In our world the rechargeabale gadgets have a very important role, but their batteries have a very low capacity, so they discharge fast. In this instructable I gonna show you how to build an USB device charger, that is powered by a solar panel, or a wind/hydro turbine. It contains a rechargeable power bank, which you can charge up your phone everywhere. This instructable is divided to parts… If you don’t want to make the full project, just go to another part. Part 1 is the rechergeable power bank, that uses two AA rechargeable batteries. The Part 2 is a solar USB charger, that can charge the power bank too, and third part is hydro/wind turbine battery charger, which can be connected to a faucet, and genarates electricity. This turbine also can be connected to your bicycle, and works as a wind turbine. The instructable was made for the 15th MILSET Expo-Sciences International contest and for the Make Energy, so if you liked vote on me. With this gadget you can save more than 50$ per year, but this money goes to my parents:).The idea is easy, but you will need some experience in electronics, and in DIY projects to make this gadget. So let’s begin, I hope you like it…
Step 1: Tools and Materials
1. soldering iron and solder
2. glue gun
3. desoldering pump (optional)
4. electrical tape (optional)
5. rotary tool or driller
PART 1: Rechargeable Power Bank
• old casette box, or a simple plastic box
• 2 AA size Ni-MH rechargeable batteries (at least 2000mAh)
• battery box, or you need to connect somehow the batteries in series, like me with the electrical tape
• 9 volt battery clips, I love them, because they can be used as connectors, but you can use others
• if you can buy, get a 5v USB step up charger, but if you can’t get these circuit components: TL496 IC, 46uH inductor, 10uF capacitor, a 5.1v zener diode and a female USB jack, (with these compononents you can make a 5v step up circuit)
• 7805-5v voltage regulator for charging the NiMH battery
• 47uF apacitor, and a germanium diode
• 2 switches, and 2 super bright LED-s
• male USB jack (if you want to charge the power bank from your wallplug phone charger)
• PCB board
• 2 switches
I didn’t use a NiMH charger circuit, just calculated the charging time (hour=capacity/current). With my 170mA solar panel this is 11 hours, so I can not leave the batteries in charger for more than 12 hours, because they will overcharge.
PART 2: USB and battery charger Solar device
• 5.5v solar panel, or better (you will need at least 5.5 volts)
• old CD
• 7805-5v voltage regulator for charging the phone
• female USB jack
• 9 volt battery clip (with this you can charge the NiMH batteries
PART 3: Hydro/Wind turbine charger
In this part you’ll need to make a Joule Thief for small generator. If you want to read more about the Joule Thief, click here.
• NPN transistor (2N2222, 2N3904 BC547 equivalent)
• ferrite core (from an old CFL bulb)
• #24 AWG wire
• small motor (you can find in a RC helicopter)
• 50 ohm resistor
• PCB board
• PVC tube (the diameter needs to be so big, with you can connect to your faucet)
• plastic sheet (white or transparent)
• metallic grey paint (optoinal, but on your faucet will look much better)
• 9 volt battery clip
• germanium diode
This generator can’t charge directy your phone, but generates 100mA and more than 3 volts, that is more than enough to charge NiMH or NiCd batteries or the rechargeable power bank from the PART 1. And if the power bank is charged you can charge your phone, tablet, or GPS. Before we begin the building I need to tell you, that a simple American family uses 600 liters of water per day. This means about 1.5 hours flowing water from your faucet, and if you use this hydro turbine you can give for your battery 0.13 volts per every 1.5 hours. So a NiMH 2000mAh battery can not be charged so fast, but after 1 day you can charge your phone for about 30-25% with a 5v booster. I think this would be a great household item, because it is small, and 100mA from a small motor like this is very good, so… start building.
Step 2: PART 1: Rechargeable Power Bank
The first step is to make the box of the project. I’ve used a dremel tool to cut every holes. You must to cut a hole for the female usb jack, for the 9v battery connector, and 2 smaller holes for the switches and 2 more small holes for the 2 LEDs. I love transparant design, so I usually use a transparent project box. It looks great the circuit inside, and if happens a somethimg inside I can see what is the problem.
Step 3: PART 1: Soldering and Glue
The circuit is designed by me, but works good. I’ve put a switch after the germanium diode, and to the 5v output I’ve soldered 2 LEDs in paralell with a switch. To the 5v output is soldered the USB jack. The TL496 is a 9v up stepper IC, that’s output is regulated by a 10uF cap, and with a 5v1 zener diode. This gives 5.35 volts, that is enough for a mobile phone.The safest way is, if you buy a 5v step up circuit. On the last image is a male USB connected to a 9v battry clip… This is a charger for the power bank, that’s not green energy, but useful for fast charging from a comuter or from wallplug. The input to charge the batteries (9v clip) is reversed, see on 4th photo. The 9v clip’s negative connection is soldered to the positive and the positive to the negative. There you can see a 7805 voltage regulator, and a 47uF capacitor with a germanium diode. Theirs role is to ensure the proper charging. you can give him a voltage up to 30 volt AC/DC. If your circuit is done get a glue gun and fix everything, but test it before. Bring your personality in the design, that makes your gadget especial. Think different!
Step 4: PART 1: The End and potential problems
If the circuit won’t work read this article. Check every connections, and the legs of the IC . If the voltage is small try with another capacitor or the last way is the 5v up stepper from the ebay. If works plug your phone in, and test how many percent can charge. You can incease the percents with batteries that have higher capacity. If you’ve liked read the PART 2. If you have an Apple device visit this webpage. Here is written how to make a circuit with some resistors, that can charge an iPad, iPod or iPhone.
Step 5: PART 2: Solar Charger
For the box I have used a transparent CD case. In this part the dremel has a very important role. Remove everything from the CD case, make it smooth. You must cut a hole for the solar panel. Glue there the solar panel, and clean it. After this cut two other holes for the USB jack, and for the switch. You can see these holes on the second photo. It is an easy and a nice design. Saves the circuit and the other materials, but is slim and small, you can hold almost everywhere (on your jacket, satchel, bag, besides the window, where the Sun is shining, etc.).
Step 6: PART 2: Soldering
The circuit is very simple, uses only a switch and a 7805 voltage regualator. The psitive wire of the solar panel is soldered to the center of the switch. To the rigt side solder the positive 9v clip, and to the left side the positive input of the 5v regugator. If the switch is in center the circuit is turned off, if is in the right you activate the the regualtor and if is in the left side the current flows to the 9v clip. Trough the 9v clip you can charge up the power bank. Before glue test it, and if works fix everything .
Step 7: PART 2: Testing
You can’t see on the images, but my phone is charging. The 9v clip can be used as a supporter too. You can charge even tablets, but it needs at least 5 hours. My room’s windows looks southwards, so I can charge my phone anytime with green energy (of course when Sun is shining). I use my phone only for callings and for browsing sometimes, so the battery discharges slowly, but when is “dead” I can charge up with this gadget. Please do not misunderstand, don’t want to be boastful, I’m trying to tell you somehow, that green energy is cool.
Step 8: PART 3: Hydro/Wind turbine on your faucet
You may see many DIY solar and power bank chargers, but this hydro turbine is very particular, because you can’t buy this in shops, this is a new invention. The base of the gadget is the Joule Thief circuit, that, is builded from a few components. On the circuit you can see, that the power source is the M (motor, with a propeller on it) and the usually used 1k is switched to a 50 ohm resistor. The role of the blocking diode is that don’t allows that the current flows backwards. In the link at the materials is described detalied the Joule Thief. If the circuit has worked on the breadboard solder everything together.