On Mon, 19 Oct 2009 22:55:19 +0000 (UTC), (Don
Klipstein) wrote:

For lamps bright enough for general illumination, such as 40 watt
incandescent equivalent, I am finding most LED ones to be low on light
output and to often have an icy cold color.

This will improve over the next several years.

Or possibly, not. Apparently there's a problem called "droop" when
they try to increase the intensity of LEDs - efficiency drops - and
it's already not quite as good as CFLs on the newer 1 watt and larger
LEDs. Color ... maybe. Price ... maybe a little. But it seems the
technology is currently stuck.

I just got a couple of the 23 watt and 40 watt candelabra base CFLs,
put in one 40 watt - and it was almost too bright, compared to the
incandescent it replaced. That's in a fixture. Haven't put them yet
into the chandelier, we'll see how that goes esthetically.
Fortunately we already removed the dimmer!

J.

On Tue, 20 Oct 2009 11:34:50 -0400, Tony
wrote:

Wayne Boatwright wrote:
On Mon 19 Oct 2009 06:32:25a, Mark Lloyd told us...

On Mon, 19 Oct 2009 00:39:48 GMT, Wayne Boatwright
wrote:

On Sun 18 Oct 2009 11:01:34a, Mark Lloyd told us...

On Sun, 18 Oct 2009 08:27:08 -0400, aemeijers
wrote:
[snip]

Don't know if it is actually bad for the eyes or not, but it does
probably reduce bumped shins when you get up to run to the can during
commercials. I usually just leave the light at the far end of the
kitchen turned on.
And the light makes it harder to accidentally step on a cat. They're
something like the other things you can bump into, but are mobile and
can be found in unexpected places.

I keep a string of green LED holiday lights on all the time.

BTW, some of the lights (some in each series) have gone out over time,
but others are still lit. That's strange.
Actually, not at all strange. Typically these lights are wired in
series,
but the bulbs are designed to fuse the filament together when they burn
out
so that the circuit is still completed.
LEDs don't have filaments, but semiconductor junctions.

Yup, I missed that on first reading. However, there must be something in
the circuit that insures continuity when the led fails.

I don't have one to look at, but there is a good chance they are all
wired parallel and each LED has a resistor built in or added.

It the LEDs are in parallel on 120V, it'd take a big series resistor
and efficiency would be low.

The current consumption of this 70-LED string is about 15mA (.015A).
Since that sounds like the current for one LED, that suggests series.

BTW, I've verified that 35 work on each polarity (testing a new
string).
--
65 days until the winter solstice celebration

Mark Lloyd
http://notstupid.us

"How could you ask me to believe in God when there's
absolutely no evidence that I can see?" -- Jodie Foster

In article , JRStern wrote:
On Mon, 19 Oct 2009 22:55:19 +0000 (UTC), (Don
Klipstein) wrote:

For lamps bright enough for general illumination, such as 40 watt
incandescent equivalent, I am finding most LED ones to be low on light
output and to often have an icy cold color.

This will improve over the next several years.

Or possibly, not. Apparently there's a problem called "droop" when
they try to increase the intensity of LEDs - efficiency drops - and
it's already not quite as good as CFLs on the newer 1 watt and larger
LEDs. Color ... maybe. Price ... maybe a little. But it seems the
technology is currently stuck.

Cree XP-G has definitely more efficiency and apparently less droop than
other white LEDs of similar current ratings. The bare LEDs just became
available at Digi-Key a couple weeks or so ago.

- Don Klipstein )