A number of gremlins cause the crow-bar to mis-fire. Just depends on
your specific regulator board version and part values used. One of the
reasons I came up with my replacment regulator board option.

http://www.repeater-builder.com/astr...ron-index.html

I've not seen a newer generation crow-bar circuit fail causing
equipment damage.. but as always your results might vary.

cheers,
s.

: A wrote:

: We had a thread recently on Astron power supplies and I thought I'd
: mention that I have an RS-35A (35 amps intermittent) for VHF brick
: amplifiers (main use) and I've had it for some 20 years. Recently, the PS
: has started to "crowbar" off on me (voltage goes to zero) and not even
: with high currents (maybe around 15 amps or so) and have to shut it off,
: wait a few seconds, and turn it back on.

: I also had another different regulated fairly high current DC PS go bad
: long ago, in a similar way.

: I'm wondering how many others of you have seen defective operation,
: sooner or later, or other deterioration in your high current regulated DC
: supplies?

: And, if the overvoltage crowbar craps out, it blows up your rig? I'm
: thinking of going exclusively back to deep cycle marine batteries, again.