What is a Solid State Emmiter?

[Peter Cole]

jim beam wrote:
> Peter Cole wrote:

>> If you consider silicon and germanium to be "normal", then no, they
>> don't emit light typically during the process of recombination (e.g.
>> current flow through a p-n junction, the process which causes LED's to
>> emit photons (on a variety of wavelengths).
>
> they emit infrared!!! and the wavelength is very precise as a function
> of energy gap.

No, they do not. You are mistaken. Indirect bandgap materials require a
change in both electron energy and momentum to move from valence to
conduction band. Photon emission doesn't provide the necessary change in
momentum.

 

[jim beam]

Bill wrote:
> jim beam wrote:
>> Friday wrote:
>>>
>>> Just say yes or no.
>>
>> incandescence is not rectification!!! do you understand physics? yes
>> or no.
>
> Some guys will argue with a rock and lose.
> These meaningless arguments are fun to watch, though.
> Bill Baka

incandescence is /still/ not rectification bill.

 

[jim beam]

Peter Cole wrote:
> jim beam wrote:
>> Peter Cole wrote:
>
>>> If you consider silicon and germanium to be "normal", then no, they
>>> don't emit light typically during the process of recombination (e.g.
>>> current flow through a p-n junction, the process which causes LED's
>>> to emit photons (on a variety of wavelengths).
>>
>> they emit infrared!!! and the wavelength is very precise as a
>> function of energy gap.
>
> No, they do not. You are mistaken. Indirect bandgap materials require a
> change in both electron energy and momentum to move from valence to
> conduction band. Photon emission doesn't provide the necessary change in
> momentum.

so why didn't fermi pick up on that then? all my laser science would be
up s-creek without him.

 

[jim beam]

� Schwarz wrote:
> Peter Cole wrote:
>
>> jim beam wrote:
>
>>> that's why i said infra-red. normal semiconductors emit in
>>> infra-red. with chemistry, you can tune the band gap to optical
>>> energies, and thus
>>> get visible emissions. but you don't do that for standard semicons!
>
>> Actually, you're still wrong. Originally you said "all semiconductors
>> emit light", which is wrong.
>>
>> Now you say "normal semiconductors emit in the infra-red". I'm not at
>> all sure what you mean by "normal". Infra-red light is still light
>> (photons).
>>
>> If you consider silicon and germanium to be "normal", then no, they
>> don't emit light typically during the process of recombination (e.g.
>> current flow through a p-n junction, the process which causes LED's to
>> emit photons (on a variety of wavelengths).
>>
>> In silicon and other "indirect bandgap" materials, the energy of
>> recombination is released via phonons rather than photons.
>
> Sorry Peter, but with all the BS jb writes in this thread he is
> obviously a hopeless case. Teaching an empty bottle calculus will be
> easier than correcting all this nonsense. It hurts to read it, so I
> won't go through all of it.
> The only thing he is right about is that all semiconductor devices are
> at ambient temperature when not in use and heat up during operation. So
> they emit black body radiation. To make use of this effect for lighting
> applications Edison commercialized the light bulb. A much more
> practical device than silicon above the melting temperature for
> lighting up your home place
>
> Günther

eh? anything above 0K emits black body radiation!

 

[RBrickston]

In article <[email protected]>,
[email protected] says...
> Bill wrote:
<mercy snip>

> >
> > There is also a link to a PDF file to show the wavelengths and
> > chemistry. This manufacturer, whom I have never heard of before, does
> > not use a simple LED to energize a flourescent to get white, as some
> > have suggested, but puts out a spectrum that is heavy on the blue end.
> >
> > I could post more from Jameco, Mouser, Allied, etc....., until people
> > got sick of the subject.
> >
> > Bill Baka
>
>
> but that's the point! the larger the band gap, the larger the voltage
> required! you change chemistry to change the band gap and voltage
> varies accordingly!
>
Baka's post just proves that he's a regurgitator of information found on
the web; and he's not very good at it. Bottom line: not a wisp of
original thought, unless he's making something up about himself.

 

[[email protected]]

On Jun 18, 6:16 am, jim beam <[email protected]> wrote:
> Peter Cole wrote:
> > jim beam wrote:
> >> Peter Cole wrote:
>
> >>> If you consider silicon and germanium to be "normal", then no, they
> >>> don't emit light typically during the process of recombination (e.g.
> >>> current flow through a p-n junction, the process which causes LED's
> >>> to emit photons (on a variety of wavelengths).
>
> >> they emit infrared!!! and the wavelength is very precise as a
> >> function of energy gap.
>
> > No, they do not. You are mistaken. Indirect bandgap materials require a
> > change in both electron energy and momentum to move from valence to
> > conduction band. Photon emission doesn't provide the necessary change in
> > momentum.
>
> so why didn't fermi pick up on that then? all my laser science would be
> up s-creek without him.

What are you talking about? The difference Peter
mentioned (direct/indirect gap materials) is completely
consistent with everything we know about Fermi
statistics. In indirect gap materials, photon
absorption or emission is accompanied by a phonon
(That's a sound wave in the material, for those
of you not used to the jargon.) Because it is a
two-step process, the energy of the photon will not
be precise. Also the light absorption and emission
is much less efficient. This is why LEDs and
photodiodes are made out of special materials,
not J. Random Semiconductor.

See Figure 4.6.1 in
http://ece-www.colorado.edu/~bart/book/book/chapter4/ch4_6.htm#4_6_1

It's true that all semiconductors also give off
heat in operation, which means they are emitting
thermal infrared radiation, but this is not the
same process as the one that makes LEDs and laser
diodes work. (LEDs and laser diodes emit both
visible or near-IR radiation in a relatively narrow
wavelength range, and the usual heat radiation.)

Ben

 

[Peter Cole]

jim beam wrote:
> Peter Cole wrote:
>> jim beam wrote:
>>> Peter Cole wrote:
>>
>>>> If you consider silicon and germanium to be "normal", then no, they
>>>> don't emit light typically during the process of recombination (e.g.
>>>> current flow through a p-n junction, the process which causes LED's
>>>> to emit photons (on a variety of wavelengths).
>>>
>>> they emit infrared!!! and the wavelength is very precise as a
>>> function of energy gap.
>>
>> No, they do not. You are mistaken. Indirect bandgap materials require
>> a change in both electron energy and momentum to move from valence to
>> conduction band. Photon emission doesn't provide the necessary change
>> in momentum.
>
> so why didn't fermi pick up on that then? all my laser science would be
> up s-creek without him.

This was originally published in 1952 by Shockley and Reid, and in the
same year (independently) by Hall. You're just a little out of date.

 

[=?ISO-8859-1?Q?G=FCnther?= Schwarz]

jim beam wrote:

> � Schwarz wrote:
>> Peter Cole wrote:
>>
>>> jim beam wrote:

>>> In silicon and other "indirect bandgap" materials, the energy of
>>> recombination is released via phonons rather than photons.
>>
>> Sorry Peter, but with all the BS jb writes in this thread he is
>> obviously a hopeless case.

>> The only thing he is right about is that all semiconductor devices
>> are at ambient temperature when not in use and heat up during
>> operation. So they emit black body radiation.

> eh? anything above 0K emits black body radiation!

Bingo, you've got my point. As Peter already explained with much more
patience than I have a silicon based device is as interesting as a cup
of coffee as far as the emission of electromagnetic radiation is
concerned.
And just in case some experts want to jump in here: There are effects
like transitions in core levels which involve the emissions of photons.
There also have been serious and ongoing efforts in building a silicon
based laser, IIRC mostly by exploiting finite size effects to shape the
band structure. Up to now with no convincing success. I consider none
of this to be relevant for this discussion.

Günther

 

[Bill]

jim beam wrote:
> Bill wrote:
>> jim beam wrote:
>>> Friday wrote:
>>>>
>>>> Just say yes or no.
>>>
>>> incandescence is not rectification!!! do you understand physics?
>>> yes or no.
>>
>> Some guys will argue with a rock and lose.
>> These meaningless arguments are fun to watch, though.
>> Bill Baka
>
> incandescence is /still/ not rectification bill.

Why bother? Incandescence is just light emitted from a variable resistor
filament. The low resistance at turn on is what makes the weakest point
go Supernova when you turn on a bulb that is ready to go out with a
bang, err, flash.
IF the bulb was a vacuum and IF there was a plate (anode) you could call
it a very bright rectifier, but then you would have only a very
primitive tube with no indirectly heated cathode.
Bill Baka

 

[Bill]

jim beam wrote:
> Bill wrote:
>> And here is a white at 3.5 volts.
>> http://www.jameco.com/webapp/wcs/st...toreId=10001&catalogId=10001&productId=183231
>>
>>
>> There is also a link to a PDF file to show the wavelengths and
>> chemistry. This manufacturer, whom I have never heard of before, does
>> not use a simple LED to energize a flourescent to get white, as some
>> have suggested, but puts out a spectrum that is heavy on the blue end.
>>
>> I could post more from Jameco, Mouser, Allied, etc....., until people
>> got sick of the subject.
>>
>> Bill Baka
>
>
> but that's the point! the larger the band gap, the larger the voltage
> required! you change chemistry to change the band gap and voltage
> varies accordingly!

I know that, but part of my point was that the number of chemistries is
growing as people search for real 'white' light, and not the blueish
tint that was shown in the pdf I pointed to, or a super efficient and
bright chemistry that will surpass all previous attempts. All of the
traffic lights in my somewhat backwater town have gone to single
wavelength red, yellow, green that can be seen even in bright sunlight.
I have only seen one light with one burned out LED in the green and they
don't see fit to replace it since it has been like that for over 2 years.
Mainstream LEDs emit in one very tight wavelength, kind of the light
version of a radio crystal.
Even I don't want to try to calculate the band gaps that are used all
over the map, like the Jameco part I referred to. That one tries to be
white and the spectrum is not a spike at one wavelength but a wide blue
tapering off on the red end of things. I had to download Chinese fonts
for my Acrobat just to see the whole data sheet, and I only want to
spend so much 'unpaid' time on research.
Pay me and I will make a spreadsheet of every LED ever made and the band
gaps of all the possible materials.
There are probably only a handful of people who care what makes the
light as long as it works.
I'm one since I have a Cat-Eye 5 LED setup with through hole white LEDs
and I might want to upgrade it if I can find some better white LEDs.
I was also thinking of building a miniature boost/buck universal
converter to drive the LEDs at whatever brightness I wanted to dial in
with an old fashioned pot. 3.3 volts on the LEDs, 4.8 volts from my NiMH
batteries, and 6 volts from Alkalines. I wouldn't mind sucking the
Alkalines for their last gasp, but the NiMH rechargeables might not like
that very much.
OK, enough electronic stuff.
Bill Baka

 

[jim beam]

Bill wrote:
> jim beam wrote:
>> Bill wrote:
>>> jim beam wrote:
>>>> Friday wrote:
>>>>>
>>>>> Just say yes or no.
>>>>
>>>> incandescence is not rectification!!! do you understand physics?
>>>> yes or no.
>>>
>>> Some guys will argue with a rock and lose.
>>> These meaningless arguments are fun to watch, though.
>>> Bill Baka
>>
>> incandescence is /still/ not rectification bill.
>
> Why bother? Incandescence is just light emitted from a variable resistor
> filament. The low resistance at turn on is what makes the weakest point
> go Supernova when you turn on a bulb that is ready to go out with a
> bang, err, flash.
> IF the bulb was a vacuum and IF there was a plate (anode) you could call
> it a very bright rectifier, but then you would have only a very
> primitive tube with no indirectly heated cathode.
> Bill Baka

but there's still no similarity in physics bill. just like fission and
combustion both produce heat, but their physics are totally different.

 

[jim beam]

[email protected] wrote:
> On Jun 18, 6:16 am, jim beam <[email protected]> wrote:
>> Peter Cole wrote:
>>> jim beam wrote:
>>>> Peter Cole wrote:
>>>>> If you consider silicon and germanium to be "normal", then no, they
>>>>> don't emit light typically during the process of recombination (e.g.
>>>>> current flow through a p-n junction, the process which causes LED's
>>>>> to emit photons (on a variety of wavelengths).
>>>> they emit infrared!!! and the wavelength is very precise as a
>>>> function of energy gap.
>>> No, they do not. You are mistaken. Indirect bandgap materials require a
>>> change in both electron energy and momentum to move from valence to
>>> conduction band. Photon emission doesn't provide the necessary change in
>>> momentum.
>> so why didn't fermi pick up on that then? all my laser science would be
>> up s-creek without him.
>
> What are you talking about? The difference Peter
> mentioned (direct/indirect gap materials) is completely
> consistent with everything we know about Fermi
> statistics. In indirect gap materials, photon
> absorption or emission is accompanied by a phonon
> (That's a sound wave in the material, for those
> of you not used to the jargon.) Because it is a
> two-step process, the energy of the photon will not
> be precise. Also the light absorption and emission
> is much less efficient. This is why LEDs and
> photodiodes are made out of special materials,
> not J. Random Semiconductor.
>
> See Figure 4.6.1 in
> http://ece-www.colorado.edu/~bart/book/book/chapter4/ch4_6.htm#4_6_1
>
> It's true that all semiconductors also give off
> heat in operation, which means they are emitting
> thermal infrared radiation, but this is not the
> same process as the one that makes LEDs and laser
> diodes work. (LEDs and laser diodes emit both
> visible or near-IR radiation in a relatively narrow
> wavelength range, and the usual heat radiation.)
>

but that emission is a function of the band gap! the narrower the gap,
the longer the wavelength. "normal" semicons just have a longer wavelength.

back in the days of glass-encased germanium semicons, you could scrape
off the black paint and use them as emitters & receivers.

 

[jim beam]

� Schwarz wrote:
> jim beam wrote:
>
>> � Schwarz wrote:
>>> Peter Cole wrote:
>>>
>>>> jim beam wrote:
>
>>>> In silicon and other "indirect bandgap" materials, the energy of
>>>> recombination is released via phonons rather than photons.
>>> Sorry Peter, but with all the BS jb writes in this thread he is
>>> obviously a hopeless case.
>
>>> The only thing he is right about is that all semiconductor devices
>>> are at ambient temperature when not in use and heat up during
>>> operation. So they emit black body radiation.
>
>> eh? anything above 0K emits black body radiation!
>
> Bingo, you've got my point. As Peter already explained with much more
> patience than I have a silicon based device is as interesting as a cup
> of coffee as far as the emission of electromagnetic radiation is
> concerned.
> And just in case some experts want to jump in here: There are effects
> like transitions in core levels which involve the emissions of photons.

that's what i keep trying to have you guys understand!!!

> There also have been serious and ongoing efforts in building a silicon
> based laser, IIRC mostly by exploiting finite size effects to shape the
> band structure. Up to now with no convincing success.

eh?

http://www.mtmi.vu.lt/pfk/funkc_dariniai/diod/led.htm

and dopant is not substrate.

> I consider none
> of this to be relevant for this discussion.
>
> Günther

 

[jim beam]

Bill wrote:
> jim beam wrote:
>> Bill wrote:
>>> And here is a white at 3.5 volts.
>>> http://www.jameco.com/webapp/wcs/st...toreId=10001&catalogId=10001&productId=183231
>>>
>>>
>>> There is also a link to a PDF file to show the wavelengths and
>>> chemistry. This manufacturer, whom I have never heard of before, does
>>> not use a simple LED to energize a flourescent to get white, as some
>>> have suggested, but puts out a spectrum that is heavy on the blue end.
>>>
>>> I could post more from Jameco, Mouser, Allied, etc....., until people
>>> got sick of the subject.
>>>
>>> Bill Baka
>>
>>
>> but that's the point! the larger the band gap, the larger the voltage
>> required! you change chemistry to change the band gap and voltage
>> varies accordingly!
>
> I know that, but part of my point was that the number of chemistries is
> growing as people search for real 'white' light, and not the blueish
> tint that was shown in the pdf I pointed to, or a super efficient and
> bright chemistry that will surpass all previous attempts. All of the
> traffic lights in my somewhat backwater town have gone to single
> wavelength red, yellow, green that can be seen even in bright sunlight.
> I have only seen one light with one burned out LED in the green and they
> don't see fit to replace it since it has been like that for over 2 years.
> Mainstream LEDs emit in one very tight wavelength, kind of the light
> version of a radio crystal.
> Even I don't want to try to calculate the band gaps that are used all
> over the map, like the Jameco part I referred to. That one tries to be
> white and the spectrum is not a spike at one wavelength but a wide blue
> tapering off on the red end of things. I had to download Chinese fonts
> for my Acrobat just to see the whole data sheet, and I only want to
> spend so much 'unpaid' time on research.
> Pay me and I will make a spreadsheet of every LED ever made and the band
> gaps of all the possible materials.

so what? doesn't mean a thing if you don't understand what you're
looking at!


> There are probably only a handful of people who care what makes the
> light as long as it works.
> I'm one since I have a Cat-Eye 5 LED setup with through hole white LEDs
> and I might want to upgrade it if I can find some better white LEDs.
> I was also thinking of building a miniature boost/buck universal
> converter to drive the LEDs at whatever brightness I wanted to dial in
> with an old fashioned pot. 3.3 volts on the LEDs, 4.8 volts from my NiMH
> batteries, and 6 volts from Alkalines. I wouldn't mind sucking the
> Alkalines for their last gasp, but the NiMH rechargeables might not like
> that very much.

irrelevant.


> OK, enough electronic stuff.

please bill, please.

 

[Bill]

jim beam wrote:
>
> back in the days of glass-encased germanium semicons, you could scrape
> off the black paint and use them as emitters & receivers.

Heh.
I have some in a drawer or box somewhere with clear tops. Like a 1955
photo-transistor. I have 2N107 and 2N170 pairs, along with some CK722's
and a lot of old weird stuff that I either saved for 50+ years or found
on Ebay.
Lots of 1N34 diodes, too.
I still preferred cat whiskers on Gillette blue blades oxide coating.
Bill (showing my age) Baka

 

[Bill]

jim beam wrote:
> Bill wrote:
>> Why bother? Incandescence is just light emitted from a variable
>> resistor filament. The low resistance at turn on is what makes the
>> weakest point go Supernova when you turn on a bulb that is ready to go
>> out with a bang, err, flash.
>> IF the bulb was a vacuum and IF there was a plate (anode) you could
>> call it a very bright rectifier, but then you would have only a very
>> primitive tube with no indirectly heated cathode.
>> Bill Baka
>
> but there's still no similarity in physics bill. just like fission and
> combustion both produce heat, but their physics are totally different.

I know that, so I think I got mis-quoted somewhere along the line or at
least mis-understood. This is bicycle tech, not physics tech, so why go
all hyper scientific? At least I didn't say "Thermionic valve".
LEDs have electrons jumping all over the place to make light while
conducting electricity and their chemical makeup influences the actual
wavelength of the light emitted, but there are so many varieties that I
would actually have to read up on it again. The one thing that does seem
to be constant is that some LEDs produce 600 nm exactly, while another
will produce 604 nm exactly, regardless of current, just bright or dim.
That is physics. Incandescence is dependent on temperature so hotter
equals shorter wavelengths. This explains why Quartz-Halogens that burn
so hot look bluer than normal headlights.
I get it, but don't want to make a big deal on the bicycle groups.
Bill Baka

 

[Bill]

jim beam wrote:
> � Schwarz wrote:
>> There also have been serious and ongoing efforts in building a silicon
>> based laser, IIRC mostly by exploiting finite size effects to shape the
>> band structure. Up to now with no convincing success.
>
> eh?
>
> http://www.mtmi.vu.lt/pfk/funkc_dariniai/diod/led.htm
>
> and dopant is not substrate.
>
I snipped somebody but....
There was a semi-based laser built into a TO-3 power transistor shell
about ten years back but I never did anything more than look at the data
sheet, so they could be real (or not). In 2001 I was involved in
military work for the UAVs that have become so popular and the targeting
and range finding laser used about 400 volts so I am guessing it wasn't
a diode.
Beyond that I claim ignorance since I am not working with them now.
Bill Baka

 

[jim beam]

Bill wrote:
> jim beam wrote:
>> Bill wrote:
>>> Why bother? Incandescence is just light emitted from a variable
>>> resistor filament. The low resistance at turn on is what makes the
>>> weakest point go Supernova when you turn on a bulb that is ready to
>>> go out with a bang, err, flash.
>>> IF the bulb was a vacuum and IF there was a plate (anode) you could
>>> call it a very bright rectifier, but then you would have only a very
>>> primitive tube with no indirectly heated cathode.
>>> Bill Baka
>>
>> but there's still no similarity in physics bill. just like fission
>> and combustion both produce heat, but their physics are totally
>> different.
>
> I know that, so I think I got mis-quoted somewhere along the line or at
> least mis-understood. This is bicycle tech, not physics tech, so why go
> all hyper scientific? At least I didn't say "Thermionic valve".
> LEDs have electrons jumping all over the place to make light while
> conducting electricity and their chemical makeup influences the actual
> wavelength of the light emitted, but there are so many varieties that I
> would actually have to read up on it again. The one thing that does seem
> to be constant is that some LEDs produce 600 nm exactly, while another
> will produce 604 nm exactly, regardless of current, just bright or dim.
> That is physics. Incandescence is dependent on temperature so hotter
> equals shorter wavelengths. This explains why Quartz-Halogens that burn
> so hot look bluer than normal headlights.
> I get it, but don't want to make a big deal on the bicycle groups.
> Bill Baka

you don't get it because you were trying to equate incandescence with
what is essentially laser behavior. trying to fudge by saying that
because it's only bike tech, it's not going to get a proper explanation
is disgraceful.

 

[Bill]

jim beam wrote:
> Bill wrote:
>> jim beam wrote:
>>> Bill wrote:
>>>> And here is a white at 3.5 volts.
>>>> http://www.jameco.com/webapp/wcs/st...toreId=10001&catalogId=10001&productId=183231
>>>>
>>>>
>>>> There is also a link to a PDF file to show the wavelengths and
>>>> chemistry. This manufacturer, whom I have never heard of before,
>>>> does not use a simple LED to energize a flourescent to get white, as
>>>> some have suggested, but puts out a spectrum that is heavy on the
>>>> blue end.
>>>>
>>>> I could post more from Jameco, Mouser, Allied, etc....., until
>>>> people got sick of the subject.
>>>>
>>>> Bill Baka
>>>
>>>
>>> but that's the point! the larger the band gap, the larger the
>>> voltage required! you change chemistry to change the band gap and
>>> voltage varies accordingly!
>>
>> I know that, but part of my point was that the number of chemistries
>> is growing as people search for real 'white' light, and not the
>> blueish tint that was shown in the pdf I pointed to, or a super
>> efficient and bright chemistry that will surpass all previous
>> attempts. All of the traffic lights in my somewhat backwater town have
>> gone to single wavelength red, yellow, green that can be seen even in
>> bright sunlight.
>> I have only seen one light with one burned out LED in the green and
>> they don't see fit to replace it since it has been like that for over
>> 2 years.
>> Mainstream LEDs emit in one very tight wavelength, kind of the light
>> version of a radio crystal.
>> Even I don't want to try to calculate the band gaps that are used all
>> over the map, like the Jameco part I referred to. That one tries to be
>> white and the spectrum is not a spike at one wavelength but a wide
>> blue tapering off on the red end of things. I had to download Chinese
>> fonts for my Acrobat just to see the whole data sheet, and I only want
>> to spend so much 'unpaid' time on research.
>> Pay me and I will make a spreadsheet of every LED ever made and the
>> band gaps of all the possible materials.
>
> so what? doesn't mean a thing if you don't understand what you're
> looking at!

I found out long ago that you can't learn everything and anyone who
claims to is either an idiot or lier. I'm an E.E. who just uses the
parts so I don't need to know all the band gaps. I do get paid for
designing circuits that use these parts and I am very money motivated.
>
>
>> There are probably only a handful of people who care what makes the
>> light as long as it works.
>> I'm one since I have a Cat-Eye 5 LED setup with through hole white
>> LEDs and I might want to upgrade it if I can find some better white LEDs.
>> I was also thinking of building a miniature boost/buck universal
>> converter to drive the LEDs at whatever brightness I wanted to dial in
>> with an old fashioned pot. 3.3 volts on the LEDs, 4.8 volts from my
>> NiMH batteries, and 6 volts from Alkalines. I wouldn't mind sucking
>> the Alkalines for their last gasp, but the NiMH rechargeables might
>> not like that very much.
>
> irrelevant.

Only if you want to buy new rechargeables every week. Kind of defeats
the purpose. I haven't seen any bicycle headlights that claimed to have
an active circuit for maximizing either battery life or brightness or
even just a level adjust other than a high/low resistor switch.
>
>
>> OK, enough electronic stuff.
>
> please bill, please.
>
>
How about enough physics stuff from you then?
Bill Baka

 

[Bill]

jim beam wrote:
> Bill wrote:
>> jim beam wrote:
>>> Bill wrote:
>>>> Why bother? Incandescence is just light emitted from a variable
>>>> resistor filament. The low resistance at turn on is what makes the
>>>> weakest point go Supernova when you turn on a bulb that is ready to
>>>> go out with a bang, err, flash.
>>>> IF the bulb was a vacuum and IF there was a plate (anode) you could
>>>> call it a very bright rectifier, but then you would have only a very
>>>> primitive tube with no indirectly heated cathode.
>>>> Bill Baka
>>>
>>> but there's still no similarity in physics bill. just like fission
>>> and combustion both produce heat, but their physics are totally
>>> different.
>>
>> I know that, so I think I got mis-quoted somewhere along the line or
>> at least mis-understood. This is bicycle tech, not physics tech, so
>> why go all hyper scientific? At least I didn't say "Thermionic valve".
>> LEDs have electrons jumping all over the place to make light while
>> conducting electricity and their chemical makeup influences the actual
>> wavelength of the light emitted, but there are so many varieties that
>> I would actually have to read up on it again. The one thing that does
>> seem to be constant is that some LEDs produce 600 nm exactly, while
>> another will produce 604 nm exactly, regardless of current, just
>> bright or dim.
>> That is physics. Incandescence is dependent on temperature so hotter
>> equals shorter wavelengths. This explains why Quartz-Halogens that
>> burn so hot look bluer than normal headlights.
>> I get it, but don't want to make a big deal on the bicycle groups.
>> Bill Baka
>
> you don't get it because you were trying to equate incandescence with
> what is essentially laser behavior. trying to fudge by saying that
> because it's only bike tech, it's not going to get a proper explanation
> is disgraceful.

I got it the first time. I am not always totally stick up my ass
serious. Fission and fusion both produce heat and light, but by
different means. Am I going there?
Hell no.
I'm going to watch the **** tube now.
Bill Baka