ALL GONE...Free High Power UV LEDs.

33 posts / 0 new
Last post
Scientist's picture
Last seen: 1 day 17 hours ago
Joined: 07/24/2017 - 13:33
Posts: 351
Location: Out standing in my field NY

I was lucky enough to snag one of the Sofirn SC31B’s when they were offered last fall and I put one of these emitters in it. You are right Matt, these are really powerful. It was easy enough to get the (glued) bezel off with a strap wrench and the new board that Matt supplied fit right in.
The cross on the emitter will make a donut hole in the beam unless you fiddle with the reflector height. By unscrewing the bezel I can get a relatively uniform beam with the OP reflector. One of these days I will try to come up with a good collar for the emitter spacing.

Some minerals fluoresce great with this, my primary interest. Most studies of fluorescence in minerals have been done at shorter wavelengths (254 and 365nm) so there isn’t much information on what this wavelength is good for (yet!).

This is some hexagonite I collected in upstate NY. You can’t use the usual ZWB2 filter at this wavelength unless you really want to cut down on intensity so I am using without filter. The blue glow you see is from the extra visible light at this longer wavelength. If this bothers you, wear some yellow filter glasses. I got some at the local auto parts store that came in a kit with a little 395nm penlight and a bottle of leak check fluid. I would strongly advise wearing filter glasses when using this emitter as all kinds of surfaces reflect the light and can cause eye damage quickly. I am finding that this longer wavelength is most effective for organic materials, so the leak detector solution really is bright. Things like paraffin and gasoline fluoresce well also. I hope to try this outside once the snow melts.
Matt is concerned that this emitter might not take too much current. On my tail cap measurements I got a value of 1.5A on high but this was done using a DMM (Sofirn supplied battery). Others using a clamp meter said they got more like 3A. I have not seen any ill effect of this high current with this apparently sturdy emitter. What about heat? The graph below shows the temperature of my light on high. It appears that the driver has a timed step down starting at about 3 minutes and this keeps the head of the light below 40C. I superimposed measurements derived from the video Funtastic posted in a thread about this light to show when the stepdown occurs. I tried measuring the intensity changes of my light with my tablet. I do see a stepdown occurring at the same time but I don’t think my method was recording the change of intensity accurately. So this seems like a great light to use for this high powered emitter. Even without Sofirn offering a big discount it is a very affordable light. Thanks again for your generosity in distributing these vestureofblood.

Please illuminate responsibly
Part time fragmented conciousness technician

UV triple using Sofirn C8F
395nm High Power LED in Sofirn SC31b

Last seen: 23 hours 48 min ago
Joined: 05/19/2017 - 18:52
Posts: 3659
Location: US

I think if you reamed out the reflector to a fairly common diameter you could find plenty of 5050 centering rings to try. Some people use drill bits, hand drill reamers, or even a blade from scissors to do it. YMMV