C8 driver

Hello,

i would like to ask if the bypassing driver in C8 style flashlight is safe?

I was trying to find a simple way to demode or to mode a stock 5-mode driver to single (ON / OFF on high) and that question came to my mind.
Only problem, as I see it, is a lack of low voltage protection which is eliminated with the use of PCB protected batteries.

ty
Vejs

I had a C8 mule once where the MCPCB was directly connected to a “contact plate” instead of a driver. It was direct drive, effectively.

This works if the battery and overall resistance is in line with heatsinking of the LED and the respective forward voltage.
However, the more convenient way of achieving this would be a 1-mode option in a DD driver setup.

ps: Welcome to BLF!

If the driver uses 7135 regulators you could solder wires from battery+ to the enable pin on each 7135. That would bypass all firmware functionality but keep current regulation. That would be safe, providing that you can judge for yourself when your cell is nearing depletion. Simple though? Well, only you can decide for yourself, I think it is.

However, if the light isn’t actually a Convoy original, chances are that the driver isn’t based on 7135s.

Welcome to BLF by the way!

Normally I’d just say “get a Biscotti driver and set it to group 12 (always on)”, but I understand the itch to mod :wink:

Oh, and yes, welcome to BLF! :partying_face: I can see you already speak our language, you’ll fit in just fine in our nut house :stuck_out_tongue:

Guys, thanks for the welcome

@USA it is a more convenient way, but this was a fast fix because you cant play airsoft with 5 mode and whitout memory option: D

@Mike C I think i can judge if its near deplition but i thought that PCB protection on battery would prevent this. And now, as I’m reading about battery protection, i see that i’m wrong and that’s just to prevent one battery from discharge more than other in serial connection. Please, correct me if i’m still wrong.

Btw, it’s Ultrafire and driver is CX-5117C-03 (i suppose that is not good for sugested solution)

@Jack Kellar I’v got itch: D you’re right about that, but on term on BLF language i’d say that im a far away from the native speaker, but i’m learning

Direct wiring with a good cell and a crappy stock LED on a crappy stock aluminum MCPCB could be trouble. I've de-soldered LED's this way in the past, and/or melted springs.

However done right with a LED that can take it, on a DTP MCPCB, and bypassed springs - then you got something that's bright and works, hot I'm sure. Then the LVP is you - notice it's getting dimmer, time to re-charge.

I actually built/modded a few single cell lights by taking crap/dead driver boards, removing the electronics, and drilling a hole down the center of the board so I can run a wire directly to the LED. What I was thinking of doing was adding a 1/8” mono audio jack somewhere by the switch, and making a special 1/8” mono to JST cable, then I could just plug in a cheap LiPo LVM to check the battery - or even charge it with an RC balanced battery charger.

They are supposed to have low discharge cut off… I guess… I’ve never had one do it though. Maybe my protection circuit was bad or I don’t know how they are supposed to work. I also don’t know what happens once it trips. Just have to slap it in the charger and it’s good to go? I only have a very small amount of protected cells, I only use them in my headlamps. Now days all my headlamps have low voltage monitoring.

If it has a NANJG driver, you can pretty much just solder-bridge one pair of contacts on the spring side, no need to even remove it. (Bridge the 7135s’ enables to the µC +V.)

For some truly craptastic “Ultrafire” AT-01s, I just unsoldered the LED wire from the built-in FET (?) to the negative end, so it was pretty much direct-drive except for some parallelled chip-resistors. Always-on, no modes, no LVP (if it even had it), so no annoyance switching modes from a flickery switch.

Anyway, depending on what kind of driver’s in it, there are always ways to do that.

And on my Cometa, when I was annoyed how dim it seemed, I did a battcheck and saw it was only 3.2V or so, just about ready to nosedive and croke. So if you get used to how bright it should be, you should also be able to tell when it’s running down.