Ultrafire UV 400nm to 365nm Conversion

Hi, i am really new to all of this and wondered if someone might be able to help me out. I purchased an Ultrafire WF501B to find fluorescent minerals at night, but knowing a bit more about it, i realize it must be putting out UV light around 400 nm rather than the required 365 nm. Could someone please let me know what might be involved in converting it to 365nm?

thanks...slikhead

If you want true 365nm, I'd recommend to go with Nichia NVSU233A LED and of course, you will definitely get better result with the Wood's Glass however it may be hard to find one cut at 32mm. You might be better off getting a Convoy S2 host as 20mm Wood's Glass are easily available now. Why Wood's Glass? Any and all 365nm LEDs emit good amount of purple or ghostly greenish-grey light (Nichia LEDs are a lot better, only purple light, with good amount of 365nm UV), so those visible spectral contents has to be killed before you can notice any fluorescence clearly. I went the same route as you until I found the original LED perform rather craptastic so I modded it with NVSU233A LED however the Wood's Glass of this size is too expensive so it's now my glue curer lamp (same WF-501b host). The round LED MCPCB also has to be 16mm too. Be sure to cover center pad with Kapton tape as the NVSU233A LED has two pad while the MCPCB in question has three pads, if you have to use Cree XP-G version.

BTW, I have a Nichia NVSU233A blacklight flashlight made into a Convoy S2 host along with blacklight filter installed (my icon is also a picture of this flashlight too). Really nice handle to it and rather slim too.

I would not worry about it. It is all actually about how much UV makes it through the lens. I honestly doubt you would be able to tell the difference between 365nm and 400.

I guess, the most budget "repair" would be this one with a Nichia LED. This filter is a good addition as well if you have an opportunity to disassemble a S2+ head.

CelticCross74 said:

I would not worry about it. It is all actually about how much UV makes it through the lens. I honestly doubt you would be able to tell the difference between 365nm and 400.

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It does make a big difference. Without the Wood's Glass, you can't really tell if anything really fluorescence at this point - purple light from the Nichia LED masks some fluorescence almost completely. Add the Wood's Glass (like the one vadimax posted the link to - I use exactly the same filter in my DIY NVSU233A LED flashlight), and it makes the day and night difference; at the point purple light (~400nm) is gone, everything will really light up like Christmas Tree (and it would make somebody a true clean freak immediately after looking at their house in strong 365nm UV light).

About the Nichia NVSU233A and NVSU333A (if you can really afford it), be cautious with it; those LEDs are extremely powerful ultraviolet emitter (even so more than Chinese UV LEDs which usually are quite wimpy), so invest in a good amber / yellowish UV block goggle to protect your precious eyeballs.

thanks heaps for the help, i really like the idea of switching the led for a nichia as the ultrafire WF501B barely lights up some rubies in fuchsite that i have (which really fluoresce under 365nm light).
Is it as simple as removing the old led and soldering the new one in place? or are there other electronics etc etc that i need to sort out?
cheers

Not really much. If you swap the UV LED that is of Cree XM-L footprint with NVSU233A, you will want to cover the middle pad with Kapton tape so you don't accidentally short the LED, or cook the driver. Otherwise, it's almost a switch and drop solution besides two pads (compared to 3 pads used by most Crees and some Nichia 219s). As for WF-501b, you will want to buy 16mm Cree XM-L MCPCB, and go that route as the Chinese UV LED almost assuredly use Luxeon 1 footprint - NVSU233A LED is TINY (3.5mm x 3.5mm).

As for electrical driver specification, the Nichia LEDs don't really care, as long as you don't go over 3.6 - 4.2 Volts (the LED driver takes care of that detail), however, for this UV LED, it's up to 1.4 Amps (I drive mine at 1 Amp, and it do get hot in Convoy S2 host in about 15 minutes, and it's silly bright, easily outshining the $10 4 watts blacklight fluorescent lamp). You can google NVSU233A for its datasheet.

As for availability, if you want it cheap, try to get to Nichia representative in your area (they will sell you however you want, it's $13 a pop which is a steal).

Don't you mean xpg board? Not XML?

http://www.candlepowerforums.com/vb/showthread.php?421235-Nichia-NVSU233a-Flashlight-Build

In comparison to other 395nm/405nm flashlights I've dealt with, I don't really see any purple light from this LED. I don't think you would need any Woods glass with the Nichia LED.

I'll be posting some beamshots and comparisons hopefully later today.

gunga - the XP-G and XM-L has similar footprint, I checked in datasheet for both LEDs.

MrBaz, some people has a bit more sensitivity to UV light (I can see UV, down to 365nm which looks like dim purple - it's the 380 - 400nm purple that bothers me). So, Wood's Glass is suggested for those folks.

EDITED: gunga, I have been trying to get hold of you. I hope CPF don't have problem with private messages. You should be getting those NVSU233A LEDs from me this week - if there's no problem with those, let me know as occasionally mail service can be a problem customer.

Hi there. XML is much bigger than xpg. Same footprint type but much bigger.

I got the LEDS. Thanks!

Right, XP-G is correct. Derp. Anyways, I am glad you got those LEDs in one piece.

thanks Dr Mario, i am slowly getting the idea so to convert this to a NVSU233A i need the led, and a 16mm Cree XM-G metallic core printed circuit board.

I am not sure if i need a new driver and i do which one would you recommend?

MrBaz The pics of your 395nm light show way more fluorescence than i am getting with my WF501B, its basically a pretty bright purple and I barely see any fluorescence aprt from bright yellow or pink objects.

Cant wait to have a crack at modifying my light, could you please tell me if i need any special tools to get the job done?
thanks!

MrBaz's flashlight is actually 365nm, BTW.

Yes - you just need Nichia NVSU233A-U365 LED (P6d22M bin may be a bit easier to get) and Cree XP-G board is all you need - just be sure to get some Kapton tape too, it can resist soldering heat; you will need this to cover thermal pad. Much easier to use Cree XP-G starboard (or just MCPCB) rather than attempting to find Nichia Rigel MCPCB which is impossible to find.

Awesome thanks Dr Mario. btw do you know what tools I might need to do the conversion?

Just soldering iron would suffice.

However, if you do the hard way (soldering your own ittsy bittsy LED on the MCPCB), I would suggest to use the SMD hot air reworking station or electric coffee warmer - also, soldering paste is much easier to use in this regard. I use a Butane-fueled portable blowtorch to solder the LED onto the MCPCB held in by the handy soldering helper (the flame has to be held far away from the bottom of MCPCB - hot air rises, of course - at about 4 - 6 inches between the torch tip and MCPCB, just so it only get hot enough to liquefy the solder paste without causing harms to the SMD LED), then let it cool gradually before transferring it to the heatsink, following soldering temperature profile - no problem with the Nichia NVSU233A LED soldered this way - I have it installed since March. Don't forget to cover the middle thermal pad with Kapton tape so you don't accidentally short the LED.

And, I forgot to say, now that Gunga brought this one up, BE VERY CAREFUL with the glass cover, it's silly fragile. Very thin, also. It's purpose is to protect the LED against moisture and containment.

If you accidentally broke it anyways, be sure the light engine is sealed up real well (which is easy with Convoy S2, and probably the other Convoy families - I still recommend S2 for the fact that custom blacklight filter is hard to find. It's up to you to decide, however, as noted, some peoples can actually see ultraviolet light in the 400 - 380 nm spectrum, and I can see much further into probably 363nm which is seen as very faint harsh purple, and I had to use filter to remove annoying purple hues in around 400 - 374nm spectral block).

Yep. Darn fragile. I find the purple rather distracting so the zwb2 filter is a must!