Re: X10 signals can be TOO strong!

[Marc_F_Hult <MFHult@xxxxxxxxxxxxxxxxxxxxx>]

On Thu, 14 Dec 2006 19:03:32 GMT, "Jeff Volp" <JeffVolp@xxxxxxx> wrote in
message  <8ehgh.491908$QZ1.430735@xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx>:

>"Jeff Volp" <JeffVolp@xxxxxxx> wrote in message
>news:qtdgh.203122$Fi1.110592@xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
>
>> Like you say, it may be that the least expensive triacs are used in these
>> modules.  We have an older Leviton 6343 "red line" X10 wall switch on the
>> same circuit as the XTB-II, and much closer than the misbehaving X10
>> module. It has an even heavier load, but doesn't exhibit any flicker.
>> However, that  Leviton switch was not targeted at the low end market, and may
>> have better grade components.
>
>Update - I had not dimmed the Leviton enough to see the flickering.  It does
>it too.
>
>There is a recent thread on the HomeSeer board about the Insteon flicker.
>One user reduced the load by unscrewing a few bulbs, and the problem went
>away.  Another reported there was still some minimal flicker even with the
>modified Insteon switches.
>
>The problem may be more evident in an Insteon system because every module is
>also a transmitter.  So average signal levels are apt to be much stronger
>than a typical X10 system.  Here the flicker occurs on two heavily loaded
>dimmers on the family room branch circuit with its very high signal levels.
>With the XTB-II in its normal location by the distribution panel, we never
>saw flicker anywhere.

Jeff,

I previously posted to c.h.a. my experiments with a 12-lamp chandelier that
allows me to create any load between 0 and 720 watts in 15 watt increments.
The  original-version V2 INSTEON dimmer powering the lamp could be made to
flicker. I had not experienced it prior to the experiments because the load
wasn't great enough in normal use/configuration/wattage. The  replacement
INSTEON V2's don't flicker..

In a different post to c.h.a., I speculated that the 'fix' that SmartLabs might
institute would be to add more turns to the existing inductor. As best I can
determine, that is exactly what they did -- leastwise the replacement units
appear to be identical, with an identical inductor core, except for more turns.

This suggests that the 'fix" that I also suggested (and SmartLabs also
apparently contemplated recommending but decided against) of adding inductance
externally in series would also work to solve flicker issues.  One could do this
with an inductor salvaged out of an old dimmer (eg WS-467 or non-X-10) connected
to stranded 16AWG wire and insulated with a single piece of ~3/4" heat-shrink
tubing. There are also lotts toroid cores on the surplus market, but color codes
of core composition and properties are not standardized so obtaining appropriate
cores may require some sleuthing unless one is willing to pay full price.

It should be noted that the problem of unintended turn-on of TRIACs is as old as
TRIACs themselves. This is why virtually all TRIAC dimmer circuits use some sort
of snubber circuit to prevent self-triggering. I am skeptical of the conclusion
that the problem has to do with the 'quality' ("least expensive") of the TRIACs
used.

It may very well be that the folks at Pico what thunk up X-10 to begin with
considered the issue when they chose the maximum voltage for the X-10
transmitters.

Comparisons of the output of the TW-523 and CM11a in this newsgroup (the CM11a
has roughly 1/2 the voltage output of the TW-523 that it followed) have implied
that there was something wrong/inferior with the CM11a. Lower voltage would
further mitigate the flicker problem (if any).

It is also useful to note that when ACT designed the TI-103 series of
transmitter/couplers, they beefed up the current available using a transformer
so as to be able to drive low impedance loads, but spec 'd the output at 6
volts, presumably on purpose, and perhaps to avoid the flicker problem. T' would
be useful to inquire, and they/ Uncle Phil might respond since they are
(apparently?) gitting out of the X-10 arena.

... Marc
Marc_F_Hult
www.ECOntrol.org