On May 22, 8:27 am, "Mark S. Holden" wrote:
D Peter Maus wrote:

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. ]

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

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.

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.

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.

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.

I'm thinking electroluminescent lights may end up taking over for home
lighting, though it'll look different from what we're used to.

http://www.electronicproducts.com/Sh...=hlap05.jul200...


But for now, it's still a little expensive.

A problem with LEDs is they project light on a relatively narrow beam.
A normal light bulb is omni-directional.

One way of dealing with the color balance of LEDs is you can mix in some
red ones with the white ones, but again, the narrow beam from an LED
makes it tougher to get even light with even color balance.

I've done some LED lighting at my observatory, and at home. At the
observatory, we put a recessed red LED every 4" in the molding for the
dome trim ring so they tend to light the walls and floor. We also made
an LED lectern light for star charts.

At home, I've got white ones that illuminate a stairwell, and I've got
some mounted on the top of a beam that are aimed at the cathedral
ceiling in my kitchen for background lighting.

I use regulated DC power supplies so they can dim quietly, though with
my antenna a couple hundred feet away, I doubt it would matter.- Hide quoted text -

- Show quoted text -

LED Christmas Lights - They Last Forever + Plus the
LEDs use very little Power so you can put-up as many
as you want without causing a Power problem. Makes
your whole House shine and glow like a Constellation. ~ RHF