Re: Buzzing relays? Anyone help?

[kimble <kim@xxxxxxxxxxxxxxxxxx>]

mailinglists wrote:

> At a guess I'd say that the leakage current from the modules is enough
> to make coils buzz. The problem is exacerbated by the relays being on
> one side of a plasterboard partition wall, which seems to amplify the
> buzz into the next room. Aside from the buzz everything else seems to
> have worked just fine for the last few weeks.
>
> The $64K question is how to stop the buzz? Any ideas?

Not being familiar with X10 appliance modules, but assuming they're
doing the usual semiconductor switching shenanigans, an old trick for
running very small or inductive loads from theatrical dimmers[1] springs
to mind... try sticking a load (lightbulb or similar, experiment with
values) in parallel with the relay coils.


kim.

[1] These beasts are typically rated at between 2 and 5kW, and often
have a loose interpretation of 'off' (either due to pre-heat[2] current,
or  an artefact of the dimmer design), which can cause problems when
trying to run christmas tree lights or anything with a DC power supply
(the latter only being something you'd want to do with the channel set
to non-dim mode).

[2] The dimmer keeps the lamp filament at 'barely glowing' when 'off' so
that the lamp is quicker to respond - some of these things have
impressive thermal inertia.