17mm & 20/26/27mm single-sided DD/FET driver release: A17DD-SO8 / A20DD-SO8 / etc

Hard to say since there is no graph corresponding to fig 8 showing Rds-on as a function of gate voltage. It’s not just how low the resistance is but how much voltage needs to be applied to the gate to get that low number. My guess is it’s pretty good but that would be just a guess based on what the graphs usually look like. Things like thick wires, spring, and switch mods will likely have greater impact at this point. Also paying particular attention to electro mechanical connections like threads and rings is important.

I’m using windows 10 Tech Preview, 64bit, and everything worked thus far. The only Issue i had was with installing the Usbasp drivers, for that you would have to disable the driver signature enforcement , Pretty sure you’ll have to do that with windows 8 PC as well.

Disable driver signature enforcement Win 8/8.1/10
http://answers.microsoft.com/en-us/insider/forum/insider_wintp-insider_devices/how-do-i-disable-driver-signature-enforcement-win/a53ec7ca-bdd3-4f39-a3af-3bd92336d248

Yeah i agree i would think if there is any more improvement to be had from better MOSFET’s it is in under a 1% more output from a single battery single led application and more can be gained by those resistance lowering tune ups you mentioned, but it is still possible some more to be had when they release it and that is always nice :slight_smile:

I know i will keep my eyes open for it when i buy some more stuff from the regular suppliers like farnell in the future.

I’m not the guy to say “don’t try it”, by all means give it a go. Just don’t expect much difference if that’s the only change made.

I need some help regarding the component BOM.

I’m seeing a 221 resistor in the photo in the first post on the spot with the triangle silkscreen. Is that correct or should it be a normal diode?

The other thing is the SOD-323 is for the zener position and only used if I want a zener build right?

Its the opposite , You need to replace the SOD-323 diode with 221 resistor when using zener.

Thanks sinner, that makes sense to have the resistor in series with the zener diode. Also, I realised that I missed out the portion on D1/R3 in the first post which explains the same thing.

I’m not sure about tips on programming in general, but I’ve collected and published several firmwares in one place for convenience (including source when possible). The link is in my signature.

I’ve been trying to collect as many as I can there, but I’m pretty sure I’ve missed some, and a few are still on my todo list.

10x ToyKeeper , quite a collection!
Can i contact you later for some details? Especialy for thet BLF17dd driver

Umm… sure?

I just added several more firmwares too, since I had a few on my todo list. And I’m pondering ways to tag the firmwares with relevant hardware requirements, to help people navigate the collection. Like, this one requires an e-switch, that one requires an off-time capacitor, etc.

I had another go at the 17DD single-sided V024 with zener mod, and succeeded this time :-) I used a MCU from a AK-47-A driver, so it is 5%-25%-100%, with on-time memory, not the greatest UI but it is what I had. I used it for a Convoy S8 mod with a XHP50. In the end I think I crushed one of the 18350 batteries resulting in halving the output :-( , but it was close to 2000 lumen at first. I ordered new batteries to see if that was what happened.

board soldered onto the pill.

short brass pillar for batt+, space was tight in the battery tube with 2x18350's.

there you go:

I posted two beamshots in OL's XHP50/70 beamshot thread, but I still have to do tweaks to the focussing, it can become better than that.

Thanks for updating us djozz. It seemed safe to assume that you wouldn’t have any additional problems after those last learning experiences. I’m glad this one went together without issue.

I must admit… I love the gaudy, saturated look the gold plating takes on in your photos. :slight_smile:

Odd about crushing the cell. I’ve never squished one that badly, as far as I know. I’ve only dented the end about 0.5mm or probably a little more.

I’m way behind on that thread. (133 posts behind…)

is the PSMN2R4-30YLDX still the best candidate? or is there a better option now?

Also, when I’m ordering diodes for D1, there are a lot of specifications, but which ones am I actually looking for?

I don’t remember any discussion on the PSMN2R4-30YLDX, and i can’t find anything on this when i search BLF.

But the PSMN0R9-30YLD or the SIR800DP-T1-GE3 i believe is considered to be the possible higher performing than the usual PSMN3R0-30YLD from the OP.

EDIT
Do you mean the smaller LFPAK33 PSMN2R4-30MLD when you say PSMN2R4-30YLDX?

PSMN2R4-30YLDX

Yeah i found it on google also when i searched on it, but you said “still the best candidate” implying that this was common knowledge that it was, thats how i read it anyway.

When i compare the fig.8 “Drain-source on-state resistance” in the data sheet i think the PSMN0R9-30YLD looks much better.

I assumed it was highly regarded at one point because it’s what mtn sells.

Ok thats interesting, then i am also curious why :slight_smile:

I hope some of usual MOSFET gurus here can chime in, or maybe RMM himself.

In a Zener modded board the gate voltage will never fall below 4V so it should be fine. It’s possible that one with better fig.8 numbers might be better for single cell DD but not enough builds with other options to know if it’s worth it to spend $5 a piece for them.

  • I think that figure 10 is the most telling when comparing those two FETs. By my reading of figure 10 PSMN3R0-30YLD is clearly superior to PSMN2R4-30YLD. (When scrutinizing the datasheet this difference is first noticeable in figure 7, but it’s not clear why… figure 10 shows why.) Both MOSFETs are suitable for use with this driver. Since PSMN3R0-30YLD is less expensive and appears to be the better of the two I’ll continue to recommend it.
  • I think that DBCstm has decided to go with SiR800DP for future builds, although I know he’s got a few other FETs on hand at the moment such as the very expensive Toshiba units. I don’t think I’ve seen a side-by-side, but it’s always seemed pretty clear that the SiR800DP would firmly beat the PSMN3R0-30YLD. [compare “On-Resistance vs. Drain Current and Gate Voltage” in the SiR800DP datasheet with Fig10 in the NXP datasheets] SiR800DP also costs over double vs PSMN3R0-30YLD. I doubt that most folks will gain a lot by spending the extra.