Wireless electricity

Presentation is on wireless electricity and how to generate it.
Various methods to generate electricity wirelessly.
Experiment conducted in MIT

1. Presented by- Anushreya Gupta 1309020020 Branch:- Electrical Engineering Wireless Electricity

2. Overview Introduction What is WiTricity?? Principle Working Advantages Some other methods of wireless power transfer Future applications Conclusions

3. Introduction Computers , cell phones, laptops, iPods, etc. are all used by many of us in our daily lives. These devices have become an inherent part of our day-to-day lives. But charging all these appliances has become so very cumbersome. Each appliance has its own set of chargers, and with every family member owning their cell phones, the drawers are overflowing with all sorts of wires . How many times have you wished if there could be some way to do away with all the wiry litter? The answer is WiTricity

4. What is WiTricity??? WiTricity is nothing but wireless electricity. Transmission of electrical energy from one object to another without the use of wires is called as WiTricity . WiTricity will ensure that the cell p hones, laptops, and other power hungry dev ices get charged on their own, eliminating the need of plugging them in. Even better, because of WiTricity some of the devices won't require batteries to operate.

5. History The term WiTricity was used for a project that took place at MIT, led by Marin Soljačić in 2007. Researchers successfully demonstrated the ability to power a 60 watt light bulb wirelessly, using two 5-turn copper coils of 60 cm (24 in) diameter, that were 2 m (7 ft) away, at roughly 45% efficiency. The coils were designed to resonate together at 9.9 MHz (wavelength ≈ 30 m) and were oriented along the same axis. One was connected inductively to a power source, and the other one to a bulb. The setup powered the bulb on, even when the direct line of sight was blocked using a wooden panel. Researchers were able to power a 60 watt light bulb at roughly 90% efficiency at a distance of 3 feet. The research project was spun off into a private company, also called WiTricity.

6. Experiment from MIT Pics from alternate angle Alternate Geometry

7. Principle behind WiTricity Based on strong coupling between electromagnetic resonant objects also called “Resonant Magnetic Coupling” Transmitter and receiver coils oscillate or “resonate” at the same “frequency”. Resonant frequency is the natural frequency of an object .

8. Two resonant c/ ts - Transmitter & Receiver. Each circuit has a  coil of wire connected to a capacitor, or a self-resonant coil or other resonator with internal capacitance. Two are TUNED to resonate at the same resonant frequency.

9. How It Works?

10. Advantages :- Charging multiple devices. Environmentally & Economically beneficial as it could drastically reduce 6 billion batteries disposed of each year which is a major cause of ground water contamination. Disadvantages: - High initial cost. Slow. Distance constraint. Near field method

11. Applications Electronic portable devices such as laptops and cell phones can be easily charged. Wireless charging of electric vehicles using MPT Wireless charging of wearables such as headphones, watches etc.

12. Some other methods of wireless power transfer FAR FIELD Microwaves (Microwave Power Transfer or MPT) Lasers NEAR FIELD Inductive coupling using electromagnetic induction

13. Qi (Inductive Power Standard) Qi  (pronounced  chee ) -Chinese word meaning “natural energy” An interface standard developed by the Wireless Power Consortium for inductive electrical power transfer over distances of up to 4 cm (1.6 inches). The Qi system comprises a power transmission pad and a compatible receiver in a portable device. To use the system, the mobile device is placed on top of the power transmission pad, which charges it via resonant inductive coupling. Qi logo

14. Nokia launched a wireless charger for it’s Nokia Lumia 920 in 2012 which uses Qi wireless charging standard

15. Conclusions Transmission without wires- a reality. Efficient. Low maintenance cost. But, high initial cost. Better than conventional wired transfer. Energy crisis can be decreased. Low loss . In near future, world will be completely wireless.

16. Thankyou !! presentation by Anushreya Gupta