Re: TRIAC dimmer control spreadsheet; was Re: Controlling Holiday Lights

[Marc_F_Hult <MFHult@xxxxxxxxxxxxxxxxxxxxx>]

On Wed, 1 Nov 2006 15:04:00 -0700, sylvan butler
<ZsdbUse1+noZs_0611@xxxxxxxxxxxxxxxxxxxxx> wrote in message
<slrneki6eg.a7n.ZsdbUse1+noZs_0611@xxxxxxxxxxxxxxx>:

>On Wed, 1 Nov 2006 09:24:03 -0700, Jon Woellhaf <jonwoellhaf@xxxxxxxxxxx>
wrote:
>> In dimming lights in a home, theater, etc., doesn't the human's non linear
>> response to light intensity need to be considered?
>
>As Robert posted, the "practical" way is to just set the light level you
>prefer.  It doesn't really matter if the dimmer is passing 80% or 20%,
>just so long as you can set it to get what you want.

This certainly applies to the end user. But folks that actually design dimmers
might initially choose a mathematical representation of the known physics for
design purposes. (I got the equations shown on my spread sheet from Chris
Pflieger, a design engineer at www.Touchplate.com about 5 years ago.)

>Mathmatically, it is even more complicated than just human
>non-linearities.  Incandescent lamps are also non-linear, and a
>mathmatically correct 50% reduction in power will reduce light far more
>than 50% in every case I know of.