"John B." wrote:

On Sat, 04 Aug 2012 10:25:10 -0400, "Michael A. Terrell"
wrote:


"John B." wrote:

A great many of those 12 VDC lights are just series circuits made up
of LED's and resisters. Try a resister in series with one side of the
circuit. It may well dim your lights. If that works you can replaced
the resister with a variable resister (potentiometer, rheostat,
whatever) for finer control.


Can and should are two different things. The proper way to dim them
is with a PWM controller which is dirt cheap on Ebay.

How so "proper"? More efficient as no resisters used to generate heat
but the O.P just wanted to make the lights less bright and a rheostat
will do that with the usual 12 VDC LED lights.


He would need a wirewound Rheostat, and the control would be very
touch, since LEDS are current operated devices, unlike incandescents.
They will change brightness with temperature changes when such a crude
method id used. A decent Rheostat willl cost more than a PWM
controller. Some LEDs will start to emit light at the microamp level.