360nm leds from GB seem not so uv

These are the leds I purchased from the group buy from Chimo about 3 weeks ago. I purchased 20 of these uv leds at 360 nm.

I know this may seem strange, but my photon freedom @370nm seems to flouresce better than these @360nm. Also my $50's lite up orange with the photon, as where the GB 360nm dont even light up the $50. Even stains in the bathroom light up better using the photon freedom, as where the 360nm barely light up. Of course neither 370nm or 360nm lights up the 100 dollar bill.

Am I missing something?

I was going to put these in a cluster of 3 or 5, but now am having second thoughts.

Jim

Hmmmm. Where have I seen this post before?

WOW... your a detective. I posted it under the group buy that was originated by chimo.

Since this is not a group buy, I posted it here as there is probably more exposure here under leds, than there> group buys.

Mine are working fine, haven't tried them on stains....
but cards, IDs and money light up just great.

What about the others?
How are the rest of you finding the leds?

attowatt said:

WOW... your a detective. I posted it under the group buy that was originated by chimo. . . .

Click to expand...

I remembered your first post because I have just bought some of these LEDs. They're on their way. Having committed to modding a light, I'm concerned about how well they will perform.

So I thought I'd bump a little to encourage others to report their results. Thanks for the comments, Icebeng.

Paul

Er... oops... need to clarify 1 thing.
I sent mine off to Peak for a custom made light.

When I said mine are ok,
I meant that before sending them off,
I used 2 lithium coin cells to test them on money, etc.
I have NO idea how they'll do in a light.
Will post further when i get the lights from Peak.

Er... attowatt, what did you put your UV leds in?
Is it possible the lens is blocking the uv?

attowatt said:

These are the leds I purchased from the group buy from Chimo about 3 weeks ago. I purchased 20 of these uv leds at 360 nm.

I know this may seem strange, but my photon freedom @370nm seems to flouresce better than these @360nm. Also my $50's lite up orange with the photon, as where the GB 360nm dont even light up the $50. Even stains in the bathroom light up better using the photon freedom, as where the 360nm barely light up. Of course neither 370nm or 360nm lights up the 100 dollar bill.

Am I missing something?

I was going to put these in a cluster of 3 or 5, but now am having second thoughts.

Jim

Click to expand...

If these are the ones from Fox, the wavelength seems good but the output is low compared to the Nichia 365nm LEDs (which agrees with the datasheets from both companies). We have a regulated 39-LED module up for grabs if anyone is interested, we'll put it on our "prototypes for sale" section shortly The power is ok in their 3-chip 5mm packages, but they have 4 legs and are thus not easily substituted on the same board that takes regular 5mm LEDs.

Piers!

Another thing to note is the 360nm is the peak, and it has a very narrow bandwidth. That means it doesn't spill over into 350nm, or 370nm/380nm much at all. Most light is 360, then it drops off quite steep after that.

There is a chance that some things flourece better at a certain frequency only. Meaning 360nm might be too low for that particular thing to glow.

They are going to make a 3 die package 2 lead version sometime I was told.

The 360nm UVA LEDs have an output of approximately 0.315mW (315µW) at 360nm.

I have similar experience as well. It doesn't impress me at all and have discussed it in https://www.candlepowerforums.com/threads/94491

ernest

Craig yup, not a lot of output, that's why I'm using 19 of them in a light I plan to mod tonight. I think they do good in a dorcy1aaa though, it has to be dark to see a lot but it is effective. For the cost over the nichia it's a fair trade off.

i have some Nichia 365 and they blow these out of the water.... 6 dollars a pop, but you pay for what you get.. nichia's are glass domed.. fox output is killed by its dome, i ground one down and got a little more out of it..

icebeng said:

Er... attowatt, what did you put your UV leds in?
Is it possible the lens is blocking the uv?

Click to expand...

Nope... I have them bare connected with alligator clips to a variable power supply 0-12 volts and 0 to 5 amp... unless :thinking: the 5mm package blocks the uv?

As some others have stated here, I feel better now knowing that they only are putting out 315u watts.

xenopus: these are the fox type i believe.

The_LED_Museum: thanks Craig for the power out specs.

vacuum3d: thanks for the thread. exactly...I am in no way saying that the GB was bad. I am grateful to Chimo for orchestrating this and appreciate his efforts, trust me I know what its like trying to ship out packages to people here, as was done with my dorcy aaa tailstand caps. I just feel these leds are WEAK.

I wanted to use these in a coast led lenser that would require5 uv leds, but dont feel that will be bright enough for my application.

Anyone know where i can get 360nm _370nm leds that ARE similar to the uv led that is on the photon freedom?

Jim

nemul said:

fox output is killed by its dome, i ground one down and got a little more out of it..

Click to expand...

HAHAHAHAHAHA

I guess i was right in my statemnet earlier