Re: X10 signals can be TOO strong!

[nobody@xxxxxxxxxxxx (Dave Houston)]

"Jeff Volp" <JeffVolp@xxxxxxx> wrote:

>I built a simulation of the AC distribution network in a typical home using
>inductance based on wire length.  The numbers were from the audio guys whose
>high power speaker cables are similar in dimensions to Romex.  I also added
>distributed capacitance and a few signal suckers.  It is easy to see from
>that simulation why the signals fall off as they do.  An AC distribution
>network is basically a very complex low-pass filter that has various peaks
>and nodes throughout the system.  The nodes are the "black holes" where it
>is virtually impossible to get a decent signal without moving the
>transmitter.

There have been numeroous white papers published by various academics and by
engineers at companies looking at developing powerline products that treated
the powerline as a communications medium. I have cited many of them many
times in c.h.a. over the past few years.

Most of them dismiss the inductance of the wire itself. They mostly felt the
inductance of the terminations and the capacitance of various loads were the
important factors.

>Since Insteon is based on having multiple transmission points, signal
>strengths throughout the network should be more constant.

Agreed, but I'm sure there have been at least a few occasions in the past 30
years with all the many millions of X-10 modules in use when an X-10 signal
reaching a dimmer (X-10 or otherwise) was at least as high as the average
Insteon signal. Why haven't we heard of flicker before this?

FWIW, my ESM1 measurements around my rather large apartment do not show the
degree of attenuation you see. Unfortunately, I'm no longer able to do the
amount of walking required to repeat the measurements but as best I recall,
using a TM751 as the source, I had at least 2-3V at all outlets after adding
one filter on my TV/VCR and associated gear.

http://davehouston.net
http://tech.groups.yahoo.com/group/roZetta/
roZetta-subscribe@xxxxxxxxxxxxxxx