Super Bright LED’s in old flashlight.
I was cleaning up my workshop recently and came across a nifty little tool my dad had given me when I first moved out of the house. A bit driver with a flashlight built in. It had a lot of cool features, such as a revolving butt cap to make turning in your palm easier, an extending magnetic pickup in the bit end, bit storage, and lastly a light in the handle to illuminate the object being worked on. Going completely A.D.D., I scooped it up and tried to turn it on. Dead. Or broken. Which? I had to find out…
I figured I’d throw in some batteries, and if no luck poke at it with my multimeter then toss it back in the tool drawer. But I wouldn’t be worth a hoot as a tinkerer if I left well enough alone, now would I? Let’s take a look at our victim,, er, project.
WARNING! All images were taken with my cell phone! May contain harmful amounts of bad pictures! (Hey, it’s a kitchen table hack.)
Sturdy little bit driver.
It has a sturdy plastic/rubberized handle with spinny-end-cap thing, takes standard bits and has a flashlight built in.
Extendy! This is about 1/3 as far as it will extend.
Yes, extendy is a word…
The bit holder thingy under the end cap. This also holds the battery pack/flashlight in place.
Flashlight module.
The flashlight module has a belt clip built in, which brings me to believe it was meant to be taken out and used as a standalone flashlight if needed. It’s a little bit of a pain in the butt to get it out, so I don’t see where this would be very convenient. You have to push the power button down while sliding backwards (like extendable legs on steel tables) after you remove the end cap and take out the bit holder. I think I would just rather hold the screwdriver with the light on, but good job tacking on one more feature Mr. Design Engineer.
That’s the basics of the light itself as far as form and function are concerned. Now on to the, uh, fix? Yeah, we’ll call it that.
One incandescent bulb. Check.
The bulb was adequate, but could be much better. And there could be more of them.
Fresh Batteries…
Check.
Test for function…
Check.
Now it should be noted that in this shot the flash was turned off. My phone had dropped to <10% battery and would not let me turn off the flash. So that ‘really bright’ lookin’ bulb there ain’t really. A point of reference; the blue reflection on the table is the Harbor Freight work light that is hanging from the cabinet providing me extra light to work/shoot photos.
These are really bright, and they give them away free! Check your coupons! (No, they are not paying me. Can you say 27 high intensity LED’s, a DPTT switch and a battery box for free?)
But, anyways, the light/bulb all work. It was a smidge corroded, but a pencil eraser took care of most of that. So, it works, I put it back together, left well-enough alone and just put it away. Thanks for coming!
…
Riiiight. It’s time to MODIFY!
Case all opened up.
The bulb had to go… to the spare parts bin.
He’s pointing to something… What is it boy? Whatcha got?!
In this wonderfully clear cell phone pic I am attempting to point out the ridges where the bulb was held in. These will become the space for the springy contacts for the + side of the AA battery. This where also be where I tap into the + power.
The front lens assembly.
The front lens assembly is made of a clear plastic. Definitely not acrylic.
Board from another free high intensity light.
This will be the platform that will be modified for the new lighting. As much as I was tempted, I decided to leave the laser pointer out of it. {sadface}
Drill hols about 1/16″ wider than the LED’s.
The clear plastic was fairly easy to drill. As evident in the other pictures, there were already slots in the inside of the plastic. I just drilled into the corners to prevent undue twisting and everything turned out fine. I made sure to run the drill at high speed for a second or two in the hole to make sure it was cleaned out well.
Easier than I thought it would be.
Used a razor blade to clean up the excess.
Nice, snug fit. Very happy.
Amazingly, everything lined up perfectly. I was quite surprised!
Negative side of board marked.
I marked the circuit board with which side is negative. Once this is all hacked up I’ll have to look at the LED’s to tell. And embarrassingly, I can never remember which is the cathode. Kinda like, after a networking project I’m all, “Orange white, orange, green white…” like a champ, but 3 months later I need to make a cable and go full alzheimers on the ‘B’ standard.
Diameter measured.
With the board/LED’s pushed into the clear plastic, I took a sharpie and marked where to cut the board.
Cut along the mark,
Now here is the part where I had to deviate from the whole, “Kitchen Table Hack”. I walked out to my shop to use a pair of tin snips and a metal file to get this to shape. A couple reasons; tin snips work great for cutting PCB’s, I don’t keep those or a large file in the house, and the mess at the kitchen table would have driven my wife over the edge. We will NOT be telling her I burned the table with my soldering iron… again.
LED fell out! Oh noes!
Apparently the solder holding these LED’s was a little brittle. When I cut close with the snips, it cracked and the LED on one side came out.
Easy Fix.
It was easily re-soldered. The other side was touched up too.
Snazzy.
Ince it was all sturdy again, it was slid into the lens? assembly. Looks great so far.
Test fit looks good.
Slid in with no problems. How’s it look from the inside?
Everything clears.
Now my 7-year old daughter, God love her, pointed out to me something I had not considered. “Daddy, is that going to take up too much space when you put it back together?” (Yes, Kitchen Table Hacks involve having kids leaning over your shoulder. But it’s a great way for them to gain interest in science and electronics in general).
Thickness is the same.
She’s was right, of course. This would add a good 2-3mm of thickness to the overall size. But, looks like the lens was almost exactly the same thickness.
Lens popped off.
So off it came. This should mean the final product should fit nice and snug.
Drill the positive, er negative , uh, copper thingy.
Next I drilled out the copper lead on the switch. I have tried, in the past, soldering to leads like this with mad amounts of failure involved. Sometimes it’s just crappy metal, and no amount of sanding and degreasing will make solder stick to it. I’ve ended up melting switch housings before I got copper to tin up on these things.
Little large, but the smallest I had.
So the hole is basically there so that if solder will not stick to the tab, I can at least pass the wire through, twist it up and glob enough solder on it to hold it in a more mechanical sense. Yeah, elegant I know.
Some wires and a button.
In my parts bin (the top of my desk) I found some nice little wire with a switch on the end.
Hey, that looks useful.
I did particularly take notice of the male pins soldered to the wires. If the pitch is correct, I can just tin these up and tack them to the LED posts!
Marking which is which.
Two of the same colored wires means I need to mark one as negative. Giant sharpie to the rescue. If not for this I would totally goof up my polarity. I do anyways.
Tinned up?
I used the light housing and a little electrical tape as a clamp to hold the wire while I tinned* the ends. I say tinned loosely because the solder would not stick well, so I just kinda got a couple globs on there.
Soldered on.
But, it worked fine because the leads tacked right on to the LED contacts.
Bent to fit.
I bent the pins so it would fit into the cavity where the incandescent bulb used to sit.
Lookin good!
So, all soldered up! No, wait. Uh, the… positive… (this is where I have to imagine electricity flowing in and out of batteries. I probably look like private Pyle from Full Metal Jacket).
Nope, now lookin’ good!
I had the wrong wire soldered on. This switched the negative side. So, a quick switch and we’re good to go. (Also, as concerned as I was, this copper tab was a DREAM to solder. It took solder like a duck-faced teen on Facebook takes compliments.)
Crummy window alarm.
More parts. I need something to reinforce and fill the gap at the end of the AA battery on the positive side. I figured a piece/couple pieces of PCB could fit that bill. My original intention was going to drill through the board and solder a wire into it was a large glob of solder on the battery side as a contact. But when I saw this guy, I knew I could do a little more elegant than that.
Battery springy thing!
One side had a PCB with a bit sticking out already with solder on it, and the other side had a springy battery thing.
Board pieces with solder & battery contact.
I took the pieces to the place that is not my kitchen table and trimmed up the board and accidently broke the solder tab off the battery contact. Also note, lower quality circuit board more crumbles as you cut it with the snips. Sanding is definitely needed.
Soldered together.
Once the pieces were sized and cut, I noticed that when placed back-to-back the holes lined up perfectly. So, I heated them up and let then sandwich together.
We have retention!
Once together, I wedged everything in place and plopped a battery in. The boards and contact fit snugly on their own, and the battery slid in and stayed very well.
Stiff wire. Mine!
Once the boards were back-to-back, I needed a way to get positive voltage from the battery to the LED’s. I could have just soldered to the metal contact springy thing, but I wanted everything to be… all together, one unit. So my plan was to heat some wire and pass it through the soldered/sandwiched boards (*snicker), then solder that to the battery contact thing. (What is that thing called? **Edit: According to www.digikey.com they are called battery contacts.**) To get nice stiff wire, I used the really long lead off this resistor. (Don’t worry, I left about 1/8″ so I can throw if back in the parts bin)
Wrapped, twisted and soldered.
Getting the wire hot enough to pass throughthe solder and through the holes was difficult to be nice about it. Eventually I de-soldered the boards, passed the wire through, then soldered/sandwiched the whole thing back together again. Then I wrapped the excess wire around the board and twisted it up on the other side. This kept everything tight so that when I soldered the battery contact to the wire it would remain a rigid unit. (I know, this is so ghetto.)
Negative, er, positive lead soldered on.
The lead was then very easy to solder the positive wire to.
Let there be light!
A test confirmed everything was working well. If you will, however, notice that the positive wire is very close to the negative tab coming off the switch, so I had to bend it up out of the way. That was fine, until I test fit everything and noticed it was now very close to the wonderfully protruding male posts that I soldered onto the LED’s. So the contact positive wire was bent down, the switch tab was bent down and the male posts were bent back up… which broke both posts off the LED’s.
Now I don’t have any pictures of this, likely because I was too busy saying bad words while I was soldering everything back together after flattening it out, to take pictures.
Holy cork, that’s with the flash and the worklight above both on!
But, once together, everything worked like a champ. I mean, that looks white in the picture, and the flash has fired. That’s a clear piece of plastic. I’m quite happy with that.
Diggin it!
Once together, everything is looking good.
Plenty bright. This is with the lights off.
A little weird. The shadow is like a negative laser pointer.
It’s like an eclipse, of your soul!
Again, this is with the flash on the phone turn ON.
So What did I accomplish and learn along the way?
- Old stuff is fun to make into new stuff.
- Trying to hold a tiny board and solder it while your daughter is watching will result in you burning silicon into your thumb. It sticks.
- Tin snips are God’s gift to hacking up PCB’s.
- Table runners hide soldering iron burn marks.
- Kitchen Table Hacks are great ways to pass an evening while still remaining “in the flow” of the household. You get to do what you love while still being ‘out with the family’. It is also a great way to get your kids involved in learning how things work.
Finished, useful and happy. I love feeling productive.
Hey, now that I think about it, the inside diameter of this screwdriver is really close to the diameter of one of those free Harbor Freight Flashlights…
