Hi Gary, I have tried using solid state relays in that application with
poor reliability. The last attempt was a 70A unit that worked ok for a while
but a flashover in the plate circuit took it out in a shorted condition. The
B+ lead had a 50 ohm current limiting resistor installed but that was not
enough. 30A fuses in the primary also blew.
I have since replaced the solid state relay with a 30A mechanical relay and
no further problems have come up.
73,
Gerald K5GW
In a message dated 3/4/2010 2:53:40 P.M. Central Standard Time,
garyschafer@comcast.net writes:
Has anyone had problems using a solid state relay to short out the step
start resistor in a power supply?
I have heard of problems of not enough current thru the SS relays (when amp
is in standby) when used as the primary on/off relay. Sometimes a resistor
has to be placed in parallel with the transformer primary so the relay
works
properly.
When used in a step start circuit the current could be quite low as well as
the voltage at the relay due to the resistor across the relay. Any issues
here?
73
Gary K4FMX
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