Buck and Boost Drivers, Testing, Modding, and Discussion (Pic Heavy)

The thing I dislike about 12V XHP50/70 is that on all the DTP boards I have seen, the thermal pad is no longer isolated, and sits at the 6V midpoint of the series chain.

Most lights have the battery negative connected to the flashlight body, so if the thermal pad is not isolated, and the board is DTP, we need to worry about isolating the MCPCB from the flashlight body which can be a pain.

It can be alright if you use good isolated thermal pads (expensive), but wonā€™t ever be as good as proper thermal paste or soldering. Thatā€™s why I donā€™t like running the XHP50 or XHP70 at 12V. Yes the problem of isolation can be solved, but there are very few benefits of running in 12V mode for flasglights so it makes it not worth it for me to worry about the isolation.

I was to get one, but finally went the XHP35 way. In case anyone is interested: Sinkpad XHP70 21mm Copper 12V or 6V @ LEDDNA

Ordered from LEDDNA once, the shipment took more than a couple months to arrive home.

By the way, ordered an H2-C, an XHP35 HI C2 3000K CRI85+ (according to datasheet), and a 4-pack of high drain Aspire 18350 1100mAh cells. For the ThorFire TA13, right. Gonna be a handsome aspherical thrower.

I am to mount an additional R100 on the sense resistor stack. This means 2.25A on turbo stepdown to 1.5A. How much effective throw is to be expected from it fellows?

What is the effective diameter of the lens?

Luminance measurements of an XHP-35 HI LED can be found here.

You can use the 12v Sink Pad no isolation needed! :+1:

Wasnā€™t aware a board like that existed. Adds some extra series resistance but probably not too bad. Thanks!

So I somehow managed to break the UI on an H1-A today. One of the new ones I got yesterday from KD. I put it in an M2 quad host running 2S2P XPG3s.

Funny part is that this is the least modded driver I have, all I did to it was bypass the spring with solder braid, replace the stock output wires for 22AWG, and file the edge of the ground ring a little bit. Stock sense resistor and stock output voltage.

The boost converter is still working since the light turns on. I just only have one mode, which seems to be maybe 40% - 60% power. Definitely not full power as the light can run for a long time without getting hot.

Iā€™ll pull it apart when I get a chance to investigate, for now it is at least a useable light.

How is that copper braid bypass working for you?

I kept burning through it on my L6.

Iā€™ve never had a problem with mine, but I run 2 pieces in parallel. (really just one piece folded in half)

I tried that as well and it still burned through. It was only pulling 12 amps at the time. Now that Iā€™m pulling 17 amps I switched to regular wire. So far so good.

So my driver fixed itself overnight. It didnā€™t work when I used it last night, it sat untouched on my desk for about 24 hours, just picked it up and it works fine now.

Lol, very true, I still plan to take it back apart, for now it serves itā€™s purpose as my desk light though.

Were you able to machine a shelf into the pill? The pill barely seems wide enough. FWIW an Eagle Eye A6 can also (with a little work) accommodate an H1-A and still use its retaining ring ā€” which is a plus when it comes time to flash the driver.

Iā€™ve managed to flash an H1-A with a home made programmer (based on a Raspberry Pi). Iā€™m curious if the PICKIT programmers can use target power with the H1-A? In other words, is the 2.5V (or whatever the PIC is provided) enough for the PICKITā€™s buffers to operate?

Iā€™ve severely abused one H1-A in particular and itā€™s still alive and well.

Got two ThorFire TA13s powered with H2-Cs and the aforementioned XHP35 HI C2 30G leds. Nice builds, I've decided not to ramp up the current, heck, emitters already reach ā‰ˆ125Ā°C on turbo (1.5A driving current, temperature measured directly in front of the emitter with infrared thermometer). Of course, the hosts get hot but still manageable (my friends don't exactly think so but that's to be expected).

I also like the mode spacing: Ć¼ber-low, low, medium and turbo/high.

What I really like is its high efficiency when going 2S input to 4S emitter, this should result in being able to drive XHP70/XHP70.2s at a quite high amount of power (mounted in 12V DTP SinkPADs). Of course, just speculatingā€¦

The MP3428 chip on H2-C is rated for almost 20A input, the main letdown is the need for external rectifier FET and the poor board layout for the ground.

I have many more drivers on my bench right now including FX35 and a Kaidomain 25mm buck-boost. Just been busy with work and planning a wedding.

Also working with another member to get an MP3431 driver developed. 21A input current could be fun. Output voltage on MP3431 is well suited to both 12V and 6V also.

Big part of why I am such a fan of boost drivers is this right here.

This is my latest S2+ triple, running in series with an H1-A Boost driver. Because it is in series the current is the same in all emitters regardless of the Vf. This allows us to freely mix emitters.

So I put a 219B SW40 R9080, 319AT SM355 R8000, and XP-G3 3000k 90+ together. 3 very different emitters, and yet they all work. The blended tint is really quite nice and is somewhere around the 3500k mark. Add

Interesting. I thought the H1-A didnā€™t output high enough voltage for three 3V emitters in series. I should get one too then.

It doesnā€™t as they come straight from KD, but if you change the 47k FB resistor to a 75k, it does it without issue. Been running a few 3S triples this way for a couple of months now with no problems. Still very efficient too.