At 01:21 PM 4/25/97 -0600, you wrote:
> Have any Esteemed Reflectees had and experience using s/s relays
>with the zero-crossing detectors in them for use as part or all of a
>step/start AC input on amp supplies?
>
>Jim, KF7E
>Jim Henderson
>
Hi, Jim! Been there, done that, got the T-shirt! I love the SS relays for
turning on and off things. but they are far too fast for a step-start
circuit if used alone. You still need the 25 ohm resistor across the 250v
terminals. You can then derive the 5 vdc (or what ever the control voltage
rating on your relay is) from a dc supply downstream of the step-start relay.
You can adjust for the proper "hang time" by the value of the filter cap in
the dc supply. Two pair of the SS spst relays with separate supplies for
control will give you a completely silent, physically smaller circuit.
Just apply dc to the first pair, and it "does it's thing." Those SS relays
are appearing in the Dallas area in volume now, new surplus, at very
reasonable prices. A GREAT plus is that the "contacts" never get dirty!
Good switching!
(((73)))
Phil, K5PC
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