[AMRadio] Reduce relay contact arc

[Rob Atkinson]

I went through this a few years ago.   The usual solutions are
snubber, inrush limiter with a resistor, or a thermistor.   The all
work to some degree but in different ways and circumstances.  A
thermistor works, but runs hot and won't do anything if the relay is
closed and opened repeatedly before the thermistor can cool down to
recycle.   All these methods may or may not prevent arcing on break.
I wound up using a solid state hocky puck SPST circuit.

73

Rob
K5UJ

On Wed, Jun 13, 2018 at 9:08 AM, CL in NC via AMRadio
<amradio at mailman.qth.net> wrote:
> If you have a relay that is switching line voltage or higher AC voltage, is there any way to reduce the arcing?  You might suggest a snubber, but if you use the snubber formula to calculate component sizes, the capacitor allows enough AC to pass such that your transformer is making volts.  You put it on the primary of say a HV B+ PS, and you will get some amount of B+ on the secondary, and if you put it in the secondary HV line, you will leak AC into the rectifiers and still make B+.  Any solutions other that something like a .01 across the contacts and live with it?
>
> Charlie, W4MEC in NC