I once did a measurement of line voltage transients in an
industrial laboratory over a 24 hr period using a special
transient recorder which counted the number and sorted them
by amplitude. There were a number between 500 volts and 1kv
of short duration.The lab used quite a few temperature
controllers with triac and mercury relay switches.
I would use some sort of MOV's on the primary of a PS with
SS relays if they aren't already inside the devices.
I have always preferred large open frame relays which can
be checked visually.
On the other hand, I know of an accident when a technician
dropped a screwdriver which closed a power relay and destroyed
hard drives in the computer center of a major oil company in
Dallas. This occurred in a seismic processing center and caused
a multi million dollar loss of important data. I guess there is
no absolutely safe system.
73, Dan, N5AR
e: ss relays in amplifier hv supplies
>
> I've had a recent look at the new amplifier pics.
>
> One of the units shows the use of 3 solid state relays
> for control. I've always been worried about the use of
> ssr's around the combination of RF and Amplifier high
> voltage DC supplies.
>
> I do like the idea of using ssr's in HV power supplies,
> but their reliable application in QRO amplifiers has
> never been proven "100% safe" to me. Hence, I use
> mechanical types for the required application.
>
> I've experienced problems with ssr's which tend to
> "slightly leak" or turn themselves on, especially in the
> presence of high rf fields. I'd be curious to read
> (hear) comments from builder - users of ssr's applied
> to rf amplifier and related subject HV supplies here on
> amps. Have some of you sourced a reliable ssr that
> functions well in amp HV supplies.? Any special "hints
> or kinks" you've run into. I'd like to revisit ssr's in my
> next box should their hv ps application be viewed as
> "trustworthy."
>
> thanks
> skipp
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