The output shaft of motor is rotated, which generates a voltage( in the range 12 V dc depending upon the speed of rotation of the motor shaft), since every motor is a generator and every generator is a motor. This generated voltage is given to the voltage regulator, IC 7805. It is used to get a constant output dc voltage of 5 V. For the IC to operate correctly, the input has to be greater than 7.2V. The input and output currents are the same. The power loss is dissipated as heat. We use this regulator as most of the smartphones are charged at 5V, 0.7 A. Capacitors of 1µF and 10 µF are used for better performance of the circuit. Diode IN4148 is used to ensure that the current flows only in one direction. Micro B usb port wire is used to charge the phone.
It provides an option for charging devices when users are not near electric outlet. It also provides the ability to power up a device while doing an eco-friendly activity like bicycling or skating. The pedal can be coupled with the motor shaft or can be driven by a belt. On pedaling, cycle pedal motion causes the shaft to move, which in turn gives the required torque for the motor to start and give the electrical output of around 12V. This can be given to the voltage regulator and the 5 V output can be used for charging. This can also be used to light the headlight of a cycle and in other applications to light the bulb by just applying mechanical energy.