I definitely want to know it’s max capability is but i meant what host is it going in, what torch are you going to build with it?
Very nice 
.
2 questions :
Where do you get your brass button ?
Do you get flickering at very low current, <100uA (I mentionned it in my thread)
Awesome! That’s a lot of power in a 17mm driver.
Yeah, brass buttons seems to be the way on crowded drivers. And I agree, 17mm opens up a ton of host options. I think if I want to start putting brass buttons on anything, I’m gonna have to buy a brass rod and cut them to length myself.
How can this be configured for a maximum output current, for example if one intended to use it with XHP35.2 HI?
When you settle on a final design, oshpark and BOM would be awesome!
Ahh, with “in” I though in current 
I will make some pocket rockets out of some old Convoy S2 and M2 hosts, and I have a bunch of Brynite B158B hosts which have custom pills for wider zoom (Build/Mod: Zoomie with Brynite B158B host (wider flood mod)). I plan on building B158B with these drivers configured for 12V and use XHP35 HIs in them, I think I have four of those LEDs laying around somewhere.
I’ve had them for so long, sorry I don’t remember. It could have been intl-outdoor.com but if so they are no longer in stock. I’ve bought so many small bits and bobs over the years, I don’t remember where I got all this stuff from.
With my MP3431 version I don’t get visible flickering. I use it ultrasonic mode, I haven’t tested the other modes (not automatic). Loneoceans used this mode so I just went with it on mine too.
I didn’t get much testing time with my TPS version before I popped it by shorting LED cables. I have not built another one yet but I will soon enough, I can report my results.
Oh yeah good idea.
We should ask Simon/Convoy to offer the brass buttons in his store. I’m sure he can find a cheap source.
Congrats Mike! Great works as always!
Yes USM is better for this, as current decreases it decreases the frequency until 20KHz after that it uses forced conduction mode if the current decreases further, the efficiency is not as good at low loads but there is no issue with flicker, also no risk of audible noise (as the name implies)
My firmware has a configurable max amp setting. It can be programmed when flashing the firmware or it can be entered by config menus with a bunch of clicking. Unfortunately the current accuracy is a little less with the HDR FET, it changes it’s resistance a little, but I think it will be good enough. If very low(moon) modes are not wanted, then the HDR FET doesn’t have to be mounted, and the high power sense resistor can be placed in the low/moon sense resistor’s position. Current control by firmware will be more accurate then. There is a possibility to limit it by resistors, but I don’t think that’s very flexible if the LED should be replaced with something newer later on.
I’ll build another TPS61288 based version and fully test it. If it has flickering like thefreeman reported, then I’ll for sure stick with the MP3431 as it does not have this issue. I do have a bit more functionality testing on the MP3431 too, but if that all checks out it’s ready to go.
Whenever i see these drivers all i can say is amazing and how much(?)
Oh sweet. That will be fantastic. When you say less accurate, are we talking more than +/- 0.1A? I love my moonlight modes.
Do you expect any clearance issues with retaining rings? I know some of the double-sided 7135 drivers are tough in a S2+
I’m thinking of a Convoy M2 with a SFT-70 and another with a sliced Nichia 144 R9050
Why not Nichia NV4B35AM? I would think it’s better than 144A and would be glad to learn why it’s not. 
When I list the BOM I will at least be able to provide material cost.
Possibly a bit more, I have to do more testing. I also have an idea on how to eliminate the issue while having the FET but so far it’s just an idea. I have to do some research, it could be far fetched.
I just checked with a S2 host, I haven’t opened one of those in ages. The retaining ring would have to be filed out. But I noticed that the pill depth has no chance of fitting the XAL7070 inductor, darn! A lower height one would have to be used, like the XAL7030. I couldn’t find any S2+ host in my drawer although I’m sure I have one or two somewhere.
I checked with a S3, the retaining ring on those is no issue at all, plenty of clearance, but same issue with driver depth. I haven’t done any testing at all with the XAL7030 but that’s something I will have to do as I see some of my target lights won’t fit the XAL7070.
No proof yet, but I am assuming the smaller package is going to be thermally limited. I also fear they’ve used newer silicone phosphor binders that burn at low temps like the e21a and 219F etc. I really hope I’m wrong and that they can be driven to 40W+ like the 144. For anything but a max power build, I’d prefer b35a for all the reasons I chose against it.
When I designed my driver I thought of using a mux for Vsense :
That way the mosfet is taken out of the total Rsense and doesn’t interfere with it, the gate driver could even be removed.
There are small ones in SC70 package, though I haven’t looked into it much, if possible smaller would be better. I don’t know if they can interfere with the very small Voltages.
It doesn’t need a separate control signal because it can be the same as the one for Q1.
The disadvantage is that it adds one more component (obviously), also now Q1 resistance is added to the circuit and thus incurs additional conduction losses, so maybe keeping the gate driver for a lower resistance would be better.
Yeah height clearance is a problem with many hosts.
The solution I used seems to work well, even though it reduces efficiency at very low levels it’ll still be more efficient than USM at low level. But if you want that crazy output then yeah the MP3431 is a better choice.
The mux idea is what I was thinking of. I’ve never used one before but I’ve just made a V5 design and managed to squeeze one in. The one I went for is the Texas Instruments SN74LVC1G3157 because it comes in a variety of packages, two of them very small: SON (DSF) 1.00mm × 1.00mm and X2SON (DTB) 0.80mm × 1.00mm.
How it works for these low voltages I don’t know, the datasheet list of features includes “rail-to-rail signal handling” so I assume it shouldn’t be an issue. I don’t know about noise though. I haven’t found anything in the datasheet that suggests this one is a bad choice but I’m all ears. Otherwise I guess we’ll find out.
Yeah this is worth testing, especially for high current (9A lol) where the sense resistor has to be very low for a low Vsense.