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

WELCOME BACK WIGHT! Maybe you already know this, but you invented the greatest flashlight driver since the 7135 based driver, and this one is a land slide better!! Thank you..



borked,

The main advantage of this driver is that there is basically no real limit to the current on this driver.

For example many budget lights come with a Nanjg 105C driver you may have seen similar to this.
http://asflashlights.com/en/-diy-parts/34-3000ma-led-driver-board-custom-modes.html

Those drivers are linear, but they have maximum output based on how many of those 3 legged chips are on the board. This one has a 3000ma.

Replacing that board with one of wights FET drivers would allow you to drive the LED much harder. Say for example an XM-L2 emitter driven by an IMR 18650. With the old driver 3000ma is all you will ever get. But since the FET has not current limiter your drive current will be based on the VF of your emitter. Typically with that set up you can expect roughly around 4 amps or so with a U4 1C emitter.

Thanks vob!

Just for the record, I didn’t invent this driver and neither did anyone else on BLF. This driver is merely an evolution/re-imagining of the ones worked on by the original BLF17DD crew. That driver was basically an improved copy of the Chinese “East-092” driver made with the goals of higher current and Nanjg-105c firmware compatibility. With that said, I think it was a big improvement.

At some point I need to revamp the OP. I reserved a post under it, so there’s a place to move the old content… the actual OP needs to reflect the current state of things better: advice on using a larger C1 for high-power builds, using v044 for Zener builds, etc. It’s probably time for v024 to come out of the OP as well. It’s probably my favorite in terms of looks, so it pains me a bit to relegate it to the “post #2 reserved / old content” area.

Time for me to build some drivers!!!

I just need some more info….
Would the v024 pcb work ?
What capacitor should i choose for C1 and what diode for D1?

I’m not going to build the “zener version”

So how do you regulate the power in order not to pop a led?
Please be gentle upon me, as I know SFA electronics wise, yet am interested in it and trying to learn.

@borked: Just curious...

What's up with your signature? :)




The most important thing is to heat sink the emitter correctly. To use the FET driver a copper DTP mcpcb like a Sinkpad or noctigon is a must. You also need to make sure there is a good thermal path between the MCPCB and your heat sink.

Other than that you just have to know what the approximate vf of your emitter is. Most of the common flashlight LEDs can be run on either one or two li-ion cells.

An 18650 or 26650 for example would direct drive a XML2, XPG2, XP-L, or XP-L HI just fine. If you want to use 2 cells in series with the zener modded FET driver you can power an XHP-50 or XHP-70 that way. Since these builds will have a high drive current you need to make sure the batteries you use are well up to the task. Especially in the XHP-50/70 builds.

Looks like Posts #36 & #38 have parts list links.

You can get better diodes for D1 than what I listed in the BOM. Somewhere on this forum I think I posted guidelines for selecting the best diodes. I apologize, but I don’t currently remember exactly what specs to look for - I’ve had a long hiatus and that knowledge is out the window for now. I suppose you need voltage tolerance of around 2x your supply voltage and you need the lowest possible Vf for the diode, plus at least a few mA of current handling. Say 20mA+? If you really want to get into that stuff someone else will chime in for now.

Note that the 22k resistors I recommended in those BOMs may not be the greatest idea in the world. Toykeeper shared some test results in post #552 demonstrating that the 19.1k resistors were much better. RMM confirmed in post #564 that for 1s use especially it’s really important to use 19.1k rather than 22k. Either way the firmware should be properly tuned to get good LVC. ToyKeeper provides a test firmware for doing the calibration. If you keep reading a few more posts from the ones I’ve just mentioned, TK will bring up calibration procedures herself.

As far as board versions… v024 works for your application. You may also want to look at v044 - I don’t think I’ve built that version myself but it sounds like others have built enough of them.

I don’t have one, do I ?

With the 7135’s, you could stack to control what was fed to the LED, be it a pocket rocket, or an EDC.
Am I reading right, that this driver does not have the capability to control the input?

You appear to have multiple blank lines as your signature. Either that or it’s a picture of a snowman in a blizzard.

You do! :D

It's a 1 x 1 pixel gif stretched out to 600 x 185 pixels.

Here it is highlighted in blue:

I use this exactly this for D1.
If you can not buy from this source search for “RoHm 0.5A/20V Schottky SOD-323, RB551V-30 TE17” on eBay or Aliexpress.

For C1 I use a 10uF cap size 0805.

I would recommend to first try to build a single cell verson of this driver and than modify another for two cells. Firmware can be a little tricky for two cell drivers.

Another option I use in most of my single cell lights is this FET+1 driver. It is more efficent in the low modes and you can use the awesome blf-a6 firmware from toykeeper ~toykeeper/flashlight-firmware/trunk : files for revision 250

:smiley:

Somehow I didn’t think to right click his sig or click drag to highlight. Just presumed some blank lines got left in there on accident.

I have some SD103AWS SOD-323 diodes from another project but i’m going to order these you mentioned .
Just ordered also all the other components including pcb …

Two scenarios, both hilarious:

If borked has that signature on accident, how the heck did that happen?

If it's on purpose, why? :bigsmile:

Correct. It is for maximum output that is only limited by battery selection and quality of components. If you do not have at least one light with one of these you should try it. The biggest drawback is as the cell fades so does the output whereas the 7135 drivers did not do that until they fell below voltage. Both drivers have their place but for sheer max lumens the new DD drivers cannot be beat

Well, this is good timing. I took a little time off to pursue other things, and not only is there a plethora of new hardware and firmware out there (the 1K limit has finally been breached!), but Wight is back. Welcome back, and THANK YOU for putting us down a fresh path in driver land.

All is right with the world.

PS Ordering Attiny 25s and 85s and can’t wait to see what I can cram in them.

I have another silly question….
Is there any ready-to-flash firmware available in this forum after i build this driver (for attiny13a) ? in about 2 weeks i’ll have all the components needed , so it’s time to search for a good firmware.

For an FET only driver I would start with STAR firmware or one of ToyKeeper's firmwares. You can find them all in ToyKeeper's Repository under JonnyC and ToyKeeper. For ToyKeeper I would start with starry-offtime and with STAR I would start with STAR_off_time. ToyKeeper's BLF A6 is also an excellent firmware, but it is geared towards FET+7135, and while you can convert it to use with FET only I would try some of the others first.

Thanks for your help , as you said i will start using these until i learn to modify them to have the “perfect modes” .