Re: Making an X-10 lamp module immune to dimming

["Robert Green" <ROBERT_GREEN1963@xxxxxxxxx>]

"isw" <isw@xxxxxxxxxxx> wrote in message
news:isw-CBF42F.10034506062008@xxxxxxxxxxxxxxxxxxxxxxxxx

<stuff snipped>

> > If I understand this correctly, it doesn't matter what the width of the
> > pulses coming out of the X-10 IC are.  Nor does it matter how many small
> > pulse occur within each half cycle.
>
> That is correct.
>
> > When the ON signal arrives at the
> > module, current starts flowing because the current used to power the
gate
> > circuit is activated.
>
> As successive "brighten" commands are sent, the leading edge of the
> first pulse moves to occur earlier in the half cycle, so the triac is
> turned on for progressively greater percentages of time -- and the lamp
> grows brighter.
>
> >  However, it no longer gets any information about the
> > bright or dim levels because the triac is "beating" to the ZC data that
now
> > comes from the optoisolator/AC powerline instead and not the IC output.
Is
> > that correct?
>
> X-10 commands are sent right at zero crossings, so the triacs in all the
> modules are "off".
>
> > I assume what turns the module off is an OFF command that
> > interrupts the output from the optoisolator so that there's no longer
any
> > pulses being sent.  I thought Isaac said there was always a pulse going
to
> > the triac, even when the unit was off.
>
> I did. But that pulse occurs so late in the half cycle that essentially
> no energy gets to the lamp -- just a tiny "blip".

I just wanted to prove I was paying attention.  (-:  I that I at least have
a little sense of what turns the triac on and off and how dimming is
accomplished.  I have to confess that I am still a little hazy on how the
module itself turns on and off and just how the sequence of events occurs
from button push to lamp lighting.

--
Bobby G.