Re: X10 signals can be TOO strong!

["Jeff Volp" <JeffVolp@xxxxxxx>]

"Marc_F_Hult" <MFHult@xxxxxxxxxxxxxxxxxxxxx> wrote in message
news:j4p3o2pdau5f4ain79pt1u5dllldhpl6va@xxxxxxxxxx
> On Thu, 14 Dec 2006 22:56:43 GMT, "Jeff Volp" <JeffVolp@xxxxxxx> wrote in
> message  <LEkgh.204990$Fi1.128093@xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx>:
>
> >"Marc_F_Hult" <MFHult@xxxxxxxxxxxxxxxxxxxxx> wrote in message
> >news:u7i3o25pmcg42v8cp0co0dn8d75euuk7of@xxxxxxxxxx
> >>
> >> Another possibility is saturation of the inductor core at high
currents.
> >
> >I considered that, but there should be virtually no current to saturate
the
> >core before the triac switches on.  And even after the triac switches on,
> >the inductor would take some time to saturate.
> >
> >Jeff
>
> Apparently I misunderstand the problem posed,  which I thought included
the
> observation you made in the first post, namely:
>
> "  All three lamp modules exhibit the same characteristic with
> that heavy load. None of the modules flicker at all with a dimmed
> 75W table-lamp load, even at the same receptacle.  The lamp modules
> are from various eras. "
>
> "heavy load" implies high currents.

Yes, but core saturation is an instantaneous phenomenon.  The triac turns
off at each zero crossing, and current is virtually zero before the triac
switches on early.  I don't think core saturation can be an issue at that
instant.

I thought it might be thermal due to the heavy load.  There is some evidence
to support this.  After being on, and then ramped to max dim, the flicker is
more evident for awhile.  So the triac may be more sensitive to premature
triggering from dV/dt when hot.

Jeff