Re: I think they've done it again.

["bruceR" <nospam@xxxxxxxxxxxxx>]

FWIW, perhaps I should mention here that the "flickering" - at least in my
case - is a very brief (guessing 100ms twice) brightening of a dimmed load
rather than going dim or dark.

  <nobody@xxxxxxxxxxxx>wrote:

> 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?