Bicycle Cell Phone Charger (Wind Turbine with build in Battery)

I go very often to cycle in the nature where is no electricity, and during a long bike tour my phone usually discharges. These smartphones have a large capacity but its consumption is big too. I made a few weeks ago another bike turbine for the Bicycle Contest, but I think I can make a better one. So created an all in one wind turbine power bank.

I like to combine cycling with electronics (these are my favorite hobbies) so that's why I create so much bike gadgets now for the Bike Contest.

This project requires basic soldering experience and
some patience.

The price of a device like this is very high on the eBay, 112 bucks!!! Click here if you want to see. OK, my one can't light and isn't so smart but this price on the eBay is ultrahigh. 


The gadget was made from scrap parts and from very cheap circuit parts. Now go gather materials!

STEP 1: GATHERING TOOLS AND MATERIALS

Tools
• Soldering Iron
• Glue Gun
• Wire Stripper and Cutter
• Electrical Tape


Materials
• an old CPU fan
• toroidal inductor
• 2N2222 or 2N3904 or BC547 transistor
• 5v step-up module, (boought on eBay)
• germanioum diodes (5 pieces)
• a small perfboard
• an old phone battery or a 18650 cell
• and a small switch
• bike support element


And that's all. The fan generates AC current that we'll convert to dc current to charge up the battery via a Joule Thief circuit.The Joule Thief gives enough voltage boost for the build in Lithium ion battery. I don't use a charger circuit, because this current isn't enough to damage the battery.

STEP 2: AC TO DC

First take off the propeller, because we need to find two pins that gives the highest AC voltage. You can see three pins inside the fan. Solder to each one wire then check with a multimeter (in AC mode) that which two gives the best voltage. Remove the third wire that is unusable.

Put back the propeller, and create a diode bridge just like on the images. Connect this to your compter fan. Now the gadget could generate 4 volts and 60mA, that's almost enough for charging the li-ion battery. But using a joule thief we can get a very cool voltage for our battery.

STEP 3: JOULE THIEF

This step is pretty easy. Simply solder together the well-known Joule Thief circuit. If you're done connect it to the DC output of the CPU fan.

On the diagramm the 1.5v single battery means the CPU fan. And the LED means the battery.

STEP 4: THE CHARGER UNIT

Hook up your battery and connect it to the 5v step-up module. Place between these a power switch. Connect this thing too to the Joule Thief's output. Now the circuit is done and device can be used, but we'll need to make them nicer.

STEP 5: GLUE!

Get your glue gun and fix everything on the CPU fan's sides.

STEP 6: WATERPROOFIG

Using some electrical tape waterproof the system. It isn't the best solution but do his job.

STEP 7: TESTING

The pictrure qualty is not the best but on the third picture you can see that it works. If works for you too go and put on your bike.

STEP 8: SETTING UP TO THE BIKE

Get a bike support element and glue oon the top of the device. Now you're done.

STEP 9: HAVE A GOOD BIKE RIDE!

If everything works just enjoy the free energy of your bike.