A cheap DIY flashlight using LEDs (and other stuff I found lying around in my room)
It's a very simple project and very easy to do.
Duration: Took me 2 hours
What You Will Need:
Step 1: The Circuit
The LEDs (and resistors) are connected in parallel. Refer to the schematics attached.
I used 3 220 Ohm resistors. The resistance of the circuit depends on the voltage of the LEDs. If you are a beginner at circuits, you may wanna check out this instructable, it will help you calculate the right resistance to apply
The LEDs are also connected to a toggle switch which will control the on/off mechanism of the LEDs.
I recommend you use a breadboard to prototype your circuit before soldering it on a perfboard. See attached diagram of the breadboard prototype.
Step 2: Soldering
Next, re-create your circuit onto your perfboard for soldering. Start with the LEDs and resistors. Then solder two connecting wires at the +ve and -ve ends of the circuit. These wires will be connected to toggle switch and the power source (batteries). Remember to refer to the schematics in the previous step.
Step 3: The Tube
Once you're done soldering, get your toilet paper tube and make a small enough hole, for the toggle switch, at the center of the tube.
Then carefully insert the switch and wires in the tube. Make the switch pop out (about halfway) in the hole you made. The connecting wires should go through the tube and come out the other end.
See attached photos.
HOLD THE SWITCH STEADY
Despite how small you made your switch hole, your switch will be loose, especially when you try to turn it on/off. You have to be creative here and find a way to hold it steady. I used some Sugru. I applied it inside and outside the tube, around the switch. If you do not have Sugru, you can try gum or tape.
Step 4: Battery Holder
I did not have a battery holder so I had to make a cheap one. Like a mention earlier, some of the parts I used in this project happened to be lying around in my room. I had to be creative.
If you have a button battery holder than can hold 3 3v button battery, then good for you, skip this step! Otherwise, you need to get creative again. I made my battery holder using some plastic bottle caps, coins, some Sugru and tape. (See photos)
I made a hole in the cap and made the connecting wire go through it. Then applied some Sugru inside the cap, around the wire. I then soldering the wire to a coin and placed the coin in the cap, and used the Sugru to hold it steady. I did this twice (2 caps), for both -ve and +ve wires.
Once completed, I inserted the battery in one cap (taking note of polarity) and closed it off with the other cap, using tape to make it hold.
Step 5: Finish
That's about it. Place the battery holder inside the tube and seal off the tube with some tape.
You can check a demo of my flashlight here.