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

[isw <isw@xxxxxxxxxxx>]

In article <vv6dndt5m7sEbMnVnZ2dnUVZ_sLinZ2d@xxxxxxx>,
 "Robert Green" <ROBERT_GREEN1963@xxxxxxxxx> wrote:

> "isw" <isw@xxxxxxxxxxx> wrote in message
> news:isw-B62626.10184909062008@xxxxxxxxxxxxxxxxxxxxxxxxx
> <stuff snipped>
>
> >> Are there other devices that can interrupt current flow with a gate
> >> trigger?
>
> > Yes. There are gate-turn-off (GTO) thyristors:
> > http://en.wikipedia.org/wiki/Gate_turn-off_thyristor
>
> So that's how my auto-thyristor flash works!
>
> > > > Right on. But think about how a half-sine looks -- a linear increase
> in
> > > > on-time does NOT result in a linear increase in power delivered to the
> > > > load.
> > >
> > > Right.  This looks very much like an "area under the curve" sort of
> problem.
> >
> > Close, but more complex, because the load (assuming an incandescent
> > lamp) is not constant. The resistance of a lamp filament is lowest when
> > it's cold (which is why a burn-out so often occurs when it's switched
> > on), and rises as the filament heats up.
>
> I see
> >
> >>>> So it might even be possible it's really just noise with no particular
> >>>> function but no particular harm to the operation of the module.
> > > >
> > > > It's not noise; it's a regular string of pulses.
> > >
> > > I thought that any signal other than the one you wanted could be
> > > considered noise.
> >
> > That's a simplistic definition, although it sometimes works.
>
> I'm a simplistic guy.  (0:  I assume the anything that is non-random
> shouldn't really be called noise.

I think so, but sometimes it can be *really* hard to tell the difference
(cf. "pseudorandom"). Pseudorandom patterns are regularly used for
encryption. If they were *truly* random ,they wouldn't be very useful,
but if their pattern could be determined, even with great effort, they
would be worthless.

Isaac