Wireless mobile charger

This project explains a simple wireless battery charger circuit that charges your mobile when placed near the transmitter. 
This circuit may be used as wireless power transfer circuit, wireless mobile charger circuit, wireless battery charger circuit, etc.

1. Wireless Mobile Battery Charger 

2. Contents: Introduction Principle Circuit Diagram Block Diagram Components Description Working Advantages Disadvantages Applications Conclusion

3. Introduction Emerging technologies are making our life simpler these days. With the introduction of mobile phones, life has changed rapidly.  This project explains a simple wireless battery charger circuit that charges your mobile when placed near the transmitter.  This circuit may be used as wireless power transfer circuit, wireless mobile charger circuit, wireless battery charger circuit, etc.

4. Wireless Battery Charger Circuit Principle This circuit mainly works on the principle of mutual inductance . Power is transferred from transmitter to the receiver wirelessly based on the principle of “inductive coupling ”. “Mutual inductance” is the phenomena in which, when a current carrying conductor is placed near another conductor voltage is induced in that conductor.

5. Contd … This is because, as the current is flowing in the conductor, a magnetic flux is induced in it. This induced magnetic flux links with another conductor and this flux induces voltage in the second conductor. Thus two conductors are said to be inductively coupled.

6. Wireless Mobile Charger Circuit Design

7. Components Transmitter section: Voltage source Capacitors Resistors Diodes (D4148) Transistors (MOSFET IR540) Transmitter coil

8. Contd … Receiver section: Diode (D4007) Resistor Voltage Regulator Receiver coil Capacitors

9. Block Diagram

10. Working The first circuit is transmitter circuit used to produce voltage wirelessly. The transmitter circuit consists of DC source, oscillator circuit and a transmitter coil. oscillator circuit consists of two n channel MOSFETS  IRF 540 , 4148 diodes. When the DC power is given to the oscillator, current starts flowing through the two coils L1, L2 and drain terminal of the transistor.

11. Working At the same time some voltage is appeared at the gate terminals of the transistors. One of the transistors is in on state while the other is in off state Thus voltage at drain of transistor which is in off state raises and it fall through the tank circuit made of 6.8nf capacitors and transmitter coil of 0.674. Thus operating frequency is determined by using formula F=1/[2π√(LC)].

12. Working In the second circuit that is receiver circuit consists of receiver coil, rectifier circuit and regulator. When the receiver coil is placed at a distance near the inductor Ac power is induced in the coil. This is rectified by the rectifier circuit and is regulated to DC 5v using 7805 regulator. The rectifier circuit consists of 1n4007 diode and capacitor of 6.8nf. The output of regulator is connected to the battery.

13. Advantages Usage of separate charger is eliminated . Phone can be charged anywhere and anytime . It does not require wire for charging. Easier than plug into power cable.   Easy to operate and it is environmentally friendly.

14. Dis Advantages Low efficiency compared to the wired charging method. Extra heating. The wireless mobile charging circuit is more complicated than the traditional charger. The cost is comparatively higher than the wired charger.

15. Applications Wireless Power Transmission Circuits can be used to charge camera batteries, mobile phones, wireless mouse, bluetooth headset etc. Future development in this Wireless Power Transmission technology like witricity (wireless electricity) will allow charging of car batteries, household equipments, medical devices and other devices to charge wireless instead of wires.

16. Conclusion The technology provides a wide range of other benefits , including better portability. This method provides great advantage to the mobile phone users to carry their phones anywhere even if the places is devoid of facilities for charging