Wireless electricity uses magnetic resonance to transfer electric power between two coils. It was first proposed by Nikola Tesla in 1899 but research was revived in 2007 by a MIT team led by Marin Soljacic. They were able to transmit power wirelessly over a distance of 2 meters at 43% efficiency using resonant inductive coupling of coils tuned to the same frequency. Wireless electricity has applications for charging consumer electronics, electric vehicles, and medical implants without wires and could reduce battery usage. However, the technology is currently limited to short ranges of a few meters and low efficiency compared to wired transmission.

1. Wireless Electricity”
FUTURE OF ELECTRICITY!!!

2. Why do we need wireless
electricity???
The ever increasing power demand
The need of electricity in every nook and
corner of the world
The demand of eco-friendly power
Requirement of efficient and reliable
power
To reduce dependence on wires and
batteries

3. History of Wireless Power:
 In 1899, Sir Nikola Tesla Proposed a
method of Wireless Power
Transmission.
 As it is in Radiative mode, most of
the Power was wasted and has less
efficiency.
 Tesla was able to transfer energy from one coil to
another coil
 He managed to light 200 lamps from a distance of
40km
 The idea of Tesla is taken in to research after 100
years by a team led by Marin Soljacic from
MIT. The project is named as „WiTricity‟.

4. Tesla’s ingenious design for the wireless transmission of
energy

5. The Witricity Team
1
In 2007,6 MIT members
headed by Marin Soljacic
were able to successfully
transmit power to a bulb
within a distance of 2m at a
freq of 9.9MHz using
concepts of
non radiative mid range
energy transfer
Resonance
inductive coupling
Efficiency at that point was
just approximately 43%

6. Experimental Design:
Our experimental scheme consists of two Self-resonant
coils. One coil (source coil) is coupled inductively to an
oscillating circuit; the other (device coil) is coupled
inductively to a resistive load. Self-resonant coils rely on the
interplay between distributed inductance and distributed
capacitance to achieve resonance.

7. 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 bulb.
The magnetic field can wrap around the
obstacle between power source and capture
coil.

8. electricity
Electro
magnetism
magnetism
Magnetic
basics
induction
Resonant
magnetic
coupling
8 resonance Energy
coupling

9. •Electricity is a general term that
encompasses a variety of
phenomena resulting from the
presence and flow of electric
charge.
•Magnetism is a force that acts at a
distance due to a magnetic field.
This field is caused by moving
electrically charged particles or is
inherent in magnetic objects such
as magnet.

10. •Electromagnetic induction is the
production of voltage across a
conductor moving through a
magnetic field.
•Electromagnetism is one of the
four fundamental interactions of
nature, along with strong
interaction, weak interaction and
gravitation. It is the force that
causes the interaction between
electrically charged particles; the
areas in which this happens are
called electromagnetic fields
•Energy/Power Coupling: Energy
coupling occurs when an energy
source has a means of
transferring energy to another
object

11. •Resonance :is the tendency of a
system to oscillate with larger
amplitude at some frequencies than
at others. These are known as the
system's resonant frequencies (or
resonance frequencies). At these
frequencies, even small periodic
driving forces can produce large
amplitude oscillations
•Resonant Magnetic Coupling:
Magnetic coupling occurs when two
objects exchange energy through
their varying or oscillating magnetic
fields. Resonant coupling occurs
when the natural frequencies of the
two objects are approximately the
same.

13. Types of wireless energy transfer
techniques are:-
Short range– Inductive
coupling
Mid range– Resonance
Inductive coupling
Long range-Electromagnetic
Wave Power Transfer

14. •Inductive Coupling is a method for
short range wireless energy
transfer.
•Inductive coupling works on the
principles of electro magnetic
induction.
• Its range can vary, but it’s often
very short.
Wireless electricity makes use
of the concept-
“Oscillating electric field
produces magnetic field and
oscillating magnetic field
produces electric field”.

15. Resonant Inductive
1 Coupling
Uses almost the same
concept as Inductive
coupling just that the coils
operate at resonant
frequency leading to
efficient transfer of energy
over a larger distance

16. LONG RANGE: FAR-FIELD POWER TRANSFER
 Far-field method achieves longer ranges which is
much greater than the diameter of device.
 These far-field type techniques include Radio &
Microwave Power Transmission Techniques &
LASER Techniques.

17. Block diagram for witricity mechanism

18. WITRICITY ENABLED ROOM

19. APPLICATIONS
CONSUMER ELECTRONICS
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.

20. Transportation
•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.
•Direct wireless power
interconnections to replace
costly vehicle wiring harnesses
and slip rings.

21. Other Applications
•Direct wireless power
interconnections and automatic
wireless charging for implantable
medical devices (ventricular assist
devices, pacemaker, defibrilator, etc).
•Automatic wireless charging and for
high tech military systems (battery
powered mobile devices, covert
sensors, unmanned mobile robots and
aircraft, etc).
•Direct wireless powering and
automatic wireless charging of smart
cards.
•Direct wireless powering and
automatic wireless charging of
consumer appliances, mobile robots,
etc.

22. WE CAN REDUCE Trillion Of Towers which are Around Us
Production of 40 Billion Disposable Batteries / Yr can be reduced
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23. WiTricity’s technology is a non-
radiative mode of energy transfer,
relying instead on the magnetic
near field. Magnetic fields interact
very weakly with biological
organisms—people and animals—
and are scientifically regarded to
be safe. WiTricity products are
being designed to comply with
applicable safety standards and
regulations.

24. ADVANTAGES
 No need of line of sight.
 No need of power cables and
batteries.
 Does not interfere with radio
waves.
Wastage of power is less.
Negative health
implications.
Highly efficient than
electromagnetic induction.
Less costly
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25.  Wireless power transmission can be possible
only in few meters.
 Efficiency is only about 40%.
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