Custom 17mm 5Amp PWM-less linear driver-preliminary

Problem:serious lack of high quality high current user friendly drivers,especially in 17mm size,1xLi-ion

Solution:only possible-design it

From blank piece of paper few months ago to this:


-input voltage 2.8-4.35V

-5 Amperes(default) current

-off-time mode memory

-no components on spring PCB side!

-place for decent size (up to 8mm bottom diameter) spring on spring side pcb

-PWM-less TRUE CONSTANT CURRENT on all modes-no acustical or EMI noise

-significantly longer run-times on lower modes compared to PWM-based(FET or AMCs) drivers-even >2x possible

-stays in regulation on lower modes for longer periods of time compared to PWM-based(FET or AMCs) drivers

-6mohm power mosfet

-pmos reverse polarity protection

-calibrated voltage reference

-less than 100uA parasitic current in sleep mode (40uA typ.)

-enough space for easy led wires soldering(up to 20AWG,22AWG recommended)

-2.6mm total thickness(including 1.6mm PCB),16.9mm diameter

-simple,intuitive UI,no disco modes

-modes: 0.3%-1.5%-20%-100%,standard half press to increase mode

-0.3% disable via solder "moon" 1 (no solder mess on gnd ring anymore)

-"turbo" mode option (140%@4.2V,drops linearly to 110%@2.8V),turbo enable via solder moon 2

-tailcap switch and electronic side switch capable,independently or both at the same time with single firmware!

-three separated e-switch user interface types(rather than one complicated)

-2-step low voltage protection(3V-restricted power; 2.8V-sleep)

-over-temperature protection (threshold change possible by user)-disabled by default

Over-temp. protection set:

A.)Tailcap switch

Turn on the flashlight and wait until temperature rises.10-15 fast half presses sets current flashlight tempererature(driver temp to be more precise) as temp. threshold(some blinks).If flashlight becomes hotter than temp. threshold,driver adjust current to maintain temperature at threshold level.

To disable overtemp. protection:>15 fast half presses(some blinks)


Turn on the flashlight and wait until temperature rises.Holding button switch pressed for 12-15 sec sets current flashlight tempererature(driver temp to be more precise) as temp. threshold(some blinks).If flashlight becomes hotter than temp. threshold,driver adjust current to maintain temperature at threshold level.

To disable overtemp. protection:Holding button switch pressed for 15-20 sec (some blinks)

Note:do not run this driver "in air" because even with activated overtemp. protection,temp. rise may be faster than driver could decrease current fast enough to protect itself.

E-switch user interfaces:

1.)UI_1-"standard" UI

-normal button switch press increases mode: sleep->(mode0)->mode1->mode2->mode3->sleep

-double press decreases mode

-long press from sleep->max mode

2.UI_2- Smooth Ramping UI

-when switch is pressed(flashlight is turned off) driver starts to ramp current up or down from current that was stored as last one(this means driver remembers last current before shut down),release switch to stop ramping

-pressing switch again- driver ramps current in opposite direction

-if switch isn't pressed for more than 1.5sec,driver goes into sleep on switch press

-it takes about 4.5sec from min to max or from max to min

-one blink at 50% current,2x blink when current=max.

-10 bits resolution on lower currents,8-9 bits on higher currents

3.UI_3 "Simple UI"

- double press increases mode

-single press->driver shuts down

-single press from sleep->last used mode

How to set UI:

-turn the flashlight on and hold button switch pressed for 7-12sec(some blinks).UI is changed to next one.Repeat to get UI you want.


E-switch protection:

-if e-switch is pressed for more than 20sec(accidentally in pocket,bag etc.),driver shuts down

Connection diagram:

This driver(older version) Vs 105C:

Approx. estimated price: 12-14$/piece (min. 4pcs order,but with free worldwide shipping)

More additional info later.

Sounds fantastic.

Will you send one to HJK for testing and review?

Will you be offering these for members in full ready to go form or in kit form?

What kind of price if you do?

Thank you

Edit: Can changes be made for it to do 9 amps or more?

Are you looking at a driver specifically for the MT-G2 any time soon?

Edit II: lol

Can these run master slave?


Interested for sure

Can’t be cheap…and sure isn’t gonna be DIY

Very nice. I am interested if you do offer these for sale.

Don’t tease me bro.

Very interesting driver, both very high current capable and current controlled low modes, that is fantastic. Looking forward to the final driver :-) !

Very cool idea and quite a low profile compared to the105c.It's an impressive concept and +2 on sending one to HKJ for testing.I would assume mode programming is done through the side switch?I like the 140% for turbo and I'm wondering if the turbo steps down at all or can it go till voltage is too low.Sorry for the questions,not really familiar with a fet driver.

Great work!

Will def be interested in a couple of these babies! :slight_smile:

Wow!!! Looks awesome!!!

Would sound great even @ 20mm.

definitely interested in owning several of these if it ever goes on sale :smiley:

I sure hope these will be available for purchase some day, this is amazing. Great job.

Here’s my money… please take it from me for several drivers! :bigsmile:

OK, I am interested :slight_smile: but, it would really be nice to have –8.4V input

I would be really happy to have a 2-cell version of this driver.

Sounds great. Hoping you branch out to a 2S version.

Very nice! I am looking forward to this driver.

You should sell this driver through Mountain Electronics. I’ll buy several.

I want one! How much? PayPal ready! :heart_eyes:

Very cool.