>Tks Andy, I printed that out.
>Question:
>Simple light dimmers are C/R time from '0' crossover to trigger triac.
>Theater (analog) dimmers are 0-10V control & 0-10V ramp into
>comparator
>to time from '0' xover.
>Even if controlled by DMX or other serial link, still electronically
>noisy because of A.C turn-on.
>Why not (using micro) always start on '0' crossover and leave out 1/2
>cycles.
>The more 1/2 cycles you leave out (alternate odd and even so load is
>balanced), the dimmer the light.
>Would this work? I've never seen it, but I may be re-inventing the
>wheel again.
>Comments?
>Mike
>
>>----------
>>From: Andrew Warren[SMTP:
TakeThisOuTfastfwdEraseME
spam_OUTIX.NETCOM.COM]
>>Sent: Wednesday, January 14, 1998 5:45 AM
>>To:
RemoveMEPICLIST
TakeThisOuTMITVMA.MIT.EDU
>>Subject: Re: Mains lighting control
>>
>>Montaigne, Mike <
PICLISTEraseME
.....MITVMA.MIT.EDU> wrote:
>>
>>> I am involved with our church's annual Singing Xmas Tree, where we
>>> have an choir put on a concert in a 6 level tree shaped pyramid.
>>> We use Xmas tree lights in 4 colors and some special channels as
>>> well, all on dimmers. .... we now want to remote the control pots
>>> and I now need dc control rather than R/C time constant control as
>>> we want to run the controls ~200 ft away from the triacs/power
>>> boards. .... it seems to me, I could run RS422 signals as well on
>>> two wires. Rather than re-inventing the wheel (fun but takes
>>> time), can any of you help me. Surely this has been done many times
>>> before - theater lighting etc.
>>
>>Mike:
>>
>>Yes, it's been done before; take a look at the DMX512 mini-FAQ at:
>>
>>
http://waapa.cowan.edu.au/lx/dmx-faq.htm
>>
>>-Andy
>>
>>=== Andrew Warren -
EraseMEfastfwd
ix.netcom.com
>>=== Fast Forward Engineering - Vista, California
>>===
http://www.geocities.com/SiliconValley/2499
>>
>