Re: Controlling Holiday Lights

[sylvan butler <ZsdbUse1+noZs_0610@xxxxxxxxxxxxxxxxxxxxx>]

On Mon, 23 Oct 2006 11:25:18 -0400, Marc_F_Hult <MFHult@xxxxxxxxxxxxxxxxxxxxx> wrote:
> Or are you talking about lamps or LED's  operated on DC?
> Is so, there are DMX512->PWM and 0-10vdc analog-> PWM converters that
> modulate DC.

I'm modulating D.C., or rather, creating modulated D.C.  The technique
of modulating the D.C. is PWM.  That D.C. is then used to switch a
triac to control A.C. loads.  Phase syncronization is mainly needed to
control R.F. and sometimes to control switching transients.  With fairly
low power loads (typically under 200 watts) R.F. is minimal and
controllable in other ways.  Switching transients aren't significant
with primarily resistive or incandescent loads.

> There are of course many DMX512--> AC dimmer and 0-10vdc --> AC dimmers

You seem to be confusing how the dimmer is controlled (with DMX or
0-10vdc or...) with how the dimmer controls the A.C.  I'm doing the
latter.  Not real interested in the former at the present time.

> control and have begun investigating high-power LED's (the lamps are still to
> pricey for me at this time). LEDs are an arena for PWM in home lighting,
> especially when combined with RGB lighting control so that color as well as
> intensity can be controlled. High-power LED controller ICs are emerging eg
> from Maxim.

Yes, very cool stuff.  It is just beginning to hit the market, and looks
to have potential to revolutionize ambient lighting.

sdb

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