" wrote in
:

On Sun, 26 Dec 2010 01:09:29 -0600, G. Morgan
wrote:

wrote:

Resistors heat == inefficient

But the resistor will always be there. You are just making a bigger
resistor, the current will drop and the light will dim in a vary
linear way.
The voltage you drop across your resistor will be the same no matter
how big it is. That is not like a rheostat on an incandescent where
you are changing the voltage applied todrop the filament.

The voltage across the resistor *does* change. Also, P=I^2R.

How does the voltage change across a fixed circuit? I think
everyone here is talking about an Xmas tree lighting situation
(now), in a series arrangement.

He's talking about dimming LEDs, as in under-cabinet lighting.


those are not single LED's,they are LED arrays.
Probably parallel strings of LEDs.

--
Jim Yanik
jyanik
at
localnet
dot com