I always prefer to make something from used things to recycle it. I made this solar light bulb by using used stuffs and few electronics components.
To know more about the nocturnal solar lamp and how it can help rural India, read.
Step 1: Parts required
1. Solar Panel ( 2V,40mA or 2V 150mA or 2V,300mA ) 2. 0.5W Straw Hat White LED 3. Rechargeable AA / AAA battery 4. IC QX5252F 5. 33uH Inductor 6. Switch 8. AA / AAA Battery Holder 9. Wires 10. Prototype Board 11. Plastic Container 12. Aluminum Hanger TOOLS REQQUIRED: 1. Soldering Iron 2. Hot Glue Gun 3. Pliers 4. Wire Stripper and cutter
Step 2: Working
The heart of this light bulb is a very small 4 leg IC QX5252F. It works very similar to "Joule Thief” circuit.
Step 3: Working...
But the advantage of using this chip is that, it does not require a bulky and heavy toroid. It do the same job using only a simple inductor, single AA / AAA battery and a LED.
Step 4: Connection:
Pin-1 -> Solar panel positive terminal Pin-2 -> Battery positive terminal and one leg of Inductor Pin-3 -> all ground (Solar panel, Battery and LED negative terminal) Pin-4 -> other leg of Inductor
Step 5: Solder
In order to make the finished circuit, I soldered the components onto a perforated board. Refer the above schematic during the soldering.
Step 6: PCB
I have made this PCB for making the process easier. Anyone with little experience with soldering can make the circuit.
Step 7: Prepare the Enclosure:
1. Drill holes for Hanger : Drill two holes diametrically opposite, near the top portion of the container. It will used for mounting the hanger.
Step 8: Make the hanger
First cut the hanger with the pliers back blades at the both ends. Now use the hanging part and keep the straight part for future use.
Step 9: Make the hanger...
Trim at the both end according to the height of hanger you prefer. In my case it was nearly 12mm. Bend at the both ends by using a nose plier. Then insert the end in to the container holes made earlier.
Step 10: Make the multi-purpose stand
Use the hanger again for this.
Step 11: Make the terminals for Solar Panel
The solar pane has pre marked terminals polarity. One is positive (+) and other is negative (-).
Step 12: Terminals
Solder a red and a black wire to the positive and negative terminals of the solar panel respectively.
Step 13: Mount the Solar Panel
Drill a 3mm hole at the center of the lid. Pass the wires from solar panel through the underside of the lid.
Step 14: Mounting
Apply glue on the lid and press the solar panel to sit firmly.(You can cover the hole also, it ensures more air tight)
Step 15: Mount the Battery Holder
Apply hot glue on the back side of the Battery holder. Place it on the underside of the lid and press it until the glue dry out.
Step 16: Connect the switch
Trim the battery holder's red wire in two parts. Solder the trimmed pieces to the center terminal of the switch and the red wire still connected to the battery holder to the switch's outer terminal. Cover the joints with insulating tap to avoid short circuit.
Step 17: Connect the Solar Panel and Battery to the Main Circuit Board
Solder the wires from the solar panel and battery to the circuit board. Red wire is for positive and Black wire is used for GND connection.
Step 18: Mount The Circuit Board
Apply hot glue at the center of the lid's underside. Press the circuit board to fix it perfectly. Then place the switch to the side of the circuit board and apply glue to the surrounding. Use a generous amount of glue, but be mindful of not getting any on the lid's inner edge, or it will no longer fit on the container. Then finish the extra wire by using duct tape.
Step 19: Insert The Battery
Insert The Battery into the holder
Step 20: Ready to use
To test the lamp slides the switch to ON position and switch off your room light. Close the lid of the container and you're done. To charge the light keeps the light on bright sun light. Tilt the light lid towards the sun for fast charging. Hope my solar light bulb will give light to many rural people around the globe.