Kibo informs me that Nick Hull stated that:

In article , CJT
wrote:
I'd look closely at your automatic switch. Perhaps it's generating
an RF pulse when it switches state that is somehow reaching your
inverter. The solution might be as simple as a capacitor across the
switch, or a cheap filter between it and the inverter.

My 'automatic switch' is just a DC relay powered from the AC mains with
rectification and a capacitor. If the power fails the cap will hold the
relay in for 10 seconds, then it drops out to energize the CF light. I
don't see any RF pulse there, do you?

Unless you quench it somehow, you'll get a big voltage spike, (resulting
in an RF glitch), any time a coil (such as your relay) is switched off.
Does the coil of the relay have a diode or cap across it to sink the
spike? If not, that may well be the cause of your problem.

When switching heavy loads with a relay, it's also good practice to put
an RC supression circuit across the contacts to prevent sparking, which
will generate RF, as well as being bad for the contacts.

--
W
. | ,. w , "Some people are alive only because
\|/ \|/ it is illegal to kill them." Perna condita delenda est
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