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In India, one of world’s largest, most populated countries, over 74 million rural households live without power. Children study in harmful smoke,average people spends 5% of their income on lighting fuel,people burns wood for lighting.

A single kerosene wick burns an estimated 80 litres of fuel, producing more than 250 kilograms of carbon dioxide per year. Multiply that across the developing world and kerosene lamps emit 270,000 tons of black carbon annually – equivalent to 240 million metric tons of CO2.

To help people living in villages, I made this solar light bulb for providing a low cost solution by replacing their harmful kerosene lamps.This will empower the world’s poor to replace kerosene with clean solar-powered light.I got inspiration from NOKERO.

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.

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 2000mah AA battery can be charged fully in two days bright sun light.You can use the hanger as well as the multi purpose stand for charging.Just hang it on a wire out side or place it at your window.

3. Uses high quality AA NiMh battery which can work at least for 5 years.

4. Uses a high quality solar panel 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 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.

Uses :
1. Night Lamp

2.Reading Lamp

3.Portable Emergency Light

4.Camping and Hiking Lamp

5.Garden/Lawn Light



1.Solar Panel ( 2V,40mA or 2V 150mA or 2V,300mA )

2. 0.5W Straw Hat White LED ( eBay )

3. Rechargeable AA / AAA battery ( amazon )

4. IC QX5252F (eBay )

5. 33uH Inductor ( eBay )

6. Switch ( eBay)

8. AA / AAA Battery Holder ( eBay )


10.Prototype Board

11. Plastic Container

12.Aluminium Hanger

Note : Choose any one from the three solar panel mentioned.


1.Soldering Iron

2.Hot Glue Gun


4.Wire Stripper and cutter

Step 2: Schematic and Working:

The heart of this light bulb 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.

Most of the solar garden light uses this small intelligent chip.I came across these ICs when one of my Instructable friend talk me about this and send the data sheet and information.

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 3: Bread Board Testing

Before soldering the Circuit,It is always a good idea to prototype any circuit on a breadboard. This lets you check to make sure that all of your components are working perfectly.

Make the circuit on your bread bard as per the schematic.The LED should not glow if the circuit is correct.

To simulate the dark condition,cover the solar panel with your palm.Now the LED should glow.

Step 4: Out Put Waveform and Observation :

To check the performance of the circuit, I remove the LED and hook up my Oscilloscope probe.

The output is not a steady DC voltage but a voltage that fluctuates rapidly.In my case the frequency is around

184.5 KHz. The peak to peak voltage is nearly 7.28 V and the average value is around 1.0 to 1.20V.

Note : If you try to measure the voltage by a normal meter,it will show near to your battery voltage.Because your meters only measure the average value of a fluctuating voltage.

Step 5: Parts Selection :

1. Battery :

You can use any AA or AAA rechargeable battery.As per my experience I can sayeneloopbatteries are the best one.They are sold in pre-charged condition, so that you can use it directly after purchasing just like an standard alkaline battery.It can be reused up to 2100 times. When they weren't in use,could hold their charge for a lot longer than traditional NiMh battery.It can hold 70% charge after 5years of use.

For more details on eneloop batteries click here

Though a standard alkaline AA battery also works,but you can not charge the battery from solar power.

2. Solar panel :

Rating : A 2V solar panel is perfect for charging a AA NiMh battery (1.2v).Along with solar panel voltage,the current rating is also very important.Higher the current rating quicker the battery will charge.

I used a 2V,150mA solar panel.Choose according to your choice.

Size : Be sure during buying that the size of the panel is perfect to sit over the lid.In my case it is 55.1x55.1x3.59mm

3. Inductor :

The LED brightness can be controlled by using different values of inductor.

As per data sheet LED Power =( 2* Vbat / L )* 10^-6

As per my observation 33uH and 47uH works good for these 0.5W straw hat LED.

You can also try with other value and let me know which value works good for you.

3.LED :

I used a 0.5W stray hat white LED.It produce very bright light.I can say a single LED with fully charged battery is enough for basic lighting need.For specification of the LED I used is shown in the above picture.

You can also use a standard white LED but it will not produce sufficient light.

Step 6: Drill Holes for Hanger

Drill two holes diametrically opposite, near the top portion of the container.

It will used for mounting the hanger.

Step 7: 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.

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 8: Make the Multi Purpose Stand

Now it is time to use the straight part of the hanger.

First bend it at the centre.

Then make two folds 9cm away from the centre.

Make two folds at the end with length 1.5cm each.

Insert the plastic container at both ends and finally cover the lid.

This stand is very useful for

1. Charging : During charging you can change the orientation of the solar panel to get maximum sun light.

2. Lighting : To focus the light you can change its facing.

Step 9: Solder the Components

In order to make the finished circuit, I soldered the components onto a perforated board.

I have attached a PDF copy of schematic.You can use it during the soldering.

Step 10: Solder the Solar Panel Terminals

All the solar panel have pre marked terminals polarity.One is positive (+ ) and other is negative ( - ).

Solder a red and a black wire to the positive and negative terminals of the solar panel respectively

Step 11: 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.

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 12: Mount the AA 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 13: Connect a Switch

Trim the battery holder's red wire in two parts. Solder the trimmed pieces to the centre 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 14: Connect the Solar Panel and Battery to the Circuit

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 15: Mount the Circuit Board and Switch

Apply hot glue at the centre 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 16: Insert the Battery

Insert the battery into the battery holder.

Step 17: Finishing

To test the lamp slide 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 keep 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.

If you enjoyed this article, don’t forget to pass it along!
Follow me for more DIY projects and ideas. Thank you !!!

<p>Hi Deba;</p><p>Very nice work. into the hands of health. </p><p>Where PCB we find?</p><p>Thx.</p>
<p>Hello </p><p>Now I do not have any stock of PCBs.</p><p>If you need ,please tell me the numbers, I will order for you.</p>
Can you provide me complete light ?How much it will cost?
<p>No I don't have. I can send the PCB and components excluding the enclosure and battery</p>
<p>hi deba </p><p> my 9 year old is interested in doing something like this for his science project. How can we acquire PCB's from you ? do you have an ebay account were i can purchase them from you ?</p><p>best regards </p><p> my so</p>
<p>Hi</p><p>I am very happy to know that your son is interested on this project.</p><p>I don't have any eBay account.I will suggest to make the circuit on a perforated board as explained in this Instructable step-9 .During the making, if you face any difficulty, I am ready to help.</p><p>If you still interested to take the PCB, I can send it through post.But the problem is that it will take lot of time to reach.</p>
<p>Hi Deba,</p><p>Thank you for this very useful and practical project. In fact, I want to build several for my family. However, I do not know where to get the PCB. Do you sell these PCBs? If you do, I want to buy several. If not, can you point me to a good source. Thank you.</p><p>Pancho</p>
<p>Thanks for kind words.</p><p>Can I know how much PCB do you need ?</p><p>You can pm regarding it.</p><p>Thanks</p>
<p>HI Deba, </p><p>can you expaim me this? thx</p><p>When VLS is higher than 0.3 * VIN, the light control switch shuts the LED off, when VLS is lower<br>than 0.22 * VIN, the light control switches LED lights on.</p>
Hi Deba,<br>I would like to order initially 10 pcs only. May I ask if you have minimum number of pieces to order? Please let me know.<br>I hope you ship to the Philippines.<br>Kind Regards,<br>Pancho
Hi,<br>Thank you for the prompt response. I need initially around 10 pcs. How much would that cost me? Will you ship to the Philippines?<br>Kind Regards,<br>Pancho
<p>Hi Deba,</p><p>I am from Maharashtra. I have a few questions.</p><p>1) Where can I get the IC QX5252F in India. </p><p>2) If you have some spare IC's, can you sell ? </p><p>3) How much was the project cost in Rupees ?</p><p>Very nice ible and regards,</p><p>mahesh.</p>
<p>It is difficult to get in India.I have spare, I can give you one and no need to pay. </p><p>The cost is around 300 -350INR.</p>
<p>Hey </p><p>Can i get one too? (Im ready to pay)</p><p>I need only one and instead of buying 10 for Rs 350 and let the 9 go wast i thought it might be beneficial to get just one from somone who has a spare</p>
<p>Hi,</p><p>I can send one.</p><p>You have to pay the shipping charge.</p>
<p>Dear friend,</p><p>i also made some lantern based on same consent. but instead of using this IC i use transistor. i don't know its drawback please mail me then i can share my product details with you. my email id is ninadt23@gmail.com</p><p>please check my product photos </p>
<p>Wow ! Great looking.</p><p>Thanks for sharing the pics.</p><p>You can send the details opengreenenergy@gmail.com</p>
<p>Thanks Deba and so nice of you.<br>I will let you know where to send the IC and of-course will pay the shipping charges.<br>Also, may I request you to join my forum at www.posesnap3d.com/forum where I have created a special category for solar technology.<br>Thanks once again<br><br>Regards,<br>mahesh </p>
<p>Dear friend i am ninad i am also from Maharashtra.</p><p>i found substitute for this ic using transistor. Please contact mi my email id is ninadt23@gmail.com</p><p>to share knowledge to both of us </p>
<p>Hi there,</p><p>Nice clean work you did there! ;)</p><p>So, tell me, for the inductor, can I use all of the wattage range? 1/4W, 1/2W, 1W?</p><p>Or it must be 1/2W?</p><p>Kind regards</p>
<p>1/2W is more accurate.But you can use 1W also.</p>
<p>Did you make you PCB in Eagle CAD?</p><p>If yes, can you please provide me the QX5252F part name for library and also for that little switch.</p><p>Thank you! ;)</p>
Thank you for your quick reply! ;)<br><br>But also I noticed that in the LED driver IC's documentation, they are talking about 330uH inductor and you are using 33uH, is that correct?
<p>Hello Debasish,</p><p>A very ingenious idea, well executed.</p><p>Not wishing to belittle your efforts, which are quite admirable but in the<br>UK it is possible to purchase a solar powered light that is used for garden or pathway<br>illumination in local pound or 99p shops that will serve exactly the same<br>purpose as the unit you constructed. I know they can also be bought in the USA<br>in their dollar and 99cent stores. They usually have a battery incorporated<br>that charges during the day and the light switches on automatically at dusk. I<br>should think that they would serve the purpose you require either as is or with<br>minimal adaptation.<br><br><br><br>My reason for pointing this out is that, after reading the details you wrote on<br>your blog regarding the problems in rural India concerning the oil lamps that<br>are used, I though it would be so easy for one of the international charities,<br>or perhaps local governments within India, to provide or at least make<br>available such an inexpensive and simple unit that would improve life for those<br>concerned. Sometimes it is so easy of us in a more privileged situation to<br>overlook things that we take for granted, such as electric power to our homes<br>and all that means in improving our standard of living. There are many such<br>things that just do not occur to those in such a position, simply because we<br>have been fortunate to have them for so long that we are unable to envisage<br>being without them. We do tend to take so much for granted as is said.</p><p>I have read a number of your instructables, solar supply construction, solar<br>controller and others. You are a very knowledgeable and skilled individual and<br>have a knack of explaining things in a way that those of us who are not so<br>capable are able to follow, many thanks for that.</p><p>Keep up the good work.</p><p>Regards,</p><p>Rob.</p>
<p>Yes, easy to find solar lights for around a pound, but not so easy to find one at that price that gives off enough light to read by (the whole point of this tutorial), that will stay charged for more than an hour or two, or that even works at all. Out of a half dozen I bought from different pound stores to mark the edge of my decking, only two lit up even a little. To get an equivalent light to this the price tag seems to be &pound;5 minimum.</p>
<p>I agree, They go for 99cts here in the local thrift store. Got several of them that light up my garden at night</p>
help me to build 1 watt white led automatic solar light
<p>Hi Deba;</p><p>Or Schematic and PCB layers.</p><p>Send please my mail. </p><p>arifbudak@msn.com</p>
<p>Hi Deba,</p><p>Please can you tell me what I need to do so I can use a colour change LED. I have tried but it just glows red </p>
good job debasish!... ??<br>Voted!
Thank you :)
<p>Why you use inductor in instead of resistor. for apporse current we can also use resistor </p>
<p>Here the inductor role is not to limit current.The ic is very similar to a boost converter.The inductor is part of that circuit.Fore more details you can read the data sheet of QX5252F attached.</p>
<p>Dear Friends </p><p>Please tell me can any circuit using 6v 300mahSolar Panel and 3.6v Li Battery</p><p>anshulg22@gmail.com</p><p>Thanks</p>
<p>Sorry ,</p><p>Presently I don't have such circuit .</p>
<p>I'm having trouble getting to work. My 5252f ICs are 1302. Is there a difference between these and yours 1306? I've gotten the LeD to light when panel is uncovered and it's kind of dim..</p>
<p>That second row of numbers is a Date Code, usuallly [last two digits of Year, two digits Week Number 1-52], so 1302 is 2013, Week 2 (early January). 1306 is Week 6 (February).</p>
<p>I would suggest one change. One may wish to turn the light off, so I would mount the switch so that it can be operated without removing the lid.</p>
<p>Good Suggestion.But any idea, how it can be done ? </p>
The switches I ordered have tabs that can be fastened to the lid with small bolts, or glued. Cut a hole in he lid about 1/4&quot; by 1/2&quot; for the switch travel and drill two 1/8&quot; holes for screws.. Mount it using 1/8&quot; by 1/2&quot; screws and nuts. Once I assemble it, I will take pictures and send them to you.
<p>Could you please tell me from where i can get this PCB for making this project </p>
<p>Nice. There is never over-charge ?</p>
No still now I have not observed.
<p>Dear Deba168<br>I appreciate your work, kindly share a similar model with ambient light sensor.<br></p>
<p>Thanks Shrey,</p><p>The IC have inbuilt function of ambient light sensing.</p><p>So no need of extra sensor :)</p>
<p>hi i would like to know can we replace 5252F to another ic or tanistor?</p>
<p>I have not tried.</p>
<p>Hello deba,</p><p>Nice project !!!</p><p>Could you please let me know if I can use 5.5 V 500 mA solar panel with IC QX5252F to charge one 1.2 V AA NiMH batter?</p><p>If the AA battery gets fully charge will the IC QX5252F stop charging the AA battery?</p><p>Thank you</p><p>Best Regards</p><p>Ashutosh</p>
The panel is quite higher rating for QX5252F. But it will work. I can't say about the reliability. Good Luck :)
<p>Thanks for this nice instruction!</p><p>I changed the setup by separating the LED from the circuit/solar modul. It works perfectly :-)</p>

About This Instructable




Bio: I am an Electrical Engineer.I love to harvest Solar Energy and make things by recycling old stuffs. I believe &quot;&quot;IF YOU TRY YOU MIGHT ... More »
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