bpnjensen wrote:
On May 21, 2:29 pm, D Peter Maus wrote:
bpnjensen wrote:

I agree with Joe and Brenda about LEDs, and I cannot believe that the
powers that be have not jumped onto the bandwagon with these things.
Their potential is enormous. They are fairly cheap, last nearly
forever (maybe that's why?) and use a shred of the energy used by any
other viable light source.
Bruce Jensen
Actually, they are, in a way, getting in on the LED wagon. Here in
The Windy, as well as in a good number of venues I've visited in
Wisconsin, the traffic lights have been changed from incandescent, to
LED arrays. They're very harsh to look at without the original color
filters used with the incandescents because the colors are pure, and the
viewing angle is narrow...putting the output of nearly 100 high output
LED's into a narrow beam. Small matter. Slap the filter over the LED's
and you've got a mellower color output with no diminution in brightness. ]

Good to hear.

They'll last. Lower maintenance costs. Total energy for the traffic
system is reduced, but not by as much as you might think.

How so?


You've got 100 elements putting out as much light as a single
incandescent. One two, or ten superbright LED's will save you a lot of
energy. 100...not so much.

But still, there's less heating, there IS an energy saving, and
there's far less maintenance involved.

That, alone, is worth the investment.

Hell, it's the reason I've pulled all the incandescents out of my
stereo hardware and dropped in LED's. Someunits, like my Mac C-26 look
different, because of the face was created for incandescent light, with
it's higher red output, to provide both the green filters and the red
with output using the same bulbs...but it's a small difference.

Units using incandescents for the warmth of the parchment look on
meters don't do as well with LED's, but as manufacturers warm up the
output on their devices, that will change.

Most units, however, like my McKay Dymek AM-5 with, what 8
lamps...when converted to LED's (and drop-in replacements, at that) Look
pretty nice.

No more burning of plastic diffusers. No more opening the damned
things up ever few months to replace incandescents.



But they depending on installation and operating parameters, produce a hellaceous amount of RF noise. The LED arrays in my area cast RFI shadows as far inland as my house.

That stinks - would this be true of ousehold LEDs too? Probably...

Depends on the power source. I've noticed it more on AC/DC LED
drop-ins than DC LED's alone. But even that can be abated with a bit of
capacitance across the junction, and across the diodes of the power source.



It can be overcome. Whether it will is a matter of some debate.

LED's are particularly well suited for this application because the
color purity is high, and consistent.

Most applications for white LED's have limited applicable product due
to the generally more blue nature of white LED light.

LED's are also finding their way into the marker, tail and brake
lights of many models of car. With varying results depending on the
purity of the voltage applied. Also easily overcome. And manufacturers
are motivated.

I almost think my headlights are LEDs - they are very blue, and won't
run down the battery.


Not likely. At least not at this stage. There simply isn't enough
lumen output in LED technology, yet.

Likely, they're discharge lamps. Higher efficiency, and bluer
than incandescents.



All of the flashlights in my house, my flight bag, tool and remote
kits, and vehicle glove boxes are multi LED models.

Varying color temperature makes some better than others.

The red ones are killer for astronomy at night, and can be varied in
brightness to suit.

And they're finding their way into maplights on aircraft for that
reason.




There are some track lighting systems that are retrofittable to LED
projectors. For more than $40 a pop. With dramatic long term savings.
Casual lighting, like table lamps are still not practical for LED
lighting, and the color temperatures of many white LED's are still too
blue to be practical for most applications.

Could filters solve this problem?

Not without considerable loss in output. A filter can only
subtract from the input. Low red output is problem. A filter can only
decrease the higher frequencies to bring the red back into balance. With
as little red as there is in the output of a white LED, a you'd be
defeating your own purpose by attempting to correct color balance with
filtration.

But, again, manufacturers are working on this. The last
shipment of LED flashlights I got were a lot warmer than the previous,
so it's not like it can't happen, in time. This is still new technology
for general application. A little patience, and there will be some
serious improvements in the pipeline.




Nearly every wholesaler of light bulbs for general lighting, now,
offers some LED product for home and business lighting applications.

Excellent news - thanks.


I check about once a month for new purveyors of LED drop-ins.
More every time. SuperbrightLEDs.com is a good source for some types.
Digi-key is carrying more LED products for general use.

Do a general websearch. Be amazed.

It IS, indeed, excellent news.