Re: Controlling Holiday Lights

[ddl@danlan.*com (Dan Lanciani)]

In article <slrnekfbic.bco.ZsdbUse1+noZs_0610@xxxxxxxxxxxxxxx>, ZsdbUse1+noZs_0610@xxxxxxxxxxxxxxxxxxxxx (sylvan butler) writes:
| On 28 Oct 2006 20:33:23 GMT, Dan Lanciani <ddl@danlan.*com> wrote:
| > In article <slrnek5vme.vse.ZsdbUse1+noZs_0610@xxxxxxxxxxxxxxx>, ZsdbUse1+noZs_0610@xxxxxxxxxxxxxxxxxxxxx (sylvan butler) writes:
| >| If I instead trigger at 1000/sec, that is a max of 4% error when it
| >| happens at random instead of synchronized to zero crossings.  This error
| >| has imperceptible effect (to my eye when using incandescent lighting).
| >
| > What (not synchronized to the zero crossing) triac trigger waveform
| > will you synthesize to obtain an approximately 50% dim level?
|
| I don't know up front, that is a software calibration issue related to
| the lamp being controlled and visual perception.
|
| If you meant 50% power level rather than 50% light level,

I didn't, but indeed the 50% power level question is more appropriate
for discussion purposes as it does not require knowledge of the light
output to power mapping.

| then I would
| synth a 50% on-time, and know that with a 4% error limit I would be
| close enough.  But again, that is power, not light.

Power at 50% is fine, but can you describe the actual waveform that you
would synthesize to trigger the triac?

				Dan Lanciani
				ddl@danlan.*com