[Amps] contact bounce

[Dieter Horst]

Hello Larry, 

nearly 2 years ago, I did some measurements on Siemens VR311 (aka Jennings RJ1A) 
vacuum relays. Reason was exactly what you describe, to slow down the input
relay of a PA.

It turned out that the ON delay was

2.5 ms @ 24 V
3.3 ms @ 18 V 

and OFF delay was

4.5 ms @ 24 V
3.7 ms @ 18 V

I would assume that with your RJ6B you can expect similar results. Just find
someone with a digital scope and have your relay measured at different voltages.
After that choose a resistor for your input relay and your problem should
be gone forever. 

I have (a german) report about my measurements which a can send directly 
to you and others if interested.

73

Dieter DL5RDO




> Hey guys,

> I have an amplifier that uses a Jennings RJ6 relay in both the input and
> output circuits. About once every two years I have to change the output
> relay.  Since both relays switch at the same speed the output relay tends
> to arc
> during  the contact bounce stage of its cycle. This has been confirmed by
> Jennings when  I sent back a bad relay and they opened it up to confirm
> the
> failure.

> My idea is to slow down the input relay slightly to save the output relay.
> I dont think that the input relay will fail when hot switching the 200
> watts RF  input where the output relay which switches 2 KW has problems.

> If you agree with my thinking then can anyone suggest a simple solution to
> slow the input relay switching.

> The relays are Jennings RJ6B and operate at 24 VDC.

> Thanks,
> 73
> larry
> n7dd
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