Re: I think they've done it again.

[nobody@xxxxxxxxxxxx (Dave Houston)]

Yes, I think Dan Lanciani and I are saying something similar but I'm
suggesting that the triac noise at mid-cycle is triggering a false reaction
by the PIC (assuming it's a PIC) that then prevents it from turning on the
PIC during the following half-cycle(s).

I have a NEC Multisync XV15 monitor which outputs noise of an unknown (to
me) spectra. When connected to the same power circuit as the NEC monitor,
the initial Powerlinc 1132B goes deaf to the powerline. With the 1132B
powered by a different circuit it works OK.

I have 3 Lamplinc 2000STW modules. None work reliably on the power circuit
with the NEC monitor - their LEDs flash randomly and they respond to PLC
commands intermittently. All work normally when powered by a different
circuit or when the NEC is powered down.

At the moment I have two Insteon Powerlinc 2414S PC interfaces and two
LampLinc V2 2456 modules. The LEDs on all flash randomly when connected to
the circuit with the NEC monitor but are rock steady when powered by a
different circuit or when the NEC monitor is off.

Plugging the NEC monitor into a Leviton plug-in filter reduces the LED
flicker on most of the devices and 2 of the 3 Lamplinc 2000STWs appear to
work OK. Adding a John M. Jones homebrew filter (just the choke from an X-10
lamp module) in series with the plug-in filter eliminates the LED flickering
on all of the Insteon modules and the 3rd Lamplinc 2000STW starts working.

No noise shows up on my 'scope using the ACT Scope-Test2 (tuned for X-10).
Triac switching transients from my dimmers do show on the 'scope. All of my
X-10 modules work with no problem in the circuit with the unfiltered NEC
monitor.

I suspect they have a fundamental design flaw that causes their devices to
be affected by out-of-band noise (or by very low level in-band noise) and
that they have carried this flaw through all of their designs.

The published signal sensitivity spec for all of their modules is in the
10mV or lower range so this might also be a factor.

With the 1132B and the 2000STWs, it appears that they get into a state where
they are expecting additional input that never comes or that they get out of
the state but another noise pulse triggers it again almost immediately.

"Robert Green" <ROBERT_GREEN1963@xxxxxxxxx> wrote:

>> 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.
>
>I believe Dan had also mentioned this unwanted PIC interaction as a possible
>cause for the flickering.  FWIW, this seems to be the likely explanation
>because reports indicate the V2's are emitting EMI that's extending well
>beyond the local circuit.  Something's leaking out of the V2's that's strong
>enough to fool nearby devices into behaving erratically.  There's not much
>other than EMI and voltage fluctuations to explain flickering.   I believe I
>read that the EMI placed on the line by a triac is 90 degrees out of phase
>with the original AC cycle.  Is that what's causing nearby dimmers to
>flicker?