Nowadays mobiles can also be charged using the USB outlet of PC. The mobile charger circuit presented in this project can give 4.7V of synchronized voltage [[wysiwyg_imageupload::]]for charging the phone. As USB outlets can give 5V DC and 100mA of current. It is sufficient for slow charging of mobile phones so they can be used to charge the mobile phones. USB stands for Universal Serial Port. It is one of the latest methods to exchange information from PC to the real world. The USB port offers power to the external devices. +5V of power is available at pin1 and -5V of it is available at pin4. Most of the Mobile Phones battery are rated 3.6 volts at 1000 to 1300 mAh. These battery sets have 3 Lithium cells which have 1.2 volt rating. Keep on reading to find out how the circuit is constructed and how it works.
In this project a mobile/battery charger is made by using voltage divider rule. Voltage divider is also known as a potential divider. Potentiometer having two resistor in it is the best example of a voltage divider rule. This charger has reference voltage lower than the input voltage. Using voltage divider any voltage can be derived by it by passing high voltage than the voltage we want. This is because output voltage which comes out is always lesser. Voltage dividers are used for adjusting the level of a signal, for bias of active devices in amplifiers and for measurement of voltages. A Wheatstone bridge and a multimeter both include voltage dividers. A potentiometer is used as a variable voltage divider in the volume control of a radio, in finding temprature, in battery charger, in loud speaker etc.