We've come a long way indeed! And to think that blue LEDs have only been on the market since the mid '90s. They spread fast!
The cheapest colour because so many are used in LCD panels and lighting.
The downside is the forward voltage and lifetime
25 years is a quarter of a century, I'd not call that fast exactly, the patents will have all expired!
It pleases me to see I am not the only one experiencing this. I bought purple and pink LEDs and both were glowing blue after a few weeks. At a low current, I did not run them hot or something like that.
Anyhow, my latest device uses a black LED which is very refreshing.
Somewhere I have some black ones, but allegedly they are just IR LEDs dyed black in the optical... I can see why they do that for IR photodiodes to reduce effects of stray light, but why for an IR emitting LED??
I know, I know. Still seems fresh to me.
The first blue LED I ever saw was in a Volkswagen. Don't remember the model. Sporty one, I think. Wow! A blue LED! Good memories.
I'm surprised at the anti-white-LED sentiments. You'd think this crowd, above others, would appreciate that we now CAN have white LEDs.
I think they are quite stylish. I suppose in 10 years we'll be as sick of them as the blue LEDs. But for the moment white is a good choice.
I think a lot of people have bad experiences with white LEDs because they tend to be blinding. I have no issue with the white LEDs on my Apple products. They're small and relatively dim.
Blue is OK as well ... as long as it's not blinding. Mouser has exactly one (1) blue LED in stock that I like.
HiFi shows in the mid/late 1990s were bathed in blue LED light. I remember a Krell amp that had three blue LEDs on the front panel casting a cone of light on the floor similar to a flashlight beam. Too much, too much...
Tom
Blue is OK as well ... as long as it's not blinding. Mouser has exactly one (1) blue LED in stock that I like.
HiFi shows in the mid/late 1990s were bathed in blue LED light. I remember a Krell amp that had three blue LEDs on the front panel casting a cone of light on the floor similar to a flashlight beam. Too much, too much...
Tom
Some IR diodes are 900nm and quite invisible to the eye.
IR diodes for fibre optics used to be 850nm and the tail of their emission curve was just visible.
Transmitters might also use an optical filter to make them less visible to ccd cameras
Purple or pink are my choices. A cheap source of pink LEDs is a Christmas light string, 20 or 40 for next to nothing, all with longish wiring tails. I just snip another one off every now and then. Pink up-lighting on my amps is my latest lockdown time waster. 😀 A 100k 21 turn trimmer as a voltage divider lets me set them all at a similar level.
If you think about it a light source only has hue and saturation as the brightness depends on distance and lenses etc, whereas a pigment has hue, saturation and lightness, so the colours we use to describe objects are a superset of those that describe light sources.
For instance lights are never brown, as that's just dark orange, and I've never been convinced that indigo is a colour of the rainbow, its not a synonym for blue/violet its simply dark blue. Thus the rarest LEDs are brown, beige and indigo. And kharki also 🙂
For instance lights are never brown, as that's just dark orange, and I've never been convinced that indigo is a colour of the rainbow, its not a synonym for blue/violet its simply dark blue. Thus the rarest LEDs are brown, beige and indigo. And kharki also 🙂
The fading purple LEDs must have a fluorescent coating (as do white LEDs).
An LED produces a specific wavelength of light.
Some difficult to produce LED colours use a UV LED and a fluorescent coating.
An LED produces a specific wavelength of light.
Some difficult to produce LED colours use a UV LED and a fluorescent coating.
Yes, fading phosphor is likely the cause. I haven't bought any purple or pink in years, do they still fade? I was about to buy some C7 size LED pink Christmas lights for another project. Don't know if they'll last.
The pink Christmas lights I use haven't noticeably faded in the last couple of years. Nor the purple push-button LEDs.
I prefer to have only one LED color visible at any one time on a component; more than that seems too carnival-like for my taste. My Pass-related projects all have blue LEDs, in deference to NP. They may also have a single red LED to indicate when the unit is in stand-by mode.
I'm at the beginning stages of a Salas UFSP build and that will have orange LEDs, which will match the LEDs on my other turntable-related devices (an SG-4 speed controller and a wired remote control to power my turntable's air pumps).
Invariably, I run LEDs at low levels -- 4 to 6 mA is my norm.
Oddly, I have LEDs in about 8 different colors in my collection. Whether I'll ever get around to using some of those colors is a mystery to me.
Regards,
Scott
I'm at the beginning stages of a Salas UFSP build and that will have orange LEDs, which will match the LEDs on my other turntable-related devices (an SG-4 speed controller and a wired remote control to power my turntable's air pumps).
Invariably, I run LEDs at low levels -- 4 to 6 mA is my norm.
Oddly, I have LEDs in about 8 different colors in my collection. Whether I'll ever get around to using some of those colors is a mystery to me.
Regards,
Scott
Hi Scott, I experience recently produced 3 mm LEDs in red/green to glow at low levels only below 2.5 mA otherwise they are just too bright. I guess you mean blue LEDs to glow at low levels @ 4-6 mA?
Last edited:
Jean-Paul:
Yes, you're right -- I typically run blue LEDs at 4 to 6 mA. Warmer colors are often run at about half that level. Thanks for catching my blunder!
Regards,
Scott
Yes, you're right -- I typically run blue LEDs at 4 to 6 mA. Warmer colors are often run at about half that level. Thanks for catching my blunder!
Regards,
Scott
For power indicators I like a mixture of blue and green. Now I don't like green by itself and I don't like blue by itself unless it's almost purple. But this turqouise or mint-green looks really nice with a black enclosure.
But if you want to be on the cutting edge there is no way around RGB for sure.
But if you want to be on the cutting edge there is no way around RGB for sure.