Im looking for info on modifying Convoys FC40 driver to 18v-19v at around 2.0-2.3 amps. Or any of the other 6v versions.
My plan is to put this in a S2+ with three B35AM leds in series. I already have the MCPCBs. Im finding lots of info on the H1 drivers but they seem to not be available anymore.
I will eventually need to learn how to make a custom MCPCB for a quad B35AM at that point i could use more available drivers.
This doesn’t answer your question but if I’m right this would be a better solution.
I believe this triple MCPCB will support the B35AM:
And you could use the Convoy 6v 5A driver:
That seems like a great solution, thanks!
The triple pad seems a little unusual, it might take a couple tries to get the optics to light up.
It’s nice of you to join us, JoeDirte!
I remember David Spade used to have a late night talk show called Lights Out with David Spade.
It was extremely funny, but short-lived.
That is a legitimate concern, since the B35AM has a symmetric footprint, while the Optisolis board is asymmetric and has less thermal contact area. With the centering issue and poor thermal contact (and known sensitivity/fragility of B35AM), 3x519A under a good (10507/8) optic might be a better solution in every way, unless you are set on 6500K, which the 519A does not offer.
What triple MCPCBs have you found for the B35AM? This seems like a v interesting mod
Thanks, I was wondering how long it would take for someone to get the reference! 
The coverage is so close though! I bought a couple to try out.
My only concern with the 519a is everyone does it. The B35AM in a triple configuration has a lumen output close to or more than that of a single high CRI XHP50.3. With the 6v 5a buck you’re looking around 2500 lumens, with the triple B35AM you’re looking at closer to 3100-3300 lumens with a better CRI.
The 519a your looking at 2100 lumens de-domed and 2700 domed in a triple with the same 30 watt driver. The N1 version seems closer to the B35AM.
Just looking for a every day carry 4000k high CRI light. I did buy a couple boards out of France for the 119 LED, its wired in series though. I ended up revering the polarity of the middle B35AM and exposing the traces to run in parallel. It seemed to work great with a 4amp driver. The shipping was horrible and I had to modify it for the traces and TIR lens. Ill post some pictures when I get it together a little more. It would look nicer if I could have ran it at 18-19v.
The MCPCB https://led-mounting-bases.com/en/star/278-star-mcpcb-for-3-leds-nichia-119.html
Edit, If I could find four of the 519a-N1’s I would be looking at near the efficiency of the B35AM. Estimated 3400 Lumens with the N1 if you keep the domes under the TIR.
Ill warn you, the shipping was A LOT! Its also wired in series.
https://led-mounting-bases.com/en/star/278-star-mcpcb-for-3-leds-nichia-119.html
Got everything installed and working. I lapped the MCPCB and the pills, hopefully this helps with longevity. I used some flat diamond stones working from 400 to 2500 grit, then to brown paper and polishing compound. Not perfect but its flat! Kinda ugly but the middle LED is reversed and I exposed the traces requiring an extra pair of wires.
The Lumen Craft MCPCB is a lot higher quality, it didn’t require much for lapping. I scraped the coating in the corners where the footprint was smaller. The led lines up really close to the TIR lens just slightly off center. I filed the edges of the post slightly so the TIR can rotate slightly. When you tighten the pill in it wants to rotate the correct direction and lines up perfectly.
Oddly enough I was thinking about your comment the other day…
Still using the Optisolis board I modified for the B35AMs so far working great! I put together a triple 519A light as well to compare.
B35AM 4,000k, Convoy S2+, 6v 5a boost driver, 10511 optic
519A Domed 4,000k, Convoy S2+, 3v 8a buck, 10507 optic
Using my phone and a light box the 519A light produced a higher Lux. Out the front of the light diffuser on the camera lens the B35AM produced more lux.
So for anyone following, your statement is 100% correct for my application a 519A is more suitable. The more efficient 10507 optic makes a perfect large spot/flood beam with the domed emitter!
I have some FFL351A emiiters that look good on the bench with the 10507 optic that I plan on trying out.
The rings tint shift in reference to my pictures are not visible with the eye.
Thank you for the update! Extremely impressive that you managed to make this PCB work for B35AM.
The FFL351A might be able to put out even more light through the 10507. One thing about TIRs (which I realized I didn’t mention), as compared to reflectors, is that the transmission efficiency is dependent on the size of the light-emitting surface (LES). Part of B35AM’s inefficiency through this setup is that its LES is so large that a great proportion of emitted light ends up uncollimated, lost within the flashlight before having a chance to get out. The FFL has a even smaller LES than 519A, and thus should have higher transmission efficiency. There might be some starburst artifact though.
Interesting beamshots, it is clear that the camera doesn’t know how to handle high dynamic range that vary continuously, hence the discrete ring artifacts. On the other hand, I know that there is some petal-like 3-fold-symmetric artifact in the spill, in the 519A beamshot, that the camera is failing to capture.
Regarding using Convoy driver for 3 6V leds in series: If I remember right the boost converter used in Convoy’s boost drivers has max output voltage of 16V. So not an possible option. They use MP3431 boost converter.
Yeah, I ended up going a different route when I realized that was unrealistic.
The aluminum MCPCB couldn’t handle the heat, it would smoke, no visible damage though… The copper MCPCB was a really easy mod, just scraped a little of the coating off with the tip of a razor blade. It seems to be a lot higher quality probably why im getting away with it.
I will probably stick with single B35AMs, most of the 5050 TIRs ive tested work really well with a slightly tighter beam than advertised.
Good info on the Fireflys! I was hesitant thinking they were too rosy from the pictures online. Bought a few to test and in person they really look great!
I am curious, how are you getting around the centering issues with fitting a 3.65mm LED in a 5050 TIR? Or is the TIR so diffusive that it doesn’t matter? I do find that Convoy’s clear narrow 5050 TIR is an amazingly well-designed one, it can blend even the worst tint shift from SST40 without losing any throw for its diameter.
Convoy has a small round gasket that fits the B35AM, most of the time I just center it the best I can if I dont have one that fits. Reflectors seem to not matter as much, I dont use a gasket with those.
Interesting, a 7mm diameter suggests that it is designed for 7mm reflector hole, which corresponds to the diagonal of a 5050 LED. But the only 5050 TIR I’ve used has a square opening for the LED, which wouldn’t fit this gasket. Which TIR are you using?
