I have the Convoy S2+ Nichia UV and found the single mode limiting. Is it possible to have it work with more modes?
I own a Convoy S2+ Nichia UV light, but it is a few years old now, and I don’t know if it has changed much in the meantime. My light has a single mode driverboard with two (2) advanced current regulators, also known as AMC7135. General opinion is that this 700mA configuration is more or less the limit the (my) Nichia UV led can handle.
It certainly is NOT the most potent UV light in my posession. I would not go for a driver with multiple modes that (as a rule) are less than 100%. And IF you should buy such a driver, I would advise to limit (cull) the amount of regulators to the same number as on your current driver.
The Nichia UV light I have is this one, 3x7135. In my understanding, it will be fine if I use any 3x7135 multi-mode driver, but I’ve asked Simon if I can switch the driver and his response was “Sorry, it cannot be customized.” Any ideas as to why that is?
Convoy has four 3x7135 multi-mode drivers, here here here and here. What would the problem be if I used any of these?
I’ve read the link you provided and it says this light runs on 700mA. That’s 2*AMC7135 (the 35 stands for 350mA/pc, there are also 380mA AMC’s, AKA AMC7138). On your own risk, I would take THIS ONE. because you can chance the mode menu the old hardware way. By soldering the star of your favourite mode choice to the ground ring. AFTER you remove (desolder) one of three present AMC’s, of course
Seems I have my own product page. In (pidgin)Dutch. In German it also says 700mA.
Sorry for the slow reaction, but first I checked your version (of course 
)
And then I had quite some trouble getting it back into the “Dutch” version.
I guess the only way to get to the bottom of this is to loosen the retaining ring of the driver, trying not to tear the leads, and try to count the number of regulators.
Yes, any of those would work fine. When I modded my last, he didn’t have all of these 3x drivers in stock, so I just removed one 7135 chip from the 4x Biscotti driver. Works great, much more useful for me with the 5-mode group option (the equivalent now would be his 12-mode driver…same thing with modified firmware from the old original Biscotti that TK developed for him).
You don’t want to overdrive the Nichia uv emitters like we do with our white emitters. All uv are more sensitive to heat and derate quickly but the Nichia are a little less robust than the ones from Seoul and LG. At 700mA they are already overdriven a little from the official datasheet 500mA max. I think if you only run the light on high for brief periods…like brief checks or a short photo session before turning off to cool, it’s fine with the 3x chips. Even though the high Vf and battery drain kind of self-limit these lights quickly, if you want to run it on high for longer periods then it’s better to go with one of those other two emitters which have proven to take more current safely.
Simon may have interpreted your question to be one of having him custom mod the light for you before shipping. He used to do that pretty freely and usually for free, but he’s quite busy now and maybe wishes to reduce the special one-off services like that (maybe?). It seems that he’s more willing with simple swaps like reflectors but it also seems that it depends on the particular light model (could be due to stock location or who knows). He also may be reluctant to alter anything from stock for sale to US customers because of that dumb patent thing, which he respects and has complied with.
There’s nothing special about the driver other than limiting the current to appropriately-wimpy levels, so you could also use something from Mountain Electronics or another driver of your choice that’s made for simple clicky switches. Also keep in mind that the straight math of x number of 350-380mA chips isn’t what you actually get out of the emitter…usually a bit less than that after electrical losses…so 1050mA from 3 7135 chips may seem like too much on paper but in practice the Nichia does ok with that and the actual power it’s receiving, just a bit on the edge of acceptable, however.
Is the original single-mode driver buck/boost or linear and are the multi-mode drivers I’ve listed buck/boost or linear? Seems like linear drivers don’t work well with UV LEDs.
My original is a Nanjg 111 linear driver. Kaidomain has it with 1,2,3 and 4xAMC7135.
How do you tell if a driver is buck/boost or linear? Is there any visual indication?
Just plain jane 7135 current-limiting linear. They work fine. A fancier regulated driver can give steadier output just like with white emitters, or especially if you want to run 2S batteries. UV leds are just finicky critters, requiring a bit higher Vf and also suffering from reduced output due to heat, which generally starts right away (derating). All of them are like that. So limiting their current, trying to keep them cool, and perhaps using a more sophisticated driver are the best approaches, especially in small thin metal hosts like this, but that doesn’t mean they aren’t perfectly functional and useful with basic drivers. If you do need better sustained output for some reason, then yes, you should consider a different driver. In practical use for most people the 7135 drivers are fine and decent cells will rebound nicely enough between sessions that you don’t see really fast decrease in light as you do in a typical test run/graph where the light is just run continuously.
For a buck/boost/buck-boost driver you will see a prominently raised puck component on the board…sometimes with copper windings visible, sometimes not, could be a round ring or a dark square. It’s an inductor.
This wiki site is a bit dated but lots of good basic info on it and most of it is still as relevant today as it was years ago. Here are some quick comparison pics of simple driver types…the inductor on the last boost driver photo is kind of mid-school…can still find old-school iron-donut copper types but most these days use discrete smd packages.
http://flashlightwiki.com/Driver
In this driver, the inductor is the “gigantic” square marked C103: https://www.mtnelectronics.com/index.php?route=product/product&path=67_115&product_id=554
I successfully modded my UV S2+.
Driver: switched from 2x7135 1 mode to 3x7135 12 groups
LED: switched from Nichia NCSU276A to Seoul Z5-CUN66A1G (more than doubled brightness)
Reflector: switched from 5 mm hole OP to 7 mm hole OP (much better beam pattern)
Thermal paste: switched to Arctic MX-4
3 Thanks