Tested some white 20ma flux LEDs

[JohnR66]

I bought some 20ma white "flux" LEDs from ebay seller "LVEHK" aka "Light of Victory" and tested them out. Here are my results to share.


THE GOOD: No lumen depreciation in my 192 hour 30 ma fade test.:thumbsup: Brighter than 5mm wide angle LEDs. Large rectangular cathode for good thermal management (better than other flux style LEDs). Very good price.


THE BAD: These are not binned. They came very cool white to yellow white. In the 50 pack I bought, 10 were yellow white, 4 were neutral white and the rest were very cool white (purplish white). It is a shame they don't bin them. I like the yellow white and neutral white the best. Naturally, I got the least of these.


NOTES:
These seem to have rectangular die.
Upper right LED in the control group is bluer than tested one (hard to match visually).
Visual half brightness point is around 90 Deg.
Yellow white color I mentioned is not the more orangish shade of warm white LEDs. The top pic shows the colors.


I recommend them for low current, multi LED lighting projects. The far better thermal management, estimated longer lifetime and higher brightness make them ideal where a few of these are still cheaper than a power LED (like a Cree XR-E).


After trying these, my love of 5mm LEDs is diminished. Flux LEDs are much better for lighting projects that need a flood beam.:thumbsup:

 

[Holepuncher]

I have used some of these flux led's for lighting a couple of dark hallways and stairways. I think mine were made by Optek and they are all consistent color. I mounted them about 1 inch above the baseboards by drilling 4 tiny holes that match the footprint of the flux package and then pressing the leads into the wall. They are lit 24/7 and run off the alarm system battery. The hallway ones (2) are running at only 2mA and at night they light the hallway quite nicely. The stairway ones (3 of them) I'm running at 30ma because the stairway is dark even during the day but at night the stairway is quite bright. Day or night they look sharp and do a nice job.

 

[jason 77]

I have used some of these flux led's for lighting a couple of dark hallways and stairways. I think mine were made by Optek and they are all consistent color. I mounted them about 1 inch above the baseboards by drilling 4 tiny holes that match the footprint of the flux package and then pressing the leads into the wall. They are lit 24/7 and run off the alarm system battery. The hallway ones (2) are running at only 2mA and at night they light the hallway quite nicely. The stairway ones (3 of them) I'm running at 30ma because the stairway is dark even during the day but at night the stairway is quite bright. Day or night they look sharp and do a nice job.

got any pictures of you hallway lit up by the leds?

 

[Fallingwater]

I've been toying with the idea of trying out some of those flux LEDs, but the problem is that while good for fixed lighting, their package makes them unwieldy for use in most existing portable systems. You'd have to design a flashlight around them, or somehow adapt a larger body meant for more/different emitters.
In contrast, "multichip" LEDs such as these can be adapted to existing lights with little more than a driver/resistor replacement and perhaps some boring and a reflector.

 

[JohnR66]

I've been toying with the idea of trying out some of those flux LEDs, but the problem is that while good for fixed lighting, their package makes them unwieldy for use in most existing portable systems. You'd have to design a flashlight around them, or somehow adapt a larger body meant for more/different emitters.
In contrast, "multichip" LEDs such as these can be adapted to existing lights with little more than a driver/resistor replacement and perhaps some boring and a reflector.

I agree. The flux chip is better suited for fixed lighting.

I tried some of these 1/2 watt multi chipers from this seller (the 10mm narrow beam version) These are 4 chip LEDs. If truly 1/2 watt, they would need around 140 ma. At this current they faded a lot after a couple weeks. Probably okay for intermittant flashlight use though.

I tried some 3 chip 8mm straw hats from another seller. They too were rated 1/2 watt, but nearly failed. The epoxy over the LED actually burned a bit. better not go over 60ma with them.

Look for my tests of these in this forum from last Fall.

For now, I'm roasting the little 20ma flux LED at 50ma. After 48 hours it has not faded. After 192h I'll post a report.

 

[Holepuncher]

got any pictures of you hallway lit up by the leds?

OK. Best I can do on the pics.

Here is the hallway. This is definetely a little overexposed. Its not that bright at 2mA. I kept the current low because I did not want the light spilling into the bedroom at night. It is more than enough light to navigate the hallway at night.

And here is the stairway. This came out awful. The colors are all wrong. The led's are not bluish and the tile at the stairway landing is actually slate colored. The carpet runners are gray though. Got me:thinking:

JohnR66: These are Optek #OVFSW6C8. The ones in the stairway have been running at 30 or so ma for about a year and I have not noticed any degradation. Edit. Oops. I just looked up the specs on these. They are rated at 30mA so I'm not overdriving them by much. Other specs are 1200mcd, 60 deg and 6500K

 

[Fallingwater]

I tried some of these 1/2 watt multi chipers from this seller (the 10mm narrow beam version) These are 4 chip LEDs. If truly 1/2 watt, they would need around 140 ma. At this current they faded a lot after a couple weeks. Probably okay for intermittant flashlight use though.

If you have any spare LEDs/time/workbench space, you could test one at a 100mA current. I have a few similar ones myself (a limited-number batch on DX), and I've read that you shouldn't drive them at much more than that.

 

[JohnR66]

If you have any spare LEDs/time/workbench space, you could test one at a 100mA current. I have a few similar ones myself (a limited-number batch on DX), and I've read that you shouldn't drive them at much more than that.

Indeed I did test them at 100ma for 192 hours. Please see the test here:
http://www.candlepowerforums.com/vb/showthread.php?t=214330

 

[Fallingwater]

Oh well, so much for that.
Looks like I'll have to think of some way of hacking up a flux LED flashlight... :thinking:

 

[JohnR66]

"Roasting" is over!

The roasting is over. I fed the 20ma flux LED 50ma for 192 hours. The LED certainly got warm (which means nothing good is going to happen).

The result is some lumen depreciation or to put it simply, fading. To the eye, the LED didn't seem to change much, but the camera's sensor is more sensitive to light levels and it shows clearer. To view the results, I drive both LED in series so the current is the exact same. I photograph them through white plexi touching the top of the LEDs for consistancy.

Consider the original test as the performance test. I did this "roast" test just to see what would happen. I would not recommend cooking a 20ma LED for so many hours at such high current.

What's cooking now? I am testing some warm white LEDs and have some WW 20ma fluxes on the way. I was put off by the severe fading of a 5mm WW I tested before. I'm hoping these perform better in my 192 hour 30ma overdrive test. The test will wrap on Saturday. I should get something posted soon after. I'll start testing the WW fluxes as soon as they get here from Hong Kong.

I did a swap of some of my "Light of Victory" LEDs with "JELED"s with another CPF member. I will compare them as soon as I get them in.