What's a nice LED to run at 60 - 120mA?

Bimmerboy

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Dec 30, 2004
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Long Island, NY
I'll soon be making a couple low power lights using vampire circuits that will deliver 50 - 60mA on a fresh 1.5V cell, and roughly 120mA on 2 of 'em. Of course, current will go down as the batteries drain.

The main thing I'm wondering about is tint at low current. Back in the day, some LED's went really green when running low, for example the MC-E, which should tell ya'll the last time I bought a power LED... lol. What's good to run at this level and not look weird? Hoping for something relatively white looking.

Open to all suggestions, as long as I can get it already mounted on a star.
 

LEDphile

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Mar 8, 2021
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At those drive levels, you should be looking at mid-power LEDs. They are designed to be run at ~100mA, and typically have better efficiency than high-power LEDs. Only downsides are that they aren't as readily available on star boards and there are fewer optic choices for them (if that matters for your application). As far as specific choices, you could do far worse than the Nichia 757 series.
 

Dave_H

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Nov 3, 2009
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Ottawa Ont. Canada
I know what you mean about weird tints at low current. Early (5mm white) LEDs showed a greenish or purplish tint at very low currents. I have not seen this recently, have some cases of ordinary 5mm white running at very low currents (microamps!) maintaining a good tint.

Does it matter if they are SMT or leaded?

I can't suggest specific LEDs. "Superflux" are typically good up to 60mA, often in 4-pin DIP package. If you don't mind salvage, some ac LED bulb SMT LEDs are good in this range although many recently appear to be duals or triples (maybe even quad die) in series, which probably would not work well for your case.

Dave
 

HarryN

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Jan 22, 2004
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Pleasanton (Bay Area), CA, USA
If your goal is to use it for a flashlight with some throw, then it needs to be run closer to it's upper limits to get the high surface brightness.

If the goal is a light for looking at things around the house or finding stuff in dark corners, then in general you will want to under power the LED and get a softer output.

I continue to be a lumileds fan. Both they and nichia make some interesting leds with wide spectral ranges that are good for "finding things" if you are not too picky about the "look".

Similar to you, I try to avoid soldering leds onto stars. Luxeonstar and ledsupply have a lot of options.
 
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