Re: X10 signals can be TOO strong!

["Jeff Volp" <JeffVolp@xxxxxxx>]

"Alan Vogel" <avogel2@xxxxxxxxxxxxx> wrote in message
news:6e5gh.30252$wP1.27181@xxxxxxxxxxxxxxxxxxxxxxxxxxxxx
> It looks like the 30Vpp signals that appear on the MT1 and MT2 pins of the
> triac are exceeding the triac's dV/dt spec.  These signals capacitively
> couple to the triac's gate and turn it on.  Sensitive gate triacs
typically
> have higher dV/dt limits, but are probably not used in the modules because
> they are more expensive.

That makes sense.  The inductor in series with the triac should limit the
dV/dt, but perhaps not enough.  I recall Insteon had to change an inductor
to resolve their flicker problem.  I don't understand why this seems to
effect modules running near their maximum load.  Of all the switches and
modules in the house, only this one exhibits the effect.

Like you say, it may be that the least expensive triacs are used in these
modules.  We have an older Leviton 6343 "red line" X10 wall switch on the
same circuit as the XTB-II, and much closer than the misbehaving X10 module.
It has an even heavier load, but doesn't exhibit any flicker.  However, that
Leviton switch was not targeted at the low end market, and may have better
grade components.

Jeff