On Wed, 10 Sep 2008 22:36:28 +0000 (UTC), (Don
Klipstein) wrote:

In article , wrote:
On Wed, 10 Sep 2008 00:46:23 +0000 (UTC), (Don
Klipstein) wrote:

, wrote:
On Tue, 09 Sep 2008 16:58:09 -0400, Jeff Wisnia
wrote:

wrote:

On Tue, 09 Sep 2008 13:42:39 -0400, Jeff Wisnia
wrote:

SNIP to edit for space

And dimable LEDs ought to be a no brainer.

Jeff


Not nearly as easily accomplished as you think, Jeff.


I dunnno, you may be correct. This supplier says it can be a so-so thing
when using conventional pulse width varying dimmers.

http://www.besthomeledlighting.com/faqs

But I'm reasonably sure that compatible dimmers will become available
when LED bulbs really take off.

Jeff

The most reliable dimming at this point is to have an array of LED's
and make it so you can use varying portions of the array.

The delta from no light to full brightness is very short for LED's.
That makes effective dimming tricky at best.

Where do you get that idea?

- Don Klipstein )

Well, Don, I think you'll find that when you try to use a dimmer with
an LED, it's far from linear. You'll have to turn the dimmer up about
half way, and then the LED will come on, but it will not be dim, it
will start out at about half brightness. Then moving the dimmer a very
short amount (with a very steady and precise hand) you will go from
that stage to full brightness.

Try it, and you'll see.

I don't have any dimmers installed in my home, so I can't. However, if
current through an LED is varied, then the brightness varies roughly
proportionately. That much I do know - I have done that a lot.

It is much more expensive and difficult to make a high efficiency LED
lamp appear as a resistor load than otherwise, so that is why many/most
LED lamps do not dim really nicely with conventional dimmers.

However, that does not mean that either of these is untrue:

* LED lamps can be made to dim well with conventional dimmers, either
with increase in cost or a compromise in efficiency

* Dimmers can be made that dim LED lamps well

- Don Klipstein )

Please point me to somewhere I can buy these mythical LED dimmers. G