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

["Robert Green" <ROBERT_GREEN1963@xxxxxxxxx>]

"isw" <isw@xxxxxxxxxxx> wrote in message
news:isw-B6D8FD.20224806062008@xxxxxxxxxxxxxxxxxxxxxxxxx
> In article <1348346@xxxxxxxxxxxxxxxxxxx>,
>  ddl@danlan.*com (Dan Lanciani) wrote:
>
> > In article <isw-3AB4BB.10494406062008@xxxxxxxxxxxxxxxxxxxxxx>,
> > isw@xxxxxxxxxxx (isw) writes:
> > | In article <hpqdncmhFKn1b9XVnZ2dnUVZ_gWdnZ2d@xxxxxxx>,
> > |  "Robert Green" <ROBERT_GREEN1963@xxxxxxxxx> wrote:
> >
> > | > As I understand it now, the pulse to the triac has to occur twice
every
> > | > cycle and has to be alternatingly negative and positive to allow
each
> > | > half
> > | > of the AC cycle to pass.
> > |
> > | The pulses do not have to alternate in polarity; that's one of the
neat
> > | things about triacs.
> >
> > Though it is possible that you might want them to alternate to stay in
> > the optimal triggering quadrants.
>
> The triggering sensitivity is different, but the triac can always be
> triggered.
>
> > | > It sounds like the mod that uses the alternistor and the
optoisolator
> > | > does
> > | > just that.  It seems that the optoisolator extracts the ZC data and
then
> > | > the
> > | > additional circuitry creates its own full width pulse independent of
> > | > whatever length pulse comes out of the IC.
> > |
> > | It sounds like you're attributing too much functionality to the
> > | optoisolator; it doesn't *extract* anything. It's just a transistor
that
> > | turns on when light shines on it. And the light is the LED that's
inside
> > | it. The output of the opto just repeats whatever is on its input while
> > | isolating the possibly dangerous voltage levels on the input side.
> >
> > The MOC3042 used in the modification is more than a simple optoisolator;
>
> Yes, it is. I was not aware that was the device being used. Since the
> output of the X-10 unit's IC is already phase synchronized, it's not
> clear why something like that is necessary though.

Are you saying they could have taken the IC output and processed it so that
as soon as a pulse was detected, the triac would be gated on until the next
ZC?  I'm not sure I follow . . .

--
Bobby G.