Re: X10 Interference from the Cellet Cellphone Charger

[nobody@xxxxxxxxxxxx (Dave Houston)]

While Insteon claims 10mV sensitivity, which would tend to make it more
sensitive to noise, it also has AGC which, in the presence of a stronger
signal, raises the threshold and suppresses noise. The repeater feature of
each Insteon module means there will always be a relatively strong (local)
signal (the more Insteon devices, the more ubiquitous the signal) when
compared to X-10. And Insteon uses Phase-Locked-Loop (PLL) which can recover
weak signals in a noisy environment. PLL also means Insteon has a narrower
bandwidth in comparison to X-10 devices (some of which can be blocked by
frequencies as high as 200kHz).

The bottom line is still what I said in my initial review of Insteon - while
Insteon is not immune to noise, noise will be less of a problem than it is
with X-10. OTOH, signal sinks will still be a (largely localized) problem
for both Insteon and X-10.

Note also that Jeff has not documented a valid spontaneously generated X-10
signal from the charger. It's still more likely that the noise somehow
operates directly on the microcontroller in the wall switches.

Jeff has implied (on the JDS forum) that the "X-10 Good" LED is evidence of
"spontaneous generation" but I think it's stronger evidence that the ESM1
does not check for manchester validity. Of course, I'm further inclined that
way since Paul Beam, who designed it, told me that it doesn't check
manchester validity. It might even be that the same phenomena that cause the
wall switches to turn on also cause the "X-10 GOOD" LED to turn on.

I'd like to see the relationship between the 60Hz signal and the charger
noise. A lightly loaded SMPS tends to draw current near the peaks of the
60Hz, midway between ZC points.

"BruceR" <razrbruce@xxxxxxxxxxxxxxx> wrote:

>For the record, the Cellet charger that I sent to Jeff never created any
>problems for my Insteon devices. It wasn't till it was plugged in at our
>other home equipped with 10 year old WS12A switches that the problem
>arose and even then it was localized to a couple of switches just a few
>feet away from the charger and presumably on the same circuit.
>
> Marc_F_Hult wrote:
>snip
>>
>> Looks like an INSTEON killer too (INSTEON self-repetition/signal
>> boosting notwithstanding).
>>
>snip
>