Re: I think they've done it again.

[nobody@xxxxxxxxxxxx (Dave Houston)]

"Robert Green" <ROBERT_GREEN1963@xxxxxxxxx> wrote:

>"Keep thinking Butch, that's what you're good at!"  :-)

I'm not sure whether that's a reference to "Butch the Bulldog" or someone
else. ;-)

A consensus seems to be forming among those seeing the flickering that it
only occurs when a switch has more than ~250W (total) connected and is
dimmed to 50% or less.

This puts the triac switching point near the peak of the line voltage and at
the furthest point (in time) from the Insteon control signal. That the triac
is being turned off at this point is the least likely explanation as the
current, being at or near maximum, is almost certainly far above the triac's
holding current.

This is also the area where triac switching noise will be at a maximum. An
undersized choke could allow this noise to reach the PIC (in the subject
switch or in other devices on the line) and this might cause the PIC to
stutter and miss a half-cycle or more. (The PIC has to actively turn the
triac on for each half-cycle.) Earlier Smarthome designs (e.g. 1132B and
2000STW) have been overly sensitive to disruption by out of band noise.