Cheap Flashlight Teardown

Chances are, if you've searched for an led flashlight online then you have run across one of these cheap lights.

These lights are very cheap, take a single AA battery, but surprisingly they work very well. I have many of these around my house for when the power goes out. They are small, focusable, great battery life, and put off a good amount of light. For the price, I have nothing bad to say about these lights and I recommend buying them.


But here's a simple teardown of one.


First off, here's the light in all it's glory. Measuring 94mm at it's length and 26mm at its thickest point.

The button at the back is a simple on/off click button. The light itself has 3 different modes. A high, low, and flashing setting. Clicking the light on and off or pushing the button part way allows you to switch between modes.

You can unscrew a ring on the front and remove an O-ring and lens.

You can see in the above photo there are two opposing notches in the silver part of the reflector towards the outside. But using my caliper I was I able to insert the caliper edges in to those slots and unscrew the unit from its housing on the main body.

I wasn't too sure where to go from here and thought maybe the led unit was all glued together. But then I kept messing around with it and was able to remove that plastic ring and reflector bit. This then exposed the led module. The led is a Cree XR-E or XR-C (probably the lower model XR-C) from what I could look up. There's not any specific model identifying information but it does look like one of those two models. Cree makes a good led so this is nice. From my testing, this led seems to be the best at 3 volts and 400 ma current draw.

Now when I removed the led, I noticed some circuitry behind it. This wasn't what I was expecting to see there. I figured the led was going to be the only thing at the front and the circuitry was going to be in that clicky switch in the back. Nope, all the circuitry and driver was right behind the led.

And that's that. Overall these are great little lights for the price.

Thermoelectric coolers are so cheap these days

I remember when buying a thermoelectric cooler, I'd have to spend $25 for one. I just ordered 5 on ebay for $12. It's great to see prices go down for components. Anyways, I plan to use one or two with some heatsinks to make an active phone cooling stand. I just need to find a way to get good contact with the phone.

Here's a heated small heatsink I had and placed on the cooler, then it gets switched on.

Phone Cooling

I was messing around with using a cell phone as a security camera. The phone has wifi, a battery, can be easily plugged in to keep charge. and there are apps out there that can turn them in to these easy webcams. So I decided to play with it.

While it all works good and well, something I noticed was the phone got hot. Like, really hot. I decided to shut off the app before things got out of hand but I did snap some thermal pictures before that. The app streams 1080p video at the highest frame rate it can, so it taxes both the wifi module and the processor.

At first i found it interesting that all the heat was concentrated in such a small area. But then I realized that's normal since the battery takes up most of the internal body. You can feintly see the battery outline as it started to heat up as well.

So, this has made me decide I think i want to make some sort of cooler stand for phones. Like a heatsinked phone stand. This leads to a few options, some overkill, that I may explore.

• Just use a fan blowing on it - This has it's pros for a few reasons. It's low power, doesn't need flush contact with the device, no maintenance or real worry about it failing. Downside is air cooling won't be the most effective option.
• Heatsink plus Fan - This is almost as simple as just a fan. Heatsinks are cheap (I have many lying around) and they work well. Good enough for a cpu in the desktop is probably good enough for your phone. Downside to this, and the rest of the options is that they need a flush and direct contact with the device.
• Water cooling - This adds a lot of uneeded complexity to the situation. You need tubing, a pump, a radiator, and still a fan to get this working. The benefit over just a heatsink may be mnimal as well. So as I write this, it's already out the window.

I may think of other options but this is now an official project for me to think about. Though I still have other projects I haven't finished. Need to get some stuff done eventually.

Yeah bought some screws

That's right I'm now the owner or a brand new M3 screw and nut set. I bought 100 pieces of 10mm and 16mm screws with nuts. These are great little screws and frequently used in 3D printing for fastening. So now I have a few more options for printing and fastening things.

My Car Has Eyebrows Now

I have a 2006 Nissan Altima and it's a pretty boring car. I noticed that newer cars these days all have the led running lights. And you know what, i think they look awesome.

So my first instinct was that it's time to get to eBay and find some of these for my car. Unfortunately that didn't happen since pretty much the only headlight options for a 2006 Nissan Altima are the stock lights or some overpriced projectors. I had recently used a headlight restoration kit (which worked very well) so I didn't really need to replace my lights.

Here comes the ghetto part. I got on Amazon and ordered some 12 volt LED strip lights that were waterproof. Strip lights are very cool because you can cut them to length and they take a decent voltage range out of the box (resistors already on ths strip).

So I bought the "pure white" led lights but when they came in, to my dismay they were a tinge of blue. I got lazy and decided to just go with it. I regret that decision but if I want to redo it in the future it will be easy.


The first task was mounting. I wanted them along the edge of the headlight but not to be easily visible. The options were to open the light and glue it in and reseal the light (seemed like a lot of work), glue to the outside (would look tacky), or the final option I went with which was mount on top of the light but under the hood.



Mounting here proved easy and still let enough light out to be noticeable. These aren't super LED's in the strip for $6, so daytime they are pretty dim. But they work. So I cut strips and glued in place with a waterproof silicon glue.

Next was figuring out how to turn them on and off. Now, my headlights have an on off feature for when it gets too dark. I could tie the LED's in to that but then they would only be on at night with the headlights. I wanted them on as long as the car remained on. Another option was to add a switch in place for them and wire it to the battery. But in that case, I would have to remember to turn them on and off every time I drove. So that was out. When you're dealing with a battery, you have a constant supply of power, so I had to find a smart way for the car to turn the lights on an off for me.

So I was thinking about creating crazy switches and circuits to detect of the car was running but I ended up finding an incredibly easy way to accomplish this. If you turn your car and and think what electrical systems go on/off when the car is running you can quickly guess the radio. Having hooked up many stereos in the past, it finally clicked what I could do.

The stereo in a car is considered an accessory. And most people will notice that their key positions has an accessory position on it that gets turned on when the car turns on. So by tapping in to that accessory power line, I can turn anything on and off based n if the car is on or off.

Yeah, zipties

So I bought a 12 volt car relay and a fuse block (always use fuses, especially when you are rigging up something) and installed it to the led strips and hooked it to the battery. I then ran the coil power to it from the Power line running to the car stereo. This means I could power the LED strips and in the future fog lights, with using very little power from the stereos circuit.




Once it's all wired up, I now have my own ghetto LED light-blueish running lights.

I had a lot of led strip left over so I ditched the old yellow bulb courtesy lights and glued the strips in place under the doors. Used wire taps foe the factory courtesy lights to run these so everything just worked.

WD-40 Turbo Air Blower Teardown

Using canned air to clean electronics is pretty useful. That is until it runs out. That's where the WD-40 Turbo Air Blower comes in. Or where it should come in I should say. It lacked in performance ever since I got it on Woot many moon ago. For some reason I've held on to it, but I finally decided it's time to tear it apart. Let's do this.


Here it is in all its glory. Standing about 12 inches tall, it's self contained in a nice aluminum body with a single switch on the side and a charging port on the bottom. And, uh, ignore the sticker.

So where do we start, well the only visible screws are in the air intake area which is touch to access. I got to them and unscrewed them but that didn't seem to do anything. Looking closely it looks like it was just to mount the motor to the inner plastic housing.

So how to get the plastic housing removed from the aluminum? Well a little tinder prying and the top came off. After much prodding and prying though, I still was unable to get the inner housing out. So I flipped it over and with some more tender bench vice grips and hacksawing I was able to get the bottom out.

 Immediately removing the bottom and you see the battery pack which is just a 4 cell NimH pack. 

Interestingly, the power wire ran through the middle of the 4 pack of batteries with an open spot in the wires middle to connect them to the battery terminals.

Battery specs.

The cell pack was dead so before tearing it apart too much, I hooked it up to a bench power supply and was able to get a max speed out of about 16 miles per hour. 

So after a lot more tinkering, it appeared the inner plastic housing was pressure fitted inside the aluminum. I trying pushing it out but the aluminum just started bending. Interestingly, it was pretty easy to peel with cutters. So I started peeling.

And peeling and peeling.

Finally the goodies.

I was afraid at first (before removing the housing) that the surface mount switch was taking the entire load of the motor which was a few amps. But they actually did have it set up with a Schottky transistor format. 

The takeaway is that this was just a simple motor with a fan on it. Pretty uninteresting even by my standards. But now I have a nice little motor with a turbine that fits the shaft.