LG 365nm UV led tested (LEUVA33W70RL00, from Simon)

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djozz
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LG 365nm UV led tested (LEUVA33W70RL00, from Simon)

This is the newest 365nm led that the Convoy aliexpress store has for sale, although it has been on the market for at least 2 years, just not affordable for private buyers until now. Simon only sells it already reflowed on a 16mm copper DTP board and that is how I tested it. Unfortunately they (I ordered 2) were extremely dirty, so I had to do extensive cleaning of the die (tissue and isopropanol) before I could start the test. Here’s the two boards that I bought, the left led I already cleaned for the test. (It is not competely clean, I wished Convoy sold the bare led in original packaging)

Compared to the previous LG 365nm led that was for sale on the Convoy store, which was already among the top performers of the 365nm leds that I measured sofar, this has a bigger die and promises more output. Let’s see. Here’s the new LG led compared to the previous one, for the picture they were wired in series so they receive the same
( <50mA) current:

I used my 2017 method for measuring output, deriving the output indirect by measuring UV-light induced fluorescence in uranium glass. I defined a unit called djozz-mW that allows me to compare different leds and has hopefully some relation to the actual radiant power. This being a rougher and more indirect method, do not expect the accuracy of my white led tests. For details, see link.

The output is a bit better than the former LG led but seeing how much larger the die is I expected a larger difference. But what is more relevant is that this led has almost 0.3V lower voltage at the interesting currents. That makes this led clearly more efficient than the previous generation, and easier to use in current-regulated flashlights.

The surface brightness of the die in his new led is actually a bit less than the previous generation: the limited higher output does not make up for the much larger die.

Edited by: djozz on 01/05/2019 - 20:06
CRX
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moderator007
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Thanks for the testing djozz. The lower vf should help alot with single cell builds. Beer

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Hey Djozz Nice work.

Today I just finished 3 Sofirn C8f triples with these new LG led’s based on your previous testing and posts. I already had a c8f with triple Seoul Viosys Z5 to compare it with. Anecdotally both lights put out similar quantity of light but the hotspot on the LG light is about twice the size. (the Z5 seems to throw twice as far). Also I had the same problem as you with dirt and wish they just sold emitters. Thanks again for putting in all the work to do this testing.

In another post you mentioned a relatively high power 75mw UVC emitter. Do you know where I can purchase on one of these ?

djozz
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You have been busy! Smile

Yes, in my test above, at 1.6 A, the new LG puts out just 6% more light than the old LG that performed the same as the Seoul Viosys led, assuming all currents are the same. A 6% output increase will hardly be noticed especially when the hotspot has a different size.

A 75mW UVC emitter costs hundreds of dollars, as far as I know (example). Coincidently Scientist may be sending me a high power UVC led for testing but I would not spend that money on one myself.

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305nm 100mW is a bit more affordable but as UVB less efficient to kill bacteria
https://shop.irtronix.com/products/lg-305nm-100mw-leuva66h00ku00

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Yeah Djozz I may have a problem shipping those out of the country. I will PM you if I can get approval.

djozz
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Scientist wrote:
Yeah Djozz I may have a problem shipping those out of the country. I will PM you if I can get approval.

Sure, no hurry, I see it as a lucky opportunity if you succeed Smile
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djozz wrote:
You have been busy! Smile

Yes, in my test above, at 1.6 A, the new LG puts out just 6% more light than the old LG that performed the same as the Seoul Viosys led, assuming all currents are the same. A 6% output increase will hardly be noticed especially when the hotspot has a different size.

A 75mW UVC emitter costs hundreds of dollars, as far as I know (example). Coincidently Scientist may be sending me a high power UVC led for testing but I would not spend that money on one myself.

If you do no torture test on this LED I may buy it after you are finished

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LOL, such an expensive led is not going to be torture-tested for sure Shocked , but I will not sell what I have not payed for, sounds not very fair to Scientist.

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Thanks for the testing djozz.

Is the new led on the left hand side still dirty in the last picture?

 

djozz quotes, "it came with chinese lettering that is chinese to me".

                      "My man mousehole needs one too"

old4570 said "I'm not an expert , so don't suffer from any such technical restrictions".

Old-Lumens. Highly admired and cherished member of Budget Light Forum. 11.5.2011 - 20.12.16. RIP.

 

djozz
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MRsDNF wrote:
Thanks for the testing djozz.

Is the new led on the left hand side still dirty in the last picture?


No, it is the cleaned one Sad , probably it will not influence performance but the silicon has some pits here and there.
d_t_a
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Probably not the correct place to ask this question, but was wondering…

Convoy sells the Convoy S2 with LG UV LED. I wonder if that Convoy S2 uses the older LG or the newer LG UV365 LED?

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Thanks again Djozz for the testing!! Djozz-mW...that's funny Big Smile 

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djozz wrote:
LOL, such an expensive led is not going to be torture-tested for sure Shocked , but I will not sell what I have not payed for, sounds not very fair to Scientist.

I can Pay Scientist

TBone
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Thanks for the test, djozz.

djozz wrote:
But what is more relevant is that this led has almost 0.3V lower voltage at the interesting currents. That makes this led clearly more efficient than the previous generation, and easier to use in current-regulated flashlights.
Looking at if from the other direction it means the radiant output at 3.7 V is not 1070 djozz-mW (at 0.8 A) but 2100 djozz-mW (at 2 A).
That is a huge difference.