2S driver based on Attiny13A?

[Sirius9]

Hi guys and girls,

I am trying to find 2S driver that is based on Attiny13A so I could easelly load UI’s I like to use.
It can be with AMC regulators like good old Nanjg 105c (because I can easelly remove or
stack those regulators to get desired current) or with FET.
Output current I am looking for would be from 2A to about 5A (5.5A) That’s why I prefer AMCs
because same driver can be used for XPE all the way to SST40.

For use with ~3,2V leds like XPE2, XPG2/3, XML2, XPL, SST, Osram white flat, Osram Projection leds etc.
Up to 22mm of diameter (2 board design is OK as well).

Thanks in advance.

P.S. I am also open to recommendations for any 2S driver with this specifications:

- only one mode = 100%

- low battery warning

- low battery cut off

- about 4.5A - 5A output

- for XML2, XPL, SST, Osram white flat leds

• up to 22mm diameter

I would prefer not to get it from US because I am on the other side of the globe and shipping is :confounded:

[Marc_E]

I’n not a driver expert but i know the ATtiny 13A has a max working voltage of 5.5V, well under what 2 Li-ion batteries in series produce, which i suspect is why you can’t find a driver.

[Lightbringer]

Going from 2S (up to 8.4V), down to LED voltage, you’ll definitely need a buck driver, not 7135-based, else you’d fry the latter.

7135s soak up the excess voltage between cell and LED, a fraction of a volt.

[MRsDNF]

Theres probably a few threads showing how to mod the 7135 driver to run 2 batteries in series.

Heres one.

Modding Qlite 7135 to Drive MT-G2?

Hi, I am hoping this can turn in to a sort of ‘How To’ type thread for people who go looking because I had a bit of a search and found a few threads around with some info in them but a dedicated thread on how this is done would be helpful. So this is something that I want to have a go at. Stacking the 7135 chips is fine, I have done that before, but I want to check what is done before that and what exactly this mod allows me to do? I.e. Run two 18650s or 18350s? Only power an MT-G2? etc. I fo…

Edit. Heres a search of the forum for Zener mod.

http://budgetlightforum.com/search?q_as=zener%20mod

[Cereal_killer]

@MRsDNF

Theres probably a few threads showing how to mod the 7135 driver to run 2 batteries in series.

Heres one.

Modding Qlite 7135 to Drive MT-G2?

Yes but OP is asking specifically about running 3v led’s thus he’s looking for a buck driver controlled by t13.

A LONG time ago wight made up an SOIC8 adapter to replace the PIC on an LD29 with an attiny13a, not sure whatever came from that or if it worked for anyone other than him but as far as I know that’s the only option…

[Sirius9]

@Marc E

I’n not a driver expert but i know the ATtiny 13A has a max working voltage of 5.5V, well under what 2 Li-ion batteries in series produce, which i suspect is why you can’t find a driver.

I am not a driver expert either (proven by Lightbringer, post #3) but I have driver from Nitecore MT40 in front of me and it uses PIC12F683 mcu, datasheet says its operating voltage range is 2.0V - 5.5V so, its possible.
Also, the way that ATtiny13A is measuring voltage (needed for battery low voltage detection) is specific to 1S use (doesnt work well with 2S) but all that can be solved with some additional components.

@MRsDNF,
Cereal_killer is right here, I do have zener moded driver that I use for leds like MTG2 but I need solution for XML2, XPL, SST40, white flat…

@Cereal_killer
I think I read about that project of replacing PIC Attiny13a, I am probably still subscribed to that thread! will have to check, thanks for reminder.

Ok, I see now that 7135 is not viable solution but I can’t believe that there are no decent buck 1 mode drivers with battery warning!
I will tri to contact Sofirn (after national holiday) and check how many thousands I have to order for them to consider designing this thing.

[MRsDNF]

[Lexel]

only option is to use a Buck driver

convert the voltage not burn it
LDO for MCU 5V supply

[The_Fat_Controller]

You’re not going to find much in this category, I literally spent days searching for good buck drivers for 3v emitters, I’ve had fantastic results with the White flat LED’s Djozz put me onto using the P4000

6-Mode:

Moon (5mA) > Lo (200mA) > Med (1500mA) > Hi (4000mA)

Double Pressed: Turbo (5000mA)

Triple Pressed: Strobe

Low Voltage Warning:

When voltage is below 3V, it will keep flashing.

When voltage is below 2.7V, LED will shutdown automatically.

P4000

there is also a smaller version (don’t think these have low V warning)
2.4A
2.2A
MT also do a nice one but out of stock till November

Buck is the only efficient way to get from 2S to 3v. until we see a MPPT driver which would be slightly better.

Hope this helps

[Lightbringer]

I used this

https://www.aliexpress.com/item/32746300708.html

in my F13 as a 1-mode driver, which claims to be able to handle up to 15V.

22mm, though, so you’d have to find something similar in the size you need.

Dunno what µC is in it, either.

[YuvalS]

Why do you need 2s pack for 3V MCU and 3.2V LEDs?
Maybe it will be easier to use 2p?

[Sirius9]

@Lightbringer Thanks, I will check that driver and your thread tomorrow, soon midnight here, my brain is struggling

@YuvalS

Why do you need 2s pack for 3V MCU and 3.2V LEDs?
Maybe it will be easier to use 2p?

Because I need it for flashlights, with a long tube for 2 batteries in series, its not a battery pack, and I wanted attiny because I can programm it with custom UIs created by BLF members.

[YuvalS]

In that case, if you don't really need more than 3Ah, you can only use 1*18650 plus a dummy cell (simple conductive rode wrapped in duct tape) so you get 4.2 battery, 3.2v LED and you can use any 3v driver.
the downside is that you use only 1 cell in a 2 cell host :(

[Sirius9]

Yes, that’s also doable, downside is that you get half the runtime and if by mistake you put 2 real cells instead of one dummy cell its game over.

[YuvalS]

@Sirius9

if by mistake you put 2 real cells instead of one dummy cell its game over.

If the dummy is the inner one and you make it hard to take it out you reduce the risk. I am also believe that it is not too hard to use some high voltage protection circuit

[Lexel]

@YuvalS

@Sirius9

if by mistake you put 2 real cells instead of one dummy cell its game over.

If the dummy is the inner one and you make it hard to take it out you reduce the risk. I am also believe that it is not too hard to use some high voltage protection circuit

4.7V zener diode plus auto reset fuse