At 1/17/2007 11:37 AM, you wrote: > > A long time ago I happened to find a crowbar "bar" made by Lambda at the > > local TRW swap meet. I added it to a supply without built-in OVP to add > > said protection to the equipment. I wonder if similar devices are > > commonly > > available somewhere? That & a fuse on the output of an SEC-1223 & I think > > I'd feel comfy using it at one of my sites. > > > > Bob NO6B > >Bob, > These crowbar circuits are quite simple to design and build. They >usually consist of a large SCR, a zener diode, one resistor, and an optional >capacitor. Of course a fuse upstream somewhere is a great idea, too. A heat
Yes, I know - I've designed & built a few for some pricey amplifiers we use at work. I'm just looking for something I can slap on an existing P.S. without having to worry about building, packaging etc. > >sink is not necessary because of the very short duty cycle. Actually, some heat dumping is required since when they fire they sink several amps of current & do have a finite voltage drop across them. Not much, but enough to need a little heat sinking. Bob NO6B
