On Oct 21, 2009, at 12:54 PM, [email protected] wrote:
In reply to Horace Heffner's message of Tue, 20 Oct 2009 18:37:42
-0800:
Hi,
This appears to be the same technology used in CRT TV sets. I
wonder what the
energy of the electrons is, and whether or not x-rays are produced?
I didn't see any information regarding that. It must be a pretty low
voltage because otherwise the efficiency would be much lower. The
bulbs are supposedly comparable to CFLs in efficiency. Due to the
quantum nature of light, I think any excess energy above that
required to step up the electrons to the energy levels needed would
be wasted, and that should be well under 20 eV. Better to put the
power toward a higher current than any voltage much above the
threshold I think. The advantage over ordinary CRTs is that the
fluorescent time can be much longer - no need for fast phosphors,
fast travel times, or narrow focused beams. In fact, a low voltage
would assist in getting a wide dispersion of the beam due to more
time for mutual Coulomb repulsion of electrons in the beam to occur.
I'm very curious as to whether any rare commodities are used in the
bulbs, what is used for an emitter and for phsphors, and thus the
exposure to the Chinese commodities grab. A filament emitter would
be somewhat of an energy hog and reduce bulb life. The bulb life is
supposedly comperable to CFLs as well. I don't understand why LED
supposedly lights take so much power, unless it is for energy
conversion circuitry. I think some of the big new Wal-Mart store LED
lighting installations use a centralized DC power supply, and DC
network, driven by both AC and by photovoltaics, so that may cut down
on energy lost to heat by their LED bulb replacements. I accidentally
left a two AA battery LED flashlight on and was amazed to see it
running just fine about 20 hours later. It did not produce noticeable
heat.
Best regards,
Horace Heffner
http://www.mtaonline.net/~hheffner/
