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Long life lights

J

JosephKK

Jan 1, 1970
0
I've got a problem. I happen to carry the distinction of being the one
responsible for changing lights. Much as that's a problem in itself, the
biggest problem is.....the front porch light (surprisingly, it's not a
stairway light, eh?), which happens to be a hanging, upside-down, enclosed
fixture. And they put two screws in the thing, so it's almost impossible
for a single person to replace the bulb thus inserted. Really quite
remarkable how no one thought of this.

Besides modifying it, which I may consider because it's just that bad, in
the mean time I need something that'll last. We've already tried the "ten
gajillion hour" CFLs, which died in all of, you know it, three months. I'm
guessing something high voltage (130V+?) and incandescent. Any
recommendations?

Tim

They are still expensive as heck, but you can get LED lamps. Perhaps
below US$50 each for 100W equivalent, but always over 30,000 power on
hours life and some (more expensive) are rated at over 100,000 hours
power on.
 
E

Eeyore

Jan 1, 1970
0
Tim said:
We've already tried the "ten
gajillion hour" CFLs, which died in all of, you know it, three months.

What brand was it ? The highest rating I've seen is 15,000 hours and I reckon
it did more.

I trust only Philips and Osram (may be linked to Sylvania in the US). I've had
ZERO trouble with them but did have trouble with GE.

The important thinmg is that they're not switched on and off every couple of
minutes.

Graham
 
T

Tim Williams

Jan 1, 1970
0
Eeyore said:
What brand was it ?
...
I've had ZERO trouble with them but did have trouble with GE.

Wouldn't you know it, these are GE as well.

Can they really sell a product that lasts maybe a year and claim it has,
idunno 8 years lifetime? I notice they don't specify what temperature on
the box...

Tim
 
D

Don Klipstein

Jan 1, 1970
0
They are still expensive as heck, but you can get LED lamps. Perhaps
below US$50 each for 100W equivalent, but always over 30,000 power on
hours life and some (more expensive) are rated at over 100,000 hours
power on.

Buyer beware for life expectancy of LED "lightbulbs" and the like,
especially if they are white ones.

100,000 hours is a widely-repeated number, to the point of
"conventional wisdom".

White LEDs often fade significantly well before then - I dare to say
they mostly do. Colored LEDs, on the other hand, appear to me to have
most operated for 100,000 hours or more to be keeping on trucking
rather well after working for so long.

It appears to me that better heatsinkable white LEDs take 50,000 hours
to fade by 30% at "characterizing current" ("typical current") when
heatsunk to what I call a "moderately conservative extent". Much longer
life expectancy as in 100,00-plus hours appears to me reasonable if they
are both significantly underpowered and heatsunk to extent to keep the
junction temperature well below the "old traditional" maximum recommended
LED junction operating temperature of 85 C. In general, LEDs are more
efficient when cooler and most blue, white, and non-yellowish-green ones
are more efficient when moderately or moderately severely underpowered -
even regardless of temperature.

A main difference between white LEDs and most colored ones is that white
LEDs normally have a phosphor and over 99.9% of colored ones I have seen
don't.
The few colored LEDs that I have seen with phosphor are pastels, pink,
lavendar/"purple" (as opposed to "violet", which is nearly-UV or an
indigo-bluish-violet color with some "blacklight" effects), or a
non-amberish maybe-slightly-chartreusish yellow close to 255-255-0 on a
usual monitor.
Also beware - violet and UV LEDs with epoxy bodies tend to age fast due
to UV or nearly-UV being hard on the epoxy.

I have seen sone reasonably credible numbers for even better 5 mm /
T1-3/4 LEDs to fade significantly (don't know whether by 30% or 50%) in
as little as 6,000 to 10,000 hours. I don't know whether this is at
"characterizing current" of 20 mA or at maximum current of 30 mA. Some of
this is news years old and some I got more recently.

One model of a white LED nightlight that I tried had "half-life" close
to half a year. I would prefer green or blue LED nightlights over white
ones for better life expectancy as well as having a spectrum more
favorable for stimulating "scotopic vision" ("night vision").

- Don Klipstein ([email protected])
 
D

Don Klipstein

Jan 1, 1970
0
Wouldn't you know it, these are GE as well.

My general experience leaves me an impression that GE is 3rd-best,
behind Philips and Sylvania.

By-and-large, CFLs are "on average" better (in my experience) if they
are made by one of the "Big 3" (Philips, Osram/Sylvania, GE) or if they
have achieved the "Energy Star" rating.

Where I really have bad experience, as far as I remember now:

* Lights of America
(High rate of premature failures and failures to meet claims of light
output, though mostly before I largely stopped buying those in 2002)

* The dollar store stool specimens - I find them underperforming in so
many ways! I have yet to find one of the "dollar store brands" (or of
what I might even call lack thereof) make a claim of light output that
was met. My experience includes a few not even achieving 1/3 of
claimed light output. Most of these in my experience have an icy cold
bluish white color, including many that come in packages saying "soft
warm white light" - especially of the Telstar brand. My experience with
these "stool specimens" also includes above-average rate of outright
malfunctions, infant failures, and spectacular failures.

* Maxlite - my complaint there is being dimmer than most other CFLs
of same claimed light output and also in my experience (unlike most
Energy-Star-rated CFLs) being dimmer than incandescents of same claimed
lumen light output. Most of the time it was only a few percent but
sometimes it was much more, and never in my experience did I have one
of those fail to underperform at least a few percent where an overwhelming
majority of others, especially of of "Big 3" brands, mostly had lack of
underperformance in light output (at least until being "broken in").
Can they really sell a product that lasts maybe a year and claim it has,
idunno 8 years lifetime? I notice they don't specify what temperature on
the box...

My experience is that few do, and on the few where I saw a maximum
recommended ambient temperature on the package it was 60 C.

If you want a CFL that is better for "heat hellholes" (I suspect OK
above 60 C but not by a whole lot), then the answer is Philips
"Marathon"/SLS "triple arch" non-dimmable 15 watts.
That one, along with the 20 and 23 watt versions (but not dimmable nor
25 watt versions), are actually rated for recessed ceiling fixtures last
time I checked. However, I would not put one in an oven!

==============================================================

By "industry standard", life expectancy is with 3 hours per start and 25
degree C ambient.

I think more reasonable for screw-base CFL is 1 hour per start and 35
degree C ambient. Sometimes I want to say 40 degree C ambient. When I am
in a bad mood from Philadelphia-area summer heat I sometimes get a bit
into a mood to say 45 degree C ambient for life-testing of screw-base
"integral-ballast" CFLs.
But then again, if the manufacturers get these heat-tough enough to
rate their life expectancy for "any temperature 25 to 40 C", without
requirement of variation of temperature within this range, then I think
that most of the heat vulnerability problems (that have not yet been
solved in recent years) will be solved soon.

- Don Klipstein ([email protected])
 
J

JosephKK

Jan 1, 1970
0
Buyer beware for life expectancy of LED "lightbulbs" and the like,
especially if they are white ones.

100,000 hours is a widely-repeated number, to the point of
"conventional wisdom".

White LEDs often fade significantly well before then - I dare to say
they mostly do. Colored LEDs, on the other hand, appear to me to have
most operated for 100,000 hours or more to be keeping on trucking
rather well after working for so long.

Most of your sloppily called "colored" LEDs are standard monochromatic
LEDs. They are cheaper to manufacture that way.

White LEDs are for most purposes are a variation of fluorescent lamps.
(no Mercury content though)
It appears to me that better heatsinkable white LEDs take 50,000 hours
to fade by 30% at "characterizing current" ("typical current") when
heatsunk to what I call a "moderately conservative extent". Much longer
life expectancy as in 100,00-plus hours appears to me reasonable if they
are both significantly underpowered and heatsunk to extent to keep the
junction temperature well below the "old traditional" maximum recommended
LED junction operating temperature of 85 C. In general, LEDs are more
efficient when cooler and most blue, white, and non-yellowish-green ones
are more efficient when moderately or moderately severely underpowered -
even regardless of temperature.

One of the best reliability engineers i ever met liked things "nicely
derated". 3 W white LED, run it at 1W, you will like the life
improvement. Now, of course, time cost of money and time cost of
devices will interfere with this.
A main difference between white LEDs and most colored ones is that white
LEDs normally have a phosphor and over 99.9% of colored ones I have seen
don't.
The few colored LEDs that I have seen with phosphor are pastels, pink,
lavendar/"purple" (as opposed to "violet", which is nearly-UV or an
indigo-bluish-violet color with some "blacklight" effects), or a
non-amberish maybe-slightly-chartreusish yellow close to 255-255-0 on a
usual monitor.
Also beware - violet and UV LEDs with epoxy bodies tend to age fast due
to UV or nearly-UV being hard on the epoxy.

And it still surprises people.
I have seen sone reasonably credible numbers for even better 5 mm /
T1-3/4 LEDs to fade significantly (don't know whether by 30% or 50%) in
as little as 6,000 to 10,000 hours. I don't know whether this is at
"characterizing current" of 20 mA or at maximum current of 30 mA. Some of
this is news years old and some I got more recently.

One model of a white LED nightlight that I tried had "half-life" close
to half a year. I would prefer green or blue LED nightlights over white
ones for better life expectancy as well as having a spectrum more
favorable for stimulating "scotopic vision" ("night vision").

Good point, a lot of people still miss this one.
 
E

Eeyore

Jan 1, 1970
0
Eric said:
Instead of using white LEDs would it not be possible to use a number of
red, green, and blue LEDs create the effect of white light?

Been tried but looks pretty crappy AIUI. Wrong wavelengths vs the phosphors I
guess.

Graham
 
D

Don Klipstein

Jan 1, 1970
0
Instead of using white LEDs would it not be possible to use a number of
red, green, and blue LEDs create the effect of white light?

They actually do that. It gives a wierd color rendering effect - with
red objects coming out "day-glo" bright and wood tones coming up very
reddish/pinkish. Oak has a color like that of mahogany. Skin tones come
up reddish.

- Don Klipstein ([email protected])
 
J

JosephKK

Jan 1, 1970
0
They actually do that. It gives a wierd color rendering effect - with
red objects coming out "day-glo" bright and wood tones coming up very
reddish/pinkish. Oak has a color like that of mahogany. Skin tones come
up reddish.

- Don Klipstein ([email protected])

So how do they make the jumbotrons?
 
D

Don Klipstein

Jan 1, 1970
0
So how do they make the jumbotrons?

Since jumbotrons are not illuminating devices any more than TV sets and
computer monitors are, they are allowed to have a spectrum (when set
to "white") that gives such odd color rendering effects.

A display screen has R, G and B at any given point set to display a
desired color and brightness. Ability to do that well does not negate a
combo of all 3 having an overall color of white but a spectrum that causes
"distorted" color rendition of illuminated objects.

In my experience, most color rendition issues from "white" "artificial
light sources"
(excluding incandescent, uncored carbon arc and pure xenon
arc [which excludes automotive "xenon" HID headlights that are actually
metal halide once warmed up] and xenon strobes with sufficient combo of
capacitance and xenon pressure)
result from excess or deficiency of yellow/yellowish spectral content
compared to sum of red and green spectral content.

Mercury vapor, sodium vapor, metal halide in general (sometimes only
slightly), non-triphosphor fluorescent, and white LEDs have "excess
yellow" and "insufficient red-and-green". That results mainly in
red/reddish objects being "dulled" in color. Red objects also appear
darker than "proper". Skin tones, wood and brown paper bags and brown
corrugated cardboard appear less-red than "proper".
The same is true with xenon strobes with less capacitance of
energy-storage-capacitor and/or lower xenon pressure - especially lower
value for energy storage capacitor.

RGB light sources do the opposite - with above objects appearing
"more-red than proper" due to "insufficient" yellow/yellowish, and
"excessive" red and green spectral content.
That includes RGB LED light sources as well as (to a lesser extent) most
monitors being used as a white light source.

Triphosphor fluorescents do this just a little - but they "somewhat get
close to a middle ground" by having a "narrow main red band" that is a
very orangish shade of red (arguably a reddish shade of orange rather than
an orangish shade of red - 611 nm), and having the "green band" being a
cluster of yellowish green wavelengths centered around 542-544 nm. Along
with a little bit of yellow mercury wavelengths and minor yellow and
yellow-orange phosphor bands.

- Don Klipstein ([email protected])
 
D

Don Klipstein

Jan 1, 1970
0
[email protected] (Don Klipstein) wrote in
Don Klipstein wrote: [snip]
Instead of using white LEDs would it not be possible to use a number of
red, green, and blue LEDs create the effect of white light?

They actually do that. It gives a wierd color rendering effect - with
red objects coming out "day-glo" bright and wood tones coming up very
reddish/pinkish. Oak has a color like that of mahogany. Skin tones
come up reddish.

- Don Klipstein ([email protected])

Interesting. Would colors look more true if, in the lamp design, one
combined 2 green LEDs , 2 blue LEDs, and only one red LED...?

Colors would probably appear "better", but the overall color of the
light would be quite bluish.

Heck, equal numbers of R, G and B LEDs often results in bluish light.

http://members.misty.com/don/ledrgb2w.html

- Don Klipstein ([email protected])
 
J

JosephKK

Jan 1, 1970
0
So how do they make the jumbotrons?

Since jumbotrons are not illuminating devices any more than TV sets and
computer monitors are, they are allowed to have a spectrum (when set
to "white") that gives such odd color rendering effects.

A display screen has R, G and B at any given point set to display a
desired color and brightness. Ability to do that well does not negate a
combo of all 3 having an overall color of white but a spectrum that causes
"distorted" color rendition of illuminated objects.

In my experience, most color rendition issues from "white" "artificial
light sources"
(excluding incandescent, uncored carbon arc and pure xenon
arc [which excludes automotive "xenon" HID headlights that are actually
metal halide once warmed up] and xenon strobes with sufficient combo of
capacitance and xenon pressure)
result from excess or deficiency of yellow/yellowish spectral content
compared to sum of red and green spectral content.

Mercury vapor, sodium vapor, metal halide in general (sometimes only
slightly), non-triphosphor fluorescent, and white LEDs have "excess
yellow" and "insufficient red-and-green". That results mainly in
red/reddish objects being "dulled" in color. Red objects also appear
darker than "proper". Skin tones, wood and brown paper bags and brown
corrugated cardboard appear less-red than "proper".
The same is true with xenon strobes with less capacitance of
energy-storage-capacitor and/or lower xenon pressure - especially lower
value for energy storage capacitor.

RGB light sources do the opposite - with above objects appearing
"more-red than proper" due to "insufficient" yellow/yellowish, and
"excessive" red and green spectral content.
That includes RGB LED light sources as well as (to a lesser extent) most
monitors being used as a white light source.

Triphosphor fluorescents do this just a little - but they "somewhat get
close to a middle ground" by having a "narrow main red band" that is a
very orangish shade of red (arguably a reddish shade of orange rather than
an orangish shade of red - 611 nm), and having the "green band" being a
cluster of yellowish green wavelengths centered around 542-544 nm. Along
with a little bit of yellow mercury wavelengths and minor yellow and
yellow-orange phosphor bands.

- Don Klipstein ([email protected])

Sorry Don, i could not follow how what you posted relates to how
jumbotrons are built. Perhaps you could explain how it ties in.
 
D

Don Klipstein

Jan 1, 1970
0
Don Klipstein wrote:
On Sun, 24 Aug 2008 13:27:49 -0500, "Tim Williams"

I've got a problem. I happen to carry the distinction of being the one
responsible for changing lights. Much as that's a problem in itself, the
biggest problem is.....the front porch light (surprisingly, it's not a
stairway light, eh?), which happens to be a hanging, upside-down, enclosed
fixture. And they put two screws in the thing, so it's almost impossible
for a single person to replace the bulb thus inserted. Really quite
remarkable how no one thought of this.

Besides modifying it, which I may consider because it's just that bad, in
the mean time I need something that'll last. We've already tried the "ten
gajillion hour" CFLs, which died in all of, you know it, three months. I'm
guessing something high voltage (130V+?) and incandescent. Any
recommendations?
They are still expensive as heck, but you can get LED lamps. Perhaps
below US$50 each for 100W equivalent, but always over 30,000 power on
hours life and some (more expensive) are rated at over 100,000 hours
power on.

Buyer beware for life expectancy of LED "lightbulbs" and the like,
especially if they are white ones.

100,000 hours is a widely-repeated number, to the point of
"conventional wisdom".

White LEDs often fade significantly well before then - I dare to say
they mostly do. Colored LEDs, on the other hand, appear to me to have
most operated for 100,000 hours or more to be keeping on trucking
rather well after working for so long.

It appears to me that better heatsinkable white LEDs take 50,000 hours
to fade by 30% at "characterizing current" ("typical current") when
heatsunk to what I call a "moderately conservative extent". Much longer
life expectancy as in 100,00-plus hours appears to me reasonable if they
are both significantly underpowered and heatsunk to extent to keep the
junction temperature well below the "old traditional" maximum recommended
LED junction operating temperature of 85 C. In general, LEDs are more
efficient when cooler and most blue, white, and non-yellowish-green ones
are more efficient when moderately or moderately severely underpowered -
even regardless of temperature.

A main difference between white LEDs and most colored ones is that white
LEDs normally have a phosphor and over 99.9% of colored ones I have seen
don't.
The few colored LEDs that I have seen with phosphor are pastels, pink,
lavendar/"purple" (as opposed to "violet", which is nearly-UV or an
indigo-bluish-violet color with some "blacklight" effects), or a
non-amberish maybe-slightly-chartreusish yellow close to 255-255-0 on a
usual monitor.
Also beware - violet and UV LEDs with epoxy bodies tend to age fast due
to UV or nearly-UV being hard on the epoxy.

I have seen sone reasonably credible numbers for even better 5 mm /
T1-3/4 LEDs to fade significantly (don't know whether by 30% or 50%) in
as little as 6,000 to 10,000 hours. I don't know whether this is at
"characterizing current" of 20 mA or at maximum current of 30 mA. Some of
this is news years old and some I got more recently.

One model of a white LED nightlight that I tried had "half-life" close
to half a year. I would prefer green or blue LED nightlights over white
ones for better life expectancy as well as having a spectrum more
favorable for stimulating "scotopic vision" ("night vision").

- Don Klipstein ([email protected])
Instead of using white LEDs would it not be possible to use a number of
red, green, and blue LEDs create the effect of white light?

They actually do that. It gives a wierd color rendering effect - with
red objects coming out "day-glo" bright and wood tones coming up very
reddish/pinkish. Oak has a color like that of mahogany. Skin tones come
up reddish.

- Don Klipstein ([email protected])

So how do they make the jumbotrons?

Since jumbotrons are not illuminating devices any more than TV sets and
computer monitors are, they are allowed to have a spectrum (when set
to "white") that gives such odd color rendering effects.

A display screen has R, G and B at any given point set to display a
desired color and brightness. Ability to do that well does not negate a
combo of all 3 having an overall color of white but a spectrum that causes
"distorted" color rendition of illuminated objects.

In my experience, most color rendition issues from "white" "artificial
light sources"
(excluding incandescent, uncored carbon arc and pure xenon
arc [which excludes automotive "xenon" HID headlights that are actually
metal halide once warmed up] and xenon strobes with sufficient combo of
capacitance and xenon pressure)
result from excess or deficiency of yellow/yellowish spectral content
compared to sum of red and green spectral content.

Mercury vapor, sodium vapor, metal halide in general (sometimes only
slightly), non-triphosphor fluorescent, and white LEDs have "excess
yellow" and "insufficient red-and-green". That results mainly in
red/reddish objects being "dulled" in color. Red objects also appear
darker than "proper". Skin tones, wood and brown paper bags and brown
corrugated cardboard appear less-red than "proper".
The same is true with xenon strobes with less capacitance of
energy-storage-capacitor and/or lower xenon pressure - especially lower
value for energy storage capacitor.

RGB light sources do the opposite - with above objects appearing
"more-red than proper" due to "insufficient" yellow/yellowish, and
"excessive" red and green spectral content.
That includes RGB LED light sources as well as (to a lesser extent) most
monitors being used as a white light source.

Triphosphor fluorescents do this just a little - but they "somewhat get
close to a middle ground" by having a "narrow main red band" that is a
very orangish shade of red (arguably a reddish shade of orange rather than
an orangish shade of red - 611 nm), and having the "green band" being a
cluster of yellowish green wavelengths centered around 542-544 nm. Along
with a little bit of yellow mercury wavelengths and minor yellow and
yellow-orange phosphor bands.

- Don Klipstein ([email protected])

Sorry Don, i could not follow how what you posted relates to how
jumbotrons are built. Perhaps you could explain how it ties in.

A "jumbotron" is a jumbo large monitor using R, G, and B LEDs. As in
each pixel has at least one LED of R, G and B.

The tie-in is from a "Jumbotron" having ability to be (though having low
usage as) a "white light source".

- Don Klipstein ([email protected])
 
D

Don Klipstein

Jan 1, 1970
0
[email protected] (Don Klipstein) wrote in
[email protected] (Don Klipstein) wrote in

Don Klipstein wrote:
[snip]
Instead of using white LEDs would it not be possible to use a number of
red, green, and blue LEDs create the effect of white light?

They actually do that. It gives a wierd color rendering effect - with
red objects coming out "day-glo" bright and wood tones coming up very
reddish/pinkish. Oak has a color like that of mahogany. Skin tones
come up reddish.

- Don Klipstein ([email protected])

Interesting. Would colors look more true if, in the lamp design, one
combined 2 green LEDs , 2 blue LEDs, and only one red LED...?

Colors would probably appear "better", but the overall color of the
light would be quite bluish.

Heck, equal numbers of R, G and B LEDs often results in bluish light.

http://members.misty.com/don/ledrgb2w.html

- Don Klipstein ([email protected])

Oh, so then, it wouldn't offset the "day-glo red" effect :(

Although you've gotten me thinking about a possible variation on the
"flickering candle" LED lights- since a candle flame actually consist ofa
progression of colors (basically, very small blue core, large white band,
moderate yellow band, and small red band), I'm wondering wbout setting up a
series of flickering LEDs in that sort of pattern. That's just off the very
top of my head, but I'm trying to picture whether it'd look interesting-
enough to put more thought into it.

I have looked at candle flames enough, and it appears to me that over
99% of the light is from the whitish/yellow-yellow region, in the form of
close enough to blackbody radiation at color temperatures in a range
mostly within a couple hundred degrees of 1900 K.

If you put random noise through a narrowband filter centered around 6 Hz
or so and have that modulate the brightness of a 1900 Kelvin source,
that's already most of the way there. The next refinement would be to
modulate the color slightly (maybe 50 Kelvin) - with color temperature
varying inversely with brightness, maybe not exactly 180 degrees out
of phase from brightness.

- Don Klipstein ([email protected])
 
J

JosephKK

Jan 1, 1970
0
[email protected] (Don Klipstein) wrote in
Kris Krieger said:
[email protected] (Don Klipstein) wrote in

[email protected] (Don Klipstein) wrote in

Don Klipstein wrote:
[snip]
Instead of using white LEDs would it not be possible to use a number
of red, green, and blue LEDs create the effect of white light?

They actually do that. It gives a wierd color rendering effect -
with
red objects coming out "day-glo" bright and wood tones coming up
very reddish/pinkish. Oak has a color like that of mahogany. Skin
tones come up reddish.

- Don Klipstein ([email protected])

Interesting. Would colors look more true if, in the lamp design, one
combined 2 green LEDs , 2 blue LEDs, and only one red LED...?

Colors would probably appear "better", but the overall color of the
light would be quite bluish.

Heck, equal numbers of R, G and B LEDs often results in bluish
light.

http://members.misty.com/don/ledrgb2w.html

- Don Klipstein ([email protected])

Oh, so then, it wouldn't offset the "day-glo red" effect :(

Although you've gotten me thinking about a possible variation on the
"flickering candle" LED lights- since a candle flame actually consist
ofa progression of colors (basically, very small blue core, large white
band, moderate yellow band, and small red band), I'm wondering wbout
setting up a series of flickering LEDs in that sort of pattern. That's
just off the very top of my head, but I'm trying to picture whether it'd
look interesting- enough to put more thought into it.

I have looked at candle flames enough, and it appears to me that over
99% of the light is from the whitish/yellow-yellow region, in the form
of close enough to blackbody radiation at color temperatures in a range
mostly within a couple hundred degrees of 1900 K.

If you put random noise through a narrowband filter centered around 6
Hz
or so and have that modulate the brightness of a 1900 Kelvin source,
that's already most of the way there.
The next refinement would be to
modulate the color slightly (maybe 50 Kelvin) - with color temperature
varying inversely with brightness, maybe not exactly 180 degrees out
of phase from brightness.

- Don Klipstein ([email protected])

Er, that's a bit advanced for me...I'm just starting to teach myself a little
bit about "555 timer" =:-o

But could you do all that modulating with an LED as the light source...? I
thought they had fixed colors and could only get brighter or dimmer with
changes in voltage. It'd be cool if you could actually modulate and LED like
that.

I think that the flickering effect would be especially attractive inside of a
clear-textured glass enclosure/construct.
Actually for this case merely output modulating the longer wave
(redder) length LEDs more deeply should do the trick.
 
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