How many lumens in latest T1-3/4?

[Oznog]

The old tried-and-true T1-3/4 5mm LED package- how many lumens can they make now?

I remember the estimate of 1 lumen from awhile back. I actually saw a spec here:
http://www.besthongkong.com/files/spec/LDHL/BUWDC333W20BA14.pdf

for a T1-3/4 claiming 4.5 lumens at 20mA. Now a few yrs back, 4.5 lumens would be impossible since the package won't handle the heat. But efficiencies have increased so I don't see why that'd be impossible now.

Do they go even higher than 4.5 lumens too, in actual production parts? Not just some claim by a mfg that they achieved something in the lab?

 

[paulr]

Yes the Nichia 500GS found in the Fenix E01 runs at spec power (20 ma) and gets around 10 lm from the led, maybe around 6 out the front of the light. The Arc AAA overdrives it and gets around 15 from the led or 10 out the front.

 

[2xTrinity]

Yes the Nichia 500GS found in the Fenix E01 runs at spec power (20 ma) and gets around 10 lm from the led, maybe around 6 out the front of the light. The Arc AAA overdrives it and gets around 15 from the led or 10 out the front.

There shouldn't be any lumen output decrease from the 5mm LED "bulb lumens" to out the front. The 5mm LED itself IS the reflector/optic, and tere's not additonal windows/reflectors added. The only losses there sohuld be are the light that leaks out the sides and back due to unwanted reflections from the exit interface, which should be less than 10%, I would argue that that light is already "lost" anyway.

From the 5mm white LED testing thread. The Nichia LED itself gets about 7 lumens @ 20 mA, or 10lm @ 30mA (overdrive).

 

[jtr1962]

The old tried-and-true T1-3/4 5mm LED package- how many lumens can they make now?

I remember the estimate of 1 lumen from awhile back. I actually saw a spec here:
http://www.besthongkong.com/files/spec/LDHL/BUWDC333W20BA14.pdf

for a T1-3/4 claiming 4.5 lumens at 20mA. Now a few yrs back, 4.5 lumens would be impossible since the package won't handle the heat. But efficiencies have increased so I don't see why that'd be impossible now.

Do they go even higher than 4.5 lumens too, in actual production parts? Not just some claim by a mfg that they achieved something in the lab?

Here's a chart of every small LED I've tested:

As you can see, quite a few of them are over 4.5 lumens at 20 mA. Actually, as you get more lumens out that means less heat for the package to deal with, not more. A hypothetically 100% efficient LED would make all light and no heat. The Nichia GS is the best I've tested so far, and it only converts about 30% into light.

 

[Oznog]

Hey, check out this one, it's a modified lead design but still a 5mm T1-3/4:

http://www.besthongkong.com/product_info.php?cPath=75_1_14&products_id=526

Rated for 100mA (though heatsinking the leads is necessary). 20 lumens. 57lumens/watt isn't impressive these days though, and obviously a 5-chip design is WAY too big for a 5mm package to focus (50 deg throw).

 

[jtr1962]

Hey, check out this one, it's a modified lead design but still a 5mm T1-3/4:

http://www.besthongkong.com/product_info.php?cPath=75_1_14&products_id=526

Rated for 100mA (though heatsinking the leads is necessary). 20 lumens. 57lumens/watt isn't impressive these days though, and obviously a 5-chip design is WAY too big for a 5mm package to focus (50 deg throw).

I actually tested that one. It performed fairly close to spec:

BestHongKong 25000 mcd 5mm 5-die white (acquired March 2008)

CPF member TMorita sent me 3 samples of this LED for testing. These are BestHongKong's 5-die whites which have 5 dies and a larger lead frame to allow operation at 100 mA. The results were 6.0, 6.5, and 6.9 cd at 20 mA. I assume the 25,000 mcd rating is at 100 mA, so the corresponding results at 100 mA are 24.3, 25.8, and 28.1. The average is 26.1 cd, slightly above spec. Average beam angle was 34.7°, less than the specified 50°. Color temperature was around 7000K, and the beam was very smooth. Average efficiency of the three samples was a decent 72.8 lm/W at 20 mA and 52.9 lm/W at 100 mA. I was expecting somewhat better than that due to the 5-die construction. Apparently they're not using the most efficient dies for these. Average output was 4.07 lumens at 20 mA, and average Vf was a low 2.87V (expected due to the 5-die construction). Corresponding figures at 100 mA were 16.41 lumens and 3.10V. The 16.41 lumens comes reasonably close to the specified 20 lumens at 100 mA. Consistency between samples was excellent-outputs were 3.91, 4.14, and 4.16 lumens at 20 mA. Output scales very well with current as expected (output at 100 mA is 4.03 times the output at 20 mA). Overall these appear to be a decent, well-constructed LED capable of sustained operation at higher currents.