Trouble with BLF SRK V2 driver

Flashlight Modding and DIY Parts
1

Hi all, new member here…

I’ve recently picked up a couple of BLF SRK V2 drivers from MTN electronics for some projects I’m working on. I’m probably missing something really obvious but I’ve had a quick search around here and can’t find any info on how to solder it up…

I’ve soldered up the switch and LED wires but can’t get it to work. Swapped back to the old original driver and all is well. Is there another jumper I should be bridging or something?

Any help would be greatly appreciated!
Cheers,
Jim

2

Did you get a 1S or 2S version? Have you checked that it is the correct version for your light?

3

IN MY CASE!

Using the 7135 driver, from Mountain:

I found that the factory driver was slightly thicker than the aftermarket, and the battery tube didn’t make good contact with the negative ring on the driver. IIRC, I added some solder beads on the ring to help it make better contact and it has worked find that way. Might have to reinforce it a bit better as the solder would compress down pretty quickly.

4

Speedy replies, thanks…

It’s SRK spec firmware with ext temp sensor. 1S using with a 3xLED SRK style light.

I’d seen some pics of the solder blobs to increase thickness but it’s the same thickness as my stock driver so I don’t think it’s that (1.6mm)

Pic added with original driver for clarity.
Cheers,
Jim

5

I don’t see any solder on the sw+ pad.

6

Ahh you might be onto something here… I assumed the SW+ pad is the one marked with tIN underneath it? Is that incorrect? If so, which one is it?

Cheers,
Jim

7

Should be the Pin 2 pad.

8

That’s got it!

Thanks for your time,
Jim

9

What would happen if the sw+ and - wires were reversed ?

10

It would work.

11

No, it would run in reverse. That’s how DC works.

12

Making a joke? SW = switch = eswitch…

13

Yeah, a switch is just a switch and doesn’t care which side is marked plus or minus.

14

Unless it’s one of those tricky illuminated switches. :wink:

15

If you make it run in reverse it’ll recharge its own batteries. Maybe use a DPDT wired up as a forward-off-reverse?

16

That’s a good point, but you’ll need to establish some back-pressure to get the light going into the LED.

17

Well there are thousands of people on Youtube who say they can run their cars on water, so I guess anything is possible.