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?

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...

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.

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.

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?

But there is a lot of development going on. With progress in color
and lumen output being made at a good rate.

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

Excellent news - thanks.

BJ