How to turn driver into contact board?

Flashlight Modding and DIY Parts
1

This will probably be a very simple question.
This is the driver from my Supfire L5. I want to use it as a contact board and retain the original switch. After I strip off all of the other parts, where is the best place to wire it up to my replacement driver? I assume I will need 1 ground wire, 1 power wire, and one wire for the switch.

2

Outer ring is ground, just use the + LED pad as the battery + (or input) [the 7 vias in the center are the battery + connection point], and wire one side of the switch to the pin (or sw pad) for momentary operation

3

So the LED+ pad will still have continuity after I remove that resistor bank?

4

Might want to bridge across the pads once you remove the resistors, or use the pads before …good call, didn’t realize that the pad was past that resistor bridge… (all the pads closest to those 7 vias are electrically batt +)

5

Hmm maybe it would be easiest to just scrape a little right on top of the vias?
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There really isn’t much exposed metal on the switch pins to solder to, do any of the other pads connect to switch+? It looks like to me that the right side of the switch connects to ground, but I’m not totally sure.

6

I figured you were writing up a tutorial here when I saw the thread title. :frowning:

I’d do these:

  • use the pads where R2 through R4 were for BAT+
  • scrape where Q2 is marked and use that for GND (I assume there’s a driver ledge, this keeps your wiring away from the ledge)
  • I can’t really see clearly for the switch wiring… whatever contact on the switch isn’t GND but shorts to GND when you press the switch. Check with your DMM.
7

I corrected my topic punctuation for you wight.
I should be able to get it now. I figure that switch probably connects directly to the mcu (I think the top right pin?), so I can use that pad since it can be a small guage wire. It’ll be easier to see once I get the components off.

8

Thanks, heh!

I can’t see for sure, but I kind of suspect that that top right pin is V+ for the MCU. That pin also appears to be decoupled w/ that cap that’s right above the MCU - this supports the conclusion that it’s V+/Vdd, plus that’s a normal PIC pinout: https://www.google.com/search?q=pic12f683&es_sm=93&tbm=isch

It’s hard for me to see, but I think maybe it’s actually the pin immediately to the left of that pin. (Upper right is Pin1, so that would be Pin2.) There appears to be a trace which shoots under the middle of the capacitor there.

I think you’re right, once you get the components stripped it will be easier. Do you own a DMM?

9

Actually, and I’m guessing now, but I think one of those SOT-23 components below the switch is a P-FET for reverse polarity protection and the other is a low-voltage detector used to establish rudimentary LVP.

10

Yes I have a meter. I’ll poke around at it after work tomorrow to see what I can find.