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:
o Voltage source
o Capacitors
o Resistors
o Diodes (D4148)
o Transistors (MOSFET IR540)
o Transmitter coil

8. CONTD…
Receiver section:
o Diode (D4007)
o Resistor
o Voltage Regulator
o Receiver coil
o 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