wrote in message
ups.com...
Hi gang,

Is it not feasible to use a crowbar circuit across a PSU's output if
that PSU has a current-limiting feature? I can imagine a situation
arising where an over-voltage causes the crowbar to close, generating a
short-circuit condition which activates the current limiting. The
output will then be stuck at not enough amps to blow the upstream fuse,
but enough current to smoke the crowbar (which is not designed to be
kept conducting for any length of time of course). Is there some way to
have both over-current and over-voltage protection working together in
harmony?
Thanks.
p.


Look up the Astron supplies. They will go into a current limiating mode if
the over voltage protection activates. That is if there is a spike or
something. Most of the time something fails (say the pass transistors) that
makes the supply go into the over voltage condition and due to the failed
component the supply can not go into the current limit mode.