Wireless power transmission involves transmitting electric power through the air without wires. In 1899, Nikola Tesla proposed a method of wireless power but achieved only 15% efficiency due to using radiative transmission. In 2007, MIT engineers developed a method using resonant induction that powered a 60W lightbulb from 7 feet away at 40% efficiency, demonstrating practical wireless power transfer. Wireless power works by powering a magnetic coil that transmits electromagnetic waves to a receiving coil which absorbs the energy and uses it to charge a device. While wireless power eliminates wires, its range is limited to a few meters and efficiency is around 40%.

1. PRESENTED BY
M.HEMADRI REKHA K.RAMYA
II B.TECH, EEE II B.TECH, EEE
1310431 1310427

2. WIRELESS POWER
 Transmission of energy through the air.
 Process of transferring electric energy or
power over distance without wires.
 Also known as “WiTricity” and “ Wirelss
Power Transmission”.
 Eliminates the use of cables for
transmission of power.

3. History of Wireless Power
 In 1899,Sir Nikola
Tesla proposed a
method of Wireless
Power Transmission.
 Tesla enlighten 200
lamps at the
distance of 40 km.
But only 15%
efficiency was
achieved.
 As it is in Radiative
mode , most of the
Power was wasted
and has less
efficiency.

4. The Forgotten Invention is
reborn in 2007
 A group of
engineers at MIT
came up with the
idea to use resonant
induction to transmit
power wirelessly.
 MIT powered 60
watt light bulb from 2
mts (7 ft) at 40%
efficiency.
 First practical
example of Witricity.

5. How Wireless Power Works?
 1.Magnetic coil is
housed in a box and
can be set in wall or
ceiling.
 2.Antenna A,
powered by mains
,resonates at a specific
frequency.
 3. Electromagnetic
waves transmitted
through the air.
 4. Second magnetic
coil (Antenna B) fitted
in laptop/TV etc
resonates at same
frequency as first coil
and absorbs energy.
 Energy charges the
device.

6. System Description

7. Working Principle
 One Simple Physics rule !
 At source : Electricity => Magnetic
Wave
 At Device : Magnetic Wave =>
Electricity

11.  Batteries can be
charged , it is just
enough to place
the device to top
of one of these
surfaces

12. WPT makes products:
More Convenient:
• no manual
recharging or
changing batteries.
• Eliminate unsightly ,
unwieldy and costly
power cords.
More Reliable
• never run out of
battery power.
• Reduces product
failure rates by fixing
the “weakest link”.

13. Advantages
 Safe ,fairly efficient ,good range.
 Getting rid of great deal of cables !
 More secure , no risk of getting
shocked.
 Placed where you cannot have
physically cable ,solution wiTricity
 No wires.
 Need for battery is eliminated.
 Ewaste is eliminated.

14. Disadvantages
 wireless power transmission can be
possible only in few meters.
 Efficiency is only about 40%.
 Need for standardization and
adaptation. So a little over heating
occurs because of different voltages.
 Refitting old equipment or purchasing
new equipment could become a very
expensive endeavor.
 Possibility of “energy theft”.

15. HOW SAFE IS WITRICITY
 Human beings or other objects placed
before the transmitter and receiver do
not hinder transmission of power.
 Magnetic fields tend to interact very
weakly with the biological tissues of
the body, and so are not prone to
cause any damage to any living
beings.

16. Conclusion
 Think that the city
will be covered with
WPT hotspots ,just
like wireless
internet there will
be no need of
charging batteries,
or carrying
adapters all
around.