Charge your phone using a dc motor or bicycle generator

In Jamaica especially during the hurricane season we are going to experience lost of electricity and most of us would still like to be able to charge our phone and our neighbours' phones (at least). Well if you have a small motor to make a quick and easy wind turbine or if you have a bicycle with a generator on it, the following circuit can be attached to same and then used to charge your phones.

This device will work to power not only a mobile phone, but anything which requires 5V. Of course, it’s pretty easy to swap out the L7805 for any other similar voltage regulator.

Resources Required

This device was very cheap to make, probably $500 worth of parts (that is if you dont already have them at home). 

1. L7805/7805 voltage regulator
2. 100 µF electrolytic capacitor
3. 10 µF electrolytic capacitor
4. 1N400x rectifier diode 
5. the dc motor usually found in old toys or a bicycle generator 
6. USB cable 

Procedure

Take a look at the following circuit diagram, it’s very simple to follow and understand. Notice the diode which ensures current flows in only one direction (we don’t want any mishaps). Of course, diodes do have a drop voltage, but it’s low enough to keep everything working great. Then we have two decoupling capacitors to smooth out the voltage coming in, and going out. Of course, we have the 7805 which regulates the voltage. The IN pin accepts the inward voltage, the GND pin connects to the negative terminal of the voltage source, and OUT delivers the outbound voltage.

Caution

Only attempt if have at least the basics in electronics.

Reference: Tree House Projects