Blue LEDs at Mouser (non retina burning)

I got some blue LEDs on my last Mouser order that work well in a Shruthi with the standard 220R current-limiting resistors. The part number is 78-TLHB4400

They’re bright, but not obnoxious- equivalent to the blue LEDs on a Doepfer Dark Time or a Future Retro Orb. I suspect that they’re actually the same LEDs used in the Orb because they have the same funny greenish tint when mounted in a panel but not illuminated.

Thanks for sharing.

Im pretty sure they are the same as i’ve used in the past… And yes, they do look oddly green when off.

The actual blue (and the red for that matter) doesn’t come out so well on cam. But you get the idea :slight_smile:

Some background on the dark side of blue LED phenomenon. Seems there’s been an arms race to produce the most eye catching LEDs.


Part of the problem is blue LEDs from many sources use a different technology which makes them brighter. Some have managed to get blue LEDs working with the old LED tech, which makes them less bright.

But apparently our eyes can’t focus on the bright blue light very well. I’d rather not take the risk :slight_smile:

^ Because blue LED’s for a long time only seemed to be available in “AArrgghh Too Bright!” versions. If you can track down some tamer ones, like we’re using here, then they are no worse than any other colour.
These are about the lowest mcd value as is possible to get in blue.
I think even since that article was written in 2007, more sensible blue LED’s have become rather easier to come by.

Fashionable/trendy or not. I like them :stuck_out_tongue:

Well it seems blue light messes with your body clock. It must be like seeing daylight :slight_smile:

The background is that our eyes are less sensitive to the blue end of the spectrum (presumably because the sky is blue, so there’s a lot of blue light around), so to make blue LEDs as perceptually bright as other colours, you have to make them more powerful. That’s my understanding of the situation, anyway.


Skin is blue? maybe if you live with the Na’vi :slight_smile:

I tend to trust Apple when it comes to HCI and design principles and they’ve never bothered with loads of bright annoying lights. They tend to use white lights and not very bright.

Oops… that was supposed to be ‘sky’, not ‘skn’…


Just for clarification, can we substitute these blue LEDs for the LEDs on the regular control board? Are there any voltage issues to worry about?

I, for one, would love blue LEDs. In fact I think I would be willing to tear some others out just to put them in if I can. I’ve got moderate red/green color blindness. It means that certain shades of green look brown to me etc. I can’t tell the difference between the “orange” LEDs and yellow ones. When manufacturers put in one LED that lights up 3-4 different colors to indicate different things, I usually can’t tell the difference between two of them.

But I can always see BLUE!

No real voltage issues, just as long as you make sure to get low mcd rated ones. You really want 40mcd or less. It’s always a good idea to do a little brightness check before finally soldering everything into place though. So be prepared to use more resistance. Anything up to maybe 10k, depending on the brightness of the LED.
But the ones we’re talking about here are fine with 220ohms, in my experience.

The red ones on my MB6582 are 10mcd, I wouldn’t want anything brighter than that.

My understanding is that the perceived brightness varies with colour, so the same mcd value may not result in the same apparent brightness.


^ Right :slight_smile:
Plus I don’t think you’ll find any blues at 10mcd anyway. But there is a reasonable choice under 50mcd now. And compared to the usual hyper bright blue retina burners, <50mcd isn’t a lot at all.
Plus different manufacturers spec these things in different ways. I’ve got some 35mcd blue LED’s that are brighter than some 50mcd blue LED’s.
The ones in the pict I posted above are 40mcd, if I remember rightly. The 2 red ones however are a mere 2.1mcd. All are fed via 220 ohm resistors. And as you can see, the difference in perceived brightness isn’t significant.

These are definitely on my next Mouser order then.

The LED linked to in the OP is 15 mcd.

Thread necro alert!

Evol, retina-burning or not - Blue (and hence white) LEDs got awarded the Nobel prize today. What’s up with that? A Nobel physics prize even people outside of science and research can readily grasp. Must be a sign of some mistake…

Like the 2009 prize to the CCD…? :slight_smile:

Yeah, there’s been a few of those lately. I was kind of expecting something involving elementary particles, quantum theory and formulas that even Stephen Hawking would have trouble understanding :slight_smile: