You can find cheap head lamps for under $2 a piece! (source: wikipedia
Sometimes, some things are so cheap, that making it yourself is times more expensive. Same applies to the outdoor head lamps, that have become very popular in outdoor night activities. A search on an auction site will return tens of different head lamps (from a well known origin), for under $2 (batteries not included :D ). Yet, the spirit of DIY usually does not take into account such parameters... After all, DIY is the mother of ideas!
Enough with the philosophy. The project that i will present to you, is a DIY head lamp for outdoor activities, made of simple materials. My version carries 3 high brightness (15000 mcd) 3mm LEDs, powered from 2 LR44 coin batteries. You can get some ideas from my construction, and you can make your own head lamp.
That is all more or less...
Now that i think of it again, maybe it is cheaper than $2...
An acrylic-glass strip, 8mm thick, 2 batteries and a couple of LEDs...
First, i made a pocket for the batter close to the end of the strip with the dremel
Then, i drilled 3 holes for the 3 LEDs. I used a 3mm drill bit, and drilled the glass through-all
With a bigger bit (4.4), i drilled on the same holes, but NOT through all! About 6mm depth, not more!
The 2 holes make a perfect 3mm LED base. The LED fits in the hole
Only the "ball" of the LED lens comes out of the glass surface
The, using the4 dremel, i made the other battery pocket
I cut-to-size the strip. One side is slightly longer than the other
And then i began wiring the LEDs. This is the first LED.
The LED is connected to the positive pole of the battery. LEDs have polarity. The LONG lead goes to positive!!!
And then i put the other 2 LEDs. All LEDs are connected in parallel. This means that all LEDs have their LONG leads connected together to the positive pole
Finally, the cathodes of the LEDs (SHORT leads) are all connected together to the negative pole of the other battery.
Notice that the most left lead (CATHODES) is connected to the left battery on the front side (negative), while the most right lead (ANODES) is connected to the right battery on the bottom side. Pay attention how you connect the LEDs. In case that you are not familiar with the LEDs, i suggest you read the LED theory page, in which i explain how to determine the anodes and cathodes of LEDs. In short, the long lead is the anode while the short lead is the cathode.
I then had to solder the LED leads together, but i had to remove them first from the glass...
To remove them without losing their positions, i used a small piece of duct tape
This way, i managed to hold them in position...
... and i soldered them with ease.
Believe it or not, the first time that i began thinking of the switch was immediately after soldering the LEDs together... I had no plan really for the switch, so i made some switch models. Most of them failed impressively. And then...
I took 2 of the connection extension of the female banana connectors.
I put the first one like this.
Then i drilled a small hole bellow this connector
I took a wire and a small screw
With the round pliers i made the wire round to the same diameter of the screw
And i tinned it with the soldering iron
I screwed the other connector extension in the hole that i had previously drilled. I used the wire as a washer
Then i cut the wire to size and i tinned the other end of it in an water-drop shape
Some things that needs to be done, and some that had to be done already...
The LEDs are fixed in position using a strong duct tape
I removed the bended connector extension to put some glue underneath...
Better late than never
Finishing the housing
Little before the end, i finished the housing of my DIY head lamp:
I cut another thinner (4mm) acrylic glass with the same size, and i made a pocket for the screw of the switch with the dremel
I covered the back side of my headlight with this piece. Then i took an elastic band that fits on my head :D
I used 2 tie-wraps to keep all these pieces together
And here it is... My DIY head lamp
Why i made this project?
Well, actually it all began during some tests that i was running with LEDs and acrylic glasses. I plan to make a neat LED fluorescent-style lamp. During these tests, i had this idea to sink batteries in the acrylic glass.
i like very much all your projects and i try to follow your channel. a question, not specific to this circuit but general. %u0397%u03BFw do you solder or which is the best way to solder a wire to the pole of any battery when you don't own a weld machine?
Dear it is a very interesting and use ful project.But now every one is talking about the alternate energy if you can tell the viewers about some lamp and fan which work with solar and magnetic system it would be very interesting and useful.