Cell Phone Charger Project Presentd By: Ms. Afnan Fahad

Outline Circuit Diagram…………………………………….. Description…………………………………………… Step Down Transformer………………………….. Capacitor……………………………………………. Diode…………………………………………………. Resistor………………………………………………

Cell Phone Charger

Circuit Diagram

Description This simple circuit can give regulated 12 volts for charging a mobile phone. Most of the Mobile Phone batteries are rated 3.6 volts at 1000 to 1300 mAh. Usually the battery pack requires 4.5 volts at 300-500 mA current for fast charging. low current charging is better to increase the efficiency of the battery.

Step down transformers are designed to reduce electrical voltage. It becomes necessary when you wish to use a product needing 110v where the main supply is 220v. As a rule, a step-down transformer is a transformer whose secondary voltage is less than its primary voltage.

Capacitor

A capacitor is a passive two terminal electrical component used to store energy in an electric field. The forms of practical capacitors vary widely, but all contain at least two electrical cinductor separated by a dielectric (insulator).

Diode

A diode is a two-terminal electronic component with asymmetric transfer characteristic, with low) resistance to current flow in one direction, and high resistance in the other. The most common function of a diode is to allow an electric current to pass in one direction (called the diode's forward direction), while blocking current in the opposite direction (the reverse direction).

Resistor

A resistor is a passive two terminal electrical component that implements electrical resistance as a circuit element. The current through a resistor is in direct proportional to the voltage across the resistor's terminals.