People in rural areas have been using sooty kerosene lamps to dimly light their homes, children are suffering from lack of adequate lighting and they rely on dim, smoky, and dangerous kerosene-based lighting for their evening studies. In the initial days, I made this Solar Lamp for providing a low-cost solution by replacing their harmful kerosene lamps.

STEAM EDUCATION

I designed a kit for the Solar lamp for initiative in STEAM Education for KIDs. It will be a great start for them to learn Electronics and aware about use of renewable energy.

Features :

1. One day charging can give light up to 20-22 lumens (about three times the brightness of a kerosene lamp) for the entire night.

2. A 800 mAh AA battery can be charged fully in single day bright sunlight.

3. Uses high-quality AA NiMH battery which can work long period.

4. Uses a high-quality solar panel ( 2V / 160mA ) to charge the battery.

5. Automatically switches off in bright light to save charge and switch on in dark.

6. Battery over discharge protection circuit.

Advantages :

1. Improves literacy: Solar light bulb improves literacy because people can read after dark more easily than they can by a candle or kerosene lamp. 

2.Saves Energy: As the light is bulb is charged through solar energy (free energy) it saves energy.

3. Reduces air pollution: Use of solar light bulb decreases the amount of local air pollution. With a decrease in the amount of kerosene used for lighting, there is a corresponding reduction in the amount of pollution produced.

4. Reduces greenhouse gases: Solar light bulb gives light with no carbon dioxide (CO2) emissions.

PARTS :

1. Solar Panel ( 2V/160mA)

2. Straw Hat White LED ( 8mm )

3. Rechargeable AA/AAA battery ( 800mAh)

4. IC QX5252F

5. 33uH Inductor

6. Slide Switch

8. AA / AAA Battery Holder

9.PCB

10. Plastic Container

11.Aluminum Hanger

Assembly Guide

Full guide is available on Instructables

Working

The heart of Solar Lamp is a very small 4 legged IC QX5252F. It works very similar to "Joule Thief " circuit.

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.

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