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Submitted By:-Rahul Shrimali
ECE 4th Year
TECHNO INDIA NJR INSTITUTE OF TECHNOLOGY, UDAIPUR
ATechnical Seminar Presentation
On
“WITRICITY- WIRELESS ELECTRICTY”
Seminar Guide:- Mr. Abhishek AcharyaLecturer Electronics & Communication TINJRIT,( Udaipur )
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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.
Because of Witricity some of the devices
won't require batteries to operate.
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.
WIreless elecTRICITY
†The story started late one night a few years ago.
†It was probably the sixth time that month that MIT
Professor Marin Soljacic was awakened by his mobile
phone beeping battery low.
†At that time it occurred to him that there is electricity
wired all through his house, office-everywhere. He think
about- how it is possible to use electricity without using
wires…
Story behind WITRICITY
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basics
electricity
magnetism
Energy coupling
Magnetic induction
Electro magnetis
m
Resonant magnetic coupling
resonance
Basics of WITRICITY
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The Transfer of Electricity from one place to another without wires is known as “Witricity”.
There is witricity power sources(transmitter) and capture devices(receiver).
Power source provides power to the devices where as capture device captured it to work.
Power source and capture devices are specially designed magnetic resonators.
Magnetic resonators efficiently transfer power over large distance via the magnetic near-field.
WITRICITY TECHNOLOGY
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Near field Near field is a wireless transmission technique over distances
comparable to or a few times the diameter of devices.
Near field is usually magnetic field.
Near field energy is non radiative, but some radiative and
resistive losses will occur.
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Coupled resonators Two resonant objects of the same resonant
frequency tend to exchange energy.
It exchange energy strongly ,while interacting weakly with living beings and other environmental objects.
Coupled resonators are said to be operate in strongly coupled regime to avoid material absorption and radiative loss.
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Strong coupling
Strength of interaction is very high.
Energy transfer is very efficient.
The rate of energy transfer is
substantially higher than rate of
energy lose.
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MIT teams behind witricity technology
The first experiment of witricity, the concept of wireless electricity,
was conducted in the year 2006, by researchers from Massachusetts
Institute of Technology. The Assistant Professor of this team of
researchers was Marin Soljacic.
2007: A physics research group, led by
Prof. Marin Soljacic,at MIT, wirelessly
power a 60W light bulb with 40%
efficiency at a 2 meters (6.6 ft) distance
using two 60 cm-diameter coils
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Diagram of power source and capture device
Power source is connected to ac power.
Bulb is connected to capture device.
Blue lines represent the magnetic near field induced by the power source.
Yellow lines represent the flow of energy from the source to the capture coil.
This powers light the bulb.
The magnetic field can wrap around the obstacle between power source and capture coil.
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Witricity technology is more than…
Traditional magnetic induction.
Radiative power transfer.
Tesla’s vision of a wireless world.
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Used in power transformers. conductive coils transmit power to each
other wirelessly, over very short distance.
Traditional magnetic induction
An electric tooth brush uses traditional magnetic induction to recharge its batteries
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If Radio frequency energy is used for wireless power transfer.
Radiated power is wasted into free space Need line of sight. Harmful.
Radiative power transfer
Microwave oven utilizes radiation to cook foods
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Tesla’s vision of a wireless world
Nikola Tesla the most well known scientist had a vision of wireless world.
In which wireless electric power and communication would reach around the world, delivering information and power.
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Features and benefits
Non radiative energy transfer
Safe for living beings and other environmental objects
Flexible geometry Device that can fit into OEM (original equipment manufactures)products
Scalable design From Mw to kW
Energy transfer via magnetic near field
Can penetrate and wrap around obstacles
Highly resonant strong coupling
High efficiency over distance
Witricity’s Technology Technology Benefit
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Witricity technology can provide…
Direct wireless power-within the range of witricity power source
Automatic wireless charging- both in and out of range of its witricity power source.
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Applications
Consumer electronics
Industrial
Transportation…
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WITRICITY APPLICATIONS
Automatic wireless charging of
mobile electronics in home, car,
office,...while devices are in use
and mobile.
Direct wireless powering of
stationary devices…eliminating
expensive custom wiring,
unsightly cables and “wall-wart”
power supplies.
CONSUMER ELECTRONICS
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Robots, package machinery,
assembly machinery, machine
tools.
Direct wireless power and
communication interconnections
at points of use in harsh
environments.
Direct wireless power for wireless
sensors and actuators, eliminating
the need for expensive power
wiring or battery replacement and
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INDUSTRIAL
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Application continues……………
Automatic wireless charging for existing electric vehicle classes: golf carts, industrial vehicles.
Automatic wireless charging for future hybrid and all-electric passenger and commercial vehicles, at home, in parking garages, at fleet depots, and at remote kiosks.
TRANSPORTATION
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ADVANTAGES
No need of line of sight.
No need of power cables and
batteries.
Does not interfere with radio waves.
•Wastage of power is small
•Negative health implications.
•Highly efficient than
electromagnetic induction
•Less costly.
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Wireless power transmission can be possible only in few meters.
Efficiency is only about 40%.
Disadvantages
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FUTURE OF WITRICITY
Teams’ next aim is to get a robotic vacuum or a
laptop working, charging devices placed any where
in the room and even robots on factory floors.
In another 3 to 5 years time. they will come up with
a witricity for commercial use.
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REFRENCES
An article published in the Science Magazine as “Wireless Power Transfer via Strongly Coupled Magnetic Resonances” by Andre kurs, Science 317, 83(2007); Dol:10.1126/ science.1143254.
H. Haus , “Waves and Fields in Optoelectronics”, Prentice hall Publishers, Englewood
http://electron9.phys.utk.edu/optics507/modules/m6/coupled_resonators.htm
“Efficient Non-Radiative Midrange Energy Transfer” by Aristeidies karalis, Marlin Soljacic.
Nikola Tesla, My Inventions, Ben Johnston, Ed., Austin, Hart Brothers, p. 91,1982.
Thomas F. Valone, “ Tesla’ s Wireless Energy... For the 21st Century!!! One Step Beyond Direct TV!!!” Extra Ordinary Technology, 1, no. 4, Oct / Nov / Dec 2003.
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