs
are just too freaking slow. Is there a readily available alternative
that doesn't cost an arm and a leg, meaning under $100? A kilovolt would
be nice and >50A.

How slow is "too freaking"? The Russians still make some nice hydrogen
thyratrons; Los Alamos used to buy them on the sly, maybe still do.

You can get 1KV from one or two mosfets, tens of amps in a few ns. A
string of maybe 3 avalanche transistors, like the Zetex SOT-23's, will
output 30 amps or so at 1KV, for short pulses.

I did one gadget that puts 1200 volt pulses into 50 ohms, 2400 volts
into a small capacitive load, with 3 ns pulse width, at up to 500 KHz.
It uses a drift step-recovery diode (another Russian invention) driven
by a couple of 400 volt mosfets.

http://www.highlandtechnology.com/DSS/T220DS.html

It was fun, but we didn't sell many.

Hey guys,

Seems like thyratrons have become quite rare these days and SCRs or GTOs
are just too freaking slow. Is there a readily available alternative
that doesn't cost an arm and a leg, meaning under $100? A kilovolt would
be nice and >50A.

I need to switch within 100nsec or so.
..

In my case a FET would work, that's what I am trying right now. But it
ain't ideal because it should turn off when a certain resonance has run
its course, not when a gate driver tells it to. In a pinch I can try
some nifty feedback for that, and maybe I have to.

On Mon, 05 May 2008 13:40:11 -0700, Joerg
notthisjoergsch at (no spam) removethispacbell.net> wrote:

Hey guys,

Seems like thyratrons have become quite rare these days and SCRs or GTOs
are just too freaking slow. Is there a readily available alternative
that doesn't cost an arm and a leg, meaning under $100? A kilovolt would
be nice and >50A.

---
Try these guys...

http://catalog.rell.com/rellecom/scripts/GroupMembers.asp?manu=&product=788&T1=5&T2=3&SK1=thyratron&SK2=+&maxrecs=50&T3=2&prevkey=+&recfirst=0&reclast=0&searchtotal=%2D1

On Mon, 05 May 2008 16:45:33 -0700, Joerg
notthisjoergsch at (no spam) removethispacbell.net> wrote:

I need to switch within 100nsec or so.
.
.
.

In my case a FET would work, that's what I am trying right now. But it
ain't ideal because it should turn off when a certain resonance has run
its course, not when a gate driver tells it to. In a pinch I can try
some nifty feedback for that, and maybe I have to.

---
I'm confused.

From what you've said, it seems you want to ring a bell and keep the
clapper stuck until the amplitude of the ring decays to less than some
reference threshold, then you want to release the clapper and start
the cycle over again.

Am I right?

Joerg wrote:
Seems like thyratrons have become quite rare these days
and SCRs or GTOs are just too freaking slow.
Is there a readily available alternative[...]under $100?
A kilovolt would be nice and >50A.

Beefier than this starts to get slow.
http://www.google.com/search?q=Advanced.Power.Technology+1000V+28A+APT10035B2LL
IIRC, these are in the $30 range.

Seems like thyratrons have become quite rare these days and SCRs or GTOs
are just too freaking slow. Is there a readily available alternative
that doesn't cost an arm and a leg, meaning under $100? A kilovolt would
be nice and >50A.