Inductive Power Transfer
Group 10 Muralidhar Konda Shourie Reddy

OBJECTIVE
● The main aim of the project is to design and construct a method to transfer wireless Electrical Power to charge a low power device so as to reduce the usage of “wires”. ● Another application would be to include charging of multiple devices using a single source .

SPECIFICATIONS
● High frequency (upto 100-500 KHz) ● High Efficiency(40-50%) which can be achieved by increasing the coupling between the transmitter and receiver. ● The range should not be less than 10 cms. ● High current(500mA or more).

METHODS
There are different methods by which power can be transmitted wirelessly. Some of them would be ● Using Inductive Coupling for short range. ● Resonant Induction for mid range. ● Electromagnetic wave power transfer for high range.

TRANSMITTER MODULE
● The transmitter module of our project is made up of a D.C. power source, an oscillator circuit(royer oscillator in our case) and a transmitter coil. ● The D.C. power source provides a constant D.C. voltage to the input of the oscillator circuit. There, this D.C. power is converted to a high frequency A.C. power and is supplied to the transmitter coil. ● The transmitter coil, energized by the high frequency A.C. current, produces an alternating magnetic field.

ROYER OSCILLATOR

FREQUENCY MODIFICATION
● The oscillator runs at the frequency determined by the inductance of the coil and the capacitor value ● The operating frequency is the familiar formula for resonance. ● W=1/sqrt(LC) ● F= 1/(2 × π × sqrt(LC)).

SIMULATION RESULTS

SIMULATION RESULTS

RECEIVER MODULE
● The receiver module of our project is made up of a receiver coil, a rectifier circuit and a voltage regulator IC. ● An A.C. voltage is induced in the receiver coil. The rectifier circuit converts it to D.C. and the voltage regulator IC helps to maintain a constant limited voltage at the load.

DIODE BRIDGE RECTIFIER

RECEIVER CIRCUIT

SIMULATION RESULTS

RESULTS
● By giving a Dc voltage of 13 V at the input,plots of power efficiency and current were calculated by varying the distance between the two coils. ● From the observations we concluded that charging of a mobile can be done upto a maximum range of 4cm, while LED can be lit upto a maximum range of 10cm.

CURRENT-DISTANCE

POWER EFFICIENCY-DISTANCE

PROBLEMS AND SOLUTIONS
● In our project the main goal was to design and implement a system that transmits power to charge low power devices without wire. In this purpose, a transmitter circuit was implemented. ● At the end of the transmitter circuit a coil was connected, which transmits the power. Another coil was used to receive the power wirelessly from the transmitter circuit. ● In this project, the coil was made with a copper wire(1.7mm thickness).Initially we used a copper wire with less thickness but we opted for a wire with higher thickness as it can tolerate higher currents.

PROBLEMS AND SOLUTIONS
● Efficiency increased when the two coils were parallel to each other as it results in higher transfer of power. ● To transmit the power to a greater distance, a high power radio frequency amplifier connected with an oscillator is needed which is costly and requires more time. ● The frequency at which our circuit was operating was 600700 KHz.

APPLICATIONS AND BENEFITS
● Any place where wires have a role to play, they can be replaced by this method. ● Cost Efficient. ● Convenient and Simple. ● No moving/mechanical Parts. ● Multiple Receivers from a single transmitter.

MODERN WIRELESS CHARGING
● A transmitter unit comprises a primary coil, which creates a magnetic field by applying an alternating current to a winding, coil, or any type of current carrying wire. ● A receiver comprises a means for receiving the energy from the alternating magnetic field and transferring it to a mobile or other device. ● For installing receiver circuit inside the electronic device initially the whole circuit has to be converted onto a chip.

TRANSMITTER BLOCK PROTOTYPE

RECEIVER BLOCK PROTOTYPE

COMMERCIAL POSSIBILITY
There is already huge demand for wireless power transmission system. Mostly the renowned electronic giants like Sony, Samsung, Panasonic, Toshiba, Apple and Bose etc. have shown huge interest in this technology. It could be the future of the world.

Thank You