Re: X10 Transmit Buffer

["Jeff Volp" <JeffVolp@xxxxxxx>]

Hi Bobby,

Thanks for the discussion.  Again, see my replies below:

"Robert Green" <ROBERT_GREEN1963@xxxxxxxxx> wrote in message
news:_MydnZSdbMBIk__ZnZ2dnUVZ_s2dnZ2d@xxxxxxxxxx
> "Jeff Volp" <JeffVolp@xxxxxxx> wrote in message
>
> <stuff snipped>
>
> > The waveform is near sinesoidal.  I don't have a spectrum analyzer
> > to determine its harmonic content.
>
> Sorry.  I was unclear.  A while back I looked at a lot of screen shots
done
> by Dave H. and others that indicated some unusual characteristics for the
> CM11A when compared to a TW523 or a Maxicontroller.
>
> AFAIK (and that ain't much!) the CM11A, besides having lower output
voltage
> than most controllers, also suffers from a peculiar output voltage decay
> during the signal transmission itself.  I would assume since you're able
to
> boost the signal to a uniform output level despite varying input voltages
> that the XTB X-10 signal will not contain the original transmitter's
> waveform flaws.  I just wanted to be sure a CM11A plugged into the XTB
> device would NOT show the same voltage drop during its output burst.

Ah, now I understand.  I sent you a snippet of my simulation by e-mail so
you can see the waveform itself.  What doesn't show in that snippet is that
there is about 5% voltage decay over each 1mS burst as energy is pulled from
the primary storage capacitor.  It has an unregulated full-wave bridge
supply, and recharges on each half cycle.  The normal X10 capacitor supplies
recharges once a cycle, and their practical limit is around a watt.  Also, a
capacitor supply must dissipate that power continually.  An unregulated
transformer supply such as used in the XTB has minimal dissipation except
when actually driving a load.

> I'm sorry if I am being a pest about the CM11A but I think your device
will
> have appeal to those who like that controller but do not like repeaters.
If
> you don't own a CM11A, I'd be happy to loan you one for testing.

I'm glad you brought up the CM11A, and it is an excellent application for
the XTB.  I had used one at the old house before beta testing the CM14A.
I'll locate it and do some testing in the next couple of days.

> It's probably better that you discover any unusual device interactions
> before anyone else does!  IIRC, (but probably not) the CM11A very
> occasionally self-immolates in the presence of certain sorts of dimmers,
or
> at least I vaguely remember reading reports of serious CM11A overheats for
> one reason or another a few years ago.

Yes, I remember all those too.  It was fairly reliable for me, but I did
have to do the cold reset every couple of months.

> Great job, BTW.  Why didn't someone do this 20 years ago?  Were the
> components or the brainpower not available back then?

Signal suckers have gradually become more and more of a problem as they
proliferate through the average household.  And X10 must do everything as
cheaply as possible to hit their target market.  Others have taken a
different approach, requiring a significant expense in new equipment.  Of
course, it is to their benefit have homeowners rip out all their X10
equipment so they can sell them new stuff.  My goal is to improve the
reliability of existing X10 systems by addressing the signal level issue
with minimum effort and expense.

Jeff