I’ve been waiting this for too long! Thanks for bringing this 17mm high current capable buck driver to us Richard! 
I am waiting for the release of the 6A version for my 1405… and nope, I’m not gonna build this driver by myself but I will order one from mtnelectronics directly. I hope you will offer them as a complete driver in the future Richard. 
Ordered, along with one of those mmu programming boards.
Still looking forward to your other versions. This is good stuff Richard.
Richard does sell a 20mm 6 volt 3 amp buck driver. I bought one to try on a XHP50 upgrade on one of my lights that can’t take the heat of a fet driver. Also I was too lazy to zener mod a 105E driver. :bigsmile:
LD-2D 2 or 3 Cell Driver - 20mm - For 6V LEDs - 3A
At this point in my life I think I'm about ready to be done with school! I have a biology degree where I did learn a little bit about basic electronics in physics, and now I'm finishing up law school. I did consider going back afterwards to get an EE degree or CS degree because those are very desirable in the patent law field, but after I decided not to pursue patent law I decided not to go back.
Besides, I just do this stuff mainly because I enjoy doing it. I don't know if I'd enjoy it as much if it were a "real job". I'm sure that a real EE would just laugh at some of my attempts, because these drivers are really simple compared to some of the products we use every day. I design these drivers at lunch time and when I get a few spare minutes, so I usually move pretty slow.
crap! we need an EU warehouse!!!
thanks Richard. I appreciate you putting this out there for the BLF community. Ordered the boards and the MMU breakout board that pilotdog reminded me of!!
+1 :party:
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OSH spamers 
subscribed and waiting on the higher amperage one also! Kudos to Richard for this fantastic resource. Wonderful vendor.
cant wait for other versions! twenty and 22 mm versions would be cool
For 20~22mm size we already have the LD-29 (about 21mm) which is capable to handle and deliver high current.
i need more than 3a though. 6a would be good. or more
I wouldn't recommend using this with a contact board, as it relies on having a direct thermal path between the ground ring and the pill, either by use of a retaining ring or solder to transfer the heat from the driver. Any intermediate piece, especially another PCB, will limit the transfer to some extent.
Looks great RMM. You know much more about this stuff than me. So I apologize if this is a dumb suggestion. I find that the fly back diode to be a limiting factor in some buck drivers. Maybe the inductor size you are limited to space wise is more of a bottleneck, but it looks like you have room to add a parallel to D1.
Extreme high power isn't the point of this board. An extremely low profile along with programmability and reliability was the design goal; the other board (still to be released) is for higher power.
In a small SMD inductor there is a lot of resistance, and with that resistance comes a lot of heat at high currents. You also have to deal with core saturation on a small inductor like this, although it would tolerate 5A-6A. That is why there is two versions of the board: one for low-profile applications, and another that is for pills with a bit more room for an external inductor that can run more current due to its lower resistance and getting the heat away from the board (and also has a bigger diode). I didn't stick a huge diode on here because it simply isn't needed for what my design goal was (3.5A-4A), is smaller, and is less than half the price of a bigger diode.
Would a copper ring soldered to the annular ring be ok?
Would a copper ring soldered to the annular ring be ok?
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I'm sure it would be. That said, if you're patient you'll get a 20mm soon that can do 5A+ with a bigger inductor and diode on board. It will also be slightly more efficient due to the slightly bigger inductor, so if you want to do 20mm I'd wait.
BTW, I am currently testing a few different 17mm revisions setup for more power, but I don't generally release anything that I haven't personally built and tested. I don't have time to support and post on many "WIP" types of threads. The general rule is that if I've shared it, it's actually been built and tested. It doesn't mean it will be perfect, but that if properly built it will work.
If you want maximum performance and efficiency you really need a Coilcraft inductor (XAL series). Their small inductors blow away everything else in similarly sized packages. They are almost three times the price of an Abracon or Bourns, but if you really want a 5A+ 17mm driver with an SMD inductor, I think it's the only way to go.
I ordered from OshPark today so I threw three of these in my cart as well
Also placed an order with RMM today. Richard, please check my note and get back to me if there is a problem with the resistors I’m using.