Wireless electricity or WiTricity is the transfer of electric energy or power over a distance without the use of wires. In order for the energy to be transferred safely coupled resonators are used. Coupled resonators are two objects of the same resonant frequency that exchange energy efficiently without much leakage. Minimizing energy leakage is very important because the goal is to have as much energy as possible be transferred from one object to another.

1. TECHNO INDIA COLLEGE OF TECHNOLOGY
SEMINAR ON
WiTricity – Future of Electricity
BY
SHAHBAAZ AFRIDI
ECE 3rd YEAR
ROLL No. : 18700313061
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3. POINTS OF DISCUSSION…
What is WiTricity ?
Need of WiTricity
History of Wireless Power
Working Principle of WiTricity
Application in various Fields
Is WiTricity safe ?
Merits and Demerits
Conclusion
Bibliography 3

4. What do you mean by WiTricity ???
WiTricity is nothing but Wireless Electricity.
The term WiTricity is derived from the combination of
two words wireless + electricity = WiTricity.
The term WiTricity is defined as the ability to
provide electrical energy to remote objects without
wires using oscillating magnetic fields.
Currently, wired electricity powers nearly everything. It
travels through wires in the form of Alternating Current
electricity, and powers most of our devices.
Wireless transmission of energy will remove our
dependency on wires.
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5. Need of WiTricity :
Due to the Rapid development of autonomous electronics like Laptops, Cell-
phones, House-hold robots and all those devices typically rely on chemical energy
storage (i.e.) Chargeable Battery which in turn demand for electricity .
Why not Wires ?
Most of the Electrical energy is wasted during transmission.
On an average energy loss is 30% globally, but in India it exceeds by 40%.
 Why not Batteries?
Estimated that 40 billion batteries per year add to the e-waste burden ,and
ofcourse its not a good sign.
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6. History of Wireless Power :
In 1890, Sir Nikola Tesla Proposed a method of
Wireless Power Transmission.
In 1899, he was able to light 200 lamps over 25
miles away without using wires.
 As it is in Radiative mode, most of the Power was
wasted and has less efficiency.
In 2005, Dave Gerding coined the term WiTricity
which is being used today.
The efficient midrange power transfer concept is
WiTricity. In this model source and load are in
Magnetic resonance so there is no power loss. 6

7. The forgotten invention is reborn in 2007
The idea of wireless electricity has been around since the
early days of tesla coil.
But thanks to the group of MIT scientists, “WiTricity” (as
they call it) is now one step closer to practical reality.
In 2007, six MIT members headed by Marin Soljacic were
able to successfully transmit power to a 60W bulb within a
distance of 2m at a frequency of 9.9 MHz.
They used the concepts of non radiative mid range energy
transfer, resonance and inductive coupling.
Efficiency at that point was just approximately 43%.
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8. WiTricity Technology
1. Power source is connected to AC power.
2. Bulb is connected to capture device.
3. Blue lines represent the magnetic near
field induced by the power source.
4. Yellow lines represent the flow of energy
from the source to the capture coil.
5. This power lights up the bulb.
6. The magnetic fields can wrap around the
obstacle between power source and
capture coil.
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9. Working principle of WiTricity
The basic principle involved
in WiTricity concept is, two
object should have same
resonating frequency.
 Both should be in
Magnetic resonance at
Strongly coupled regime.
 Then they tends to
exchange energy , while
dissipating relatively little
energy to the extraneous
off-resonant objects.
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10. Block Diagram Representation
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11. SOME BASIC COMPONENTS AND
CIRCUITS FROM THE BLOCK DIAGRAM
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Amplifier
Full Wave Rectifier

12. Creative Visualization
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13. How WiTricity works ???
1) Power from mains to antenna, which is made of copper.
2) Antenna resonates at a frequency of 10MHz, emitting electromagnetic waves.
3) “Tails” of energy from antenna “tunnel” up to 2.5m (8.2 ft).
4) Electricity picked up by laptop’s antenna, which must also be resonating at 10MHz.
Energy used to re-charge device.
5) Energy not transferred to laptop is re-absorbed by source antenna. People /other
objects will not be affected as they are not resonating at 10MHz.
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14. Energy Transfer Techniques
There are three types of energy transfer techniques depending upon the range
of wireless transmission.
1) Short Range - Inductive Coupling
2) Medium Range – Resonance Inductive Coupling.
3) Long Range – Electromagnetic Wave Power Transfer.
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15. Applications of WiTricity
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17. Is WiTricity Technology Safe ???
WiTricity Technology is a non radiative mode of energy transfer.
Magnetic Fields interact very weakly with biological organisms –people and
animal, and are scientifically regarded as safe.
WiTricity protects are designed to comply with safety standards and regulations.
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18. ADVANTAGES
Safe, fairly efficient, good range.
Magnetic fields interact weakly with biological
masses.
No need of power cables and costly batteries.
Efficiency can be increased.
Boon for devices which uses midrange power.
One stationary coil in a room could power
multiple devices with receiving coils.
 Significant decrease in the number of people
being electrocuted in an accident.
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19. LIMITATIONS
Wireless power transmission is only
possible in few meters.
Little over heating occurs because of
different voltages.
Possibility of Energy Theft.
Efficiency decreases with distance.
Resonance condition should be satisfied
and if any error exists , there is no
possibility of power transfer.
Refitting old equipment or purchasing
new one could become very expensive.
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20. CONCLUSION
The transmission of power without wires is not only theory or a mere
possibility, it is now a reality. The electrical energy can be economically
transmitted without wires to any terrestrial distance.
 This system would reduce the cost of electrical energy used by the consumer
and get rid of the landscape of wires, cables, and transmission towers. It has
negligible demerits like reactive power which was found insignificant
and biologically compatible.
WiTricity Corp. is working towards miniaturizing and packaging the
technology so that it can be built directly into a wide variety of products and
system
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21. Future of WiTricity
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22. REFERENCES
Book
Wireless Power Transfer via Radiowaves by
Naoki Shinohara, Wiley publication ,9th
revised edition ,page 256 -263.
Internet
http://en.wikipedia.org/wiki/WiTricity
http://www.electricitybid.com/electricity/ind
ex.php/2007/06/08/witricity
http://www.witricity.com
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24. -By Shahbaaz Afridi
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