Mobile charger circuit design

 Mobile Charger circuit diagram

Objectives:

Ø  Designing  a mobile charger cheap in price.

Ø  Supported by  both AC and DC power supply.

Ø  Less power loss.

Ø  Small size and easy to Carry.

Ø  To present a charger that is good , efficient and better longevity to the society.

Apparatus:

ü  Transformer (9V AC,600mA)

ü  Diode(1N4007)-4 pieces

ü  Capacitor(100uF,50V)                      

ü  IC(LM7806CT)

ü  LED(3 pieces)                                                             

ü  Resistor:                                              

    R1=47

    R2=10R                      

ü   Clips(2  pieces)                                         

ü  Jack & holder

ü  Breadboard

ü  CCB board

Working  Procedure:

According to our circuit ,when we are using  AC power supply as input, the transformer steps down 220V   to 9V AC. Then the bridge rectifies it and converts it into pulsating DC which gets filtered by the capacit - -or. This becomes the input for the IC that stabilizes the DC at 6V. Then LED1 in the circuit, not letting excess current flow to the ground (working as a small resistance), provides an increase of more than 2V to the stabilized 6V.This increased DC voltage is used to recharge our battery. In this circuit LED3 is used just to indicate the flow of current, charging the battery. Giving protect to this LED3 we have used a 10 ohms resistance in series with it and to add protection for overflowing of  current a resistance of 47 ohms is used in parallel to the LED3 and the 10 ohms resistance.

 When Battery is in use the LED2 only is to show the existence of current flow or to indicate that the power source is now in DC mode. Here the use of capacitor,IC,LED1,LED3,47ohms and 10 ohms resistance is same as AC operation.

 Result:

Data across NOKIA 5130-Xpress Music

A.      When  only AC  activate

Without  Load

·         Voltage across DB=8.91V

·         DC Voltage Across C1=13.72V

·         IC input=13.03V

·         Output Current=0.34mA

·         Output Voltage=8V

·         Power loss=23.33%

            With Load

·         IC input=9.46V

·         Output Voltage=6.8V

·         Output Current=0.12mA

·         Power loss=27.58%

·         Charging time=4hr

B.      When  only Battery  activate

Without  Load

·         Battery voltage=12.45V

·         IC input=12.53V

·         Output Current=0.34mA

·         Output Voltage=8V

·         Power loss=19.17%

            With Load

·         IC input=12.32V

·         Output Voltage=4.49V

·         Output Current=0.15mA

·         Power loss=27.58%

·         Charging time=4.5hr

C.      When  Duel

  Without  Load

·         IC input=13.03V

·         Output Current=0.34mA

·         Output Voltage=8.03V

·         Power loss=44.1%

            With Load

·         IC input=13.61V

·         Output Voltage=6.8V

·         Output Current=0.13mA

·         Power loss=50%

·         Charging time=4.5hr