secrets of wireless electricity

8/10/2019 Secrets of Wireless Electricity

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Witricity

Wireless electricity


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Wireless transmission of energy using:

Electromagnetic radiation, like

radio waves

Directed electromagnetic

radiation, like lasers

Inductive coupling, like

transformers

Each of these has its own

inherent drawbacks


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Resonant inductive coupling

Resonance", a phenomenon that causes an object to vibrate

when energy of a certain frequency is applied.

Resonance is the tendency of a system to oscillate at its

maximum amplitude, associated with specific frequencies

known as the system's resonance frequencies(or resonantfrequencies).

Two resonant objects of the same frequency they tend to

couple very strongly.

Energy can tunnel from one object to another when theyresonate at the same frequencies.


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Tesla coil

A Tesla coil is a type of resonant transformercircuit invented by Serbian-Americanscientist Nicola Tesla around 1891.

It is usually used to generate very highvoltage, low current, high frequencyalternating current electricity.

A Tesla coil consists of two, or sometimes

three, coupled resonant electric circuits, butis difficult to define precisely, as Teslaexperimented with a large variety of coils andconfigurations.


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Circuit


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Near and far fields

The near field and far field of an antenna or other

isolated source of electromagnetic radiation are

regions around the source where different parts of

the field are relatively more or less important.

The boundary between the two regions is only

vaguely defined, and depends on the dominant

wavelength () emitted by the source.

Roughly speaking, the near field is the region within

a radius, r.


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The key researcherMarin Soljacic

Marin Soljacic was the

leader of the team ofresearches from MIT

who had found out a

means of transmitting

electricity to electricalgadgets without using

any wires.


8/18TransmitterReceiver

First experiment


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First experiment

This experiment was done using two

copper coils of diameter two feet, a

transmitter that was attached to a

power source and a receiver that was

placed about seven feet from the

transmitter.

This receiver was attached to a light

bulb and once power was switched on

at the transmitter, the bulb lit up

despite there being no physical

connection between the transmitterand receiver.


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A capacitor stores energy in the

electric field between its plates,

depending on the voltage across it,

An inductor stores energy in its

magnetic field, depending on the

current through it

A simple LC circuit:


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The conceptCurved coil of wire as an inductor

Acapacitance plate, which can hold a charge,

attaches to each end of the coil.


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1) Power from mains to antenna, which is made of copper

2) Antenna resonates at a frequency of 6.4MHz, emitting

electromagnetic waves

3) 'Tails' of energy from antenna 'tunnel' up to 5m (16.4ft)

4) Electricity picked up by laptop's antenna, which must also be

resonating at 6.4MHz. Energy used to re-charge device

5) Energy not transferred to laptop re-absorbed by source

antenna. People/other objects not affected as not resonating

at 6.4MHz


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Merits

Power lost to surroundings is comparativelyless

Relatively safe

No need to have an uninterrupted line of sight

And finally the most important of them all,

No wires!!


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Demerits

A debatable issue whether its safe living in a

house with low power witricity network.


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Need for w ireless power transm ission

Electrical power accounts for much of the energy consumed.

Much of this power is wasted during transmission from power

plant generators to the consumer.

Present system of electrical distribution is only 70-74% efficient.

This method would eliminate the need for an inefficient, costly,and capital intensive grid of cables, towers, and substations.

Calculated to be 90-94% efficient.

Reduce the cost of electrical energy

The tangle of cables and plugs needed to recharge today's

electronic gadgets is very hectic for a home which is not wellorganized.


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Automaticrecharge!

The most important

application


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Witricity, the power to

cut the cord

Any questions???

secrets of wireless electricity

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