TexasRF@aol.com wrote:
>
> 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.
>
If need be you can always use a solid state timer to control a
mechanical relay(s).
73
Roger (K8RI)
>
> 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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