John Smith wrote:
"I have a high power LED flashlight. 5 superbright LED`s in the
element...it is bright. If I bring it near an AM radio, I lose all
reception."

I have a Timex Indeglow watch with a fairly dim dial illumination when I
depress the dialstem. It wipes out radio reception too. I suspect that
solidstate diodes are noidy devices. They are efficient though as the
light is not accompanied with much heat. As for diode noise, zeners are
often used as noise generators, are they not?

There are various ways to get an atom`s orbital electrons to move to a
higher energy level. You can throw a stick on a fire or aim an electron
beam on a CRT phospher.. From a laser, we`re looking for coherent
radiation.

Best regards, Richard Harrison, KB5WZI

There are various ways to get an atom`s orbital electrons to move to a
higher energy level...

Your sentence, above, triggered some questions I have had in the back of my
mind...
In older lasers, they were referred to as "pumps", and indeed the light
souce always seemed to be "strobed."
I wonder if a LED is not "strobed", either occuring as a natural property of
the LED itself, or circuitry incorporated on the LED chip, itself, which
"strobes" it?
Mainly, I have considered the above in regards to wondering about giant
sheets of polished aluminum, focusing the sun on a laser rod (or gas tube)
and beaming the energy down to the planet (as has been proposed by others),
and if someway to "strobe" the lightsouce would have to be devised? And,
this in regards to the "pump"-ing action I have heard referenced... as, if I
understand it correctly, you must kick (pump) the electrons up a level, then
let them oscillate back to their original state, then kick-pump them
again... as the actual light is generated by the electrons shifting states,
and NOT just the fact that they are at another energy level...
It seemed to me the answer would be easy to find, from a search of the
web... I was not successful...
Your thoughts/knowledge?

Regards,
John

On Fri, 29 Apr 2005 00:37:12 -0700, "John Smith"
wrote:

I wonder if a LED is not "strobed", either occuring as a natural property of
the LED itself, or circuitry incorporated on the LED chip, itself, which
"strobes" it?

Hi Brett,

The voltage supplied to the LED elevates the electron out of one
orbital to the conduction band. When it falls back, a photon is
emitted. The wavelength of the emitted photon is the path length the
electron follows spiraling from one orbital to the other (DeBroglie
wave).

There are no lasers that are pumped in a cyclic sense except those
that emit a pulse like the old CO2 UV lasers. I had a buddy who built
one that used plate glass and aluminum foil to build the high voltage
charge used to excite the gas to lasing (you still need an optically
resonant chamber to build the intensity).

This design, from the pages of Scientific American's Amateur Scientist
column exhibited a very high peak power because of the extremely short
pulse duration. His knowing this instilled the caution to aim it out
the window into free space for its inaugural firing. When he pulsed
it he cracked the window. Window glass is not perfectly transmissive,
and the high peak power and short interval conspired to create a very
hot dislocality - the glass couldn't shed the heat fast enough and it
cracked.

73's
Richard Clark, KB7QHC

Richard Clark wrote:
The wavelength of the emitted photon is the path length the
electron follows spiraling from one orbital to the other (DeBroglie
wave).

Actually, I think it's more of a quantum thing - a function of the band
gap energy E, which is equal to hv (read h nu) where h is Planck's
constant. Wavelenth is of course related to v by a constant, c (speed
of light). Lambda = c/v. So wavelength = hc/E. If it was a DeBroglie
thing, wavelength would depend on the momentum of the particle as h/p.
The band gap energy is not determined by the energy carried by the
particle, (or by the length of its path), but by the atomic nature of
the material comprising the LED, and the difference in energy between
the conduction band and the valence band of that material.

ac6xg

Probably... and those of us who have taken calculus and spent years of our
life closely working with mathematicians (or, those truck drivers who had an
uncanny interest in math and have studied it in great detail--just for
self-satisfaction) grasp the general concept--however, a wise-intelligent
individual tries to express the complex in terms where the greatest numbers
can make use of the knowledge, especially, when debates/arguments and proofs
are offered in such a public forum as usenet--here, your explaination
fails... I would venture that to most--this looks like nothing more than you
stroking your ego...

Regards,
John

On Fri, 29 Apr 2005 12:47:18 -0700, Jim Kelley
wrote:
Richard Clark wrote:
The wavelength of the emitted photon is the path length the
electron follows spiraling from one orbital to the other (DeBroglie
wave).

Actually, I think it's more of a quantum thing

Hi Jim,

The De Broglie [my spelling error] wave is a quantum thing.

In fact Louis de Brolie presented in 1924 that MATTER was composed of
discrete wavelengths (quanta). His was the identical treatment of
Einstein's proposition with light. Both he and Einstein had revealed
the duality of nature, and De Broglie's assertions were proven in
1927. The effect of his work left Schrodinger with the starting point
for his development of quantum mechanics.

73's
Richard Clark, KB7QHC

Damn...
That is all silly...
But, hey, does that light bulb in the refrig really go out when I close the
door? Or, is it too subject to the quantum laws, and it only depends on an
observer? grin

Regards,
John

On Fri, 29 Apr 2005 14:30:01 -0700, "John Smith"
wrote:
But, hey, does that light bulb in the refrig really go out when I close the
door? Or, is it too subject to the quantum laws
Only if Schrodinger's cat was inside to watch.

Indiglo uses an electroluminescent panel that's powered by an inverter.
It takes something like 100V to light it. It's probably the inverter
that's causing the RFI.

Geneb wrote:
"Indiglo uses an electroluminescent panel that`s powered by an
inverter."

The whine says you`re right.

Best regards, Richard Harrison, KB5WZI