This ppt explains the working of Tesla coil for wireless transmission of power and basics required to be covered for clear understanding.

1. EEE-IV

2. OVERVIEW
 INTRODUCTION
 DEFINITION
 HISTORY
 BASICS OF WITRICITY
 SOLID STATE TESLA COILS
 PRINCIPLE
 COMPONENTS
 WORKING
 PROS AND CONS
 APPLICATIONS
 CONCLUSION

3. INTRODUCTION
 In this era of modernization, electricity has become the unavoidable
part of life.
 The major source of conventional form of electricity is through
wires.
 One of the major issue in power system is losses occuring during
the transmission and distribution of electrical power.
 The percentage of loss of power during transmission and
distribution is approximated as 26%.
 The main reason for power loss during transmission and distribution
is resistance of wires used in grid.
 According to world resource institute(WRI),India‘s electricity grid
has the highest transmission and distribution losses in the world –a
whopping 27-40%.
 Tesla has proposed methods of transmission of electricity using
electromagnetic induction.

4. DEFINITION
 As the word wireless means “WITHOUT WIRE”.
 Wireless energy transfer or wireless power is the
transmission electrical energy from a power source to
an electric load without interconnecting man made
conductors.
 Wireless transmission is useful in cases where
interconnecting wires are inconvenient, hazardous or
impossible.
 WiTricity ensures that the cell phones, laptops, iPods
and other power hungry devices get charged on their
own, eliminating the need of plugging them in.
 Because of Witricity these devices won’t require
batteries to operate.

6. HISTORY
 Sir Nicolai Tesla was the first one to propose and research the idea
of wireless transmission in 1899, since then many scholars and
scientists have been working to make his dream a reality
 : Tesla continues wireless power transmission research in
Colorado springs and writes “The inferiority of the induction method
would appear immense as compared with the disturbed charge of
ground and air method”.
 1961: William C. Brown publishes an article exploring possibilities
of microwave power transmission
 2009: Sony shows a wireless electrodynamics- induction powered
TV set, 60 watts over 50 cm.

7. .
 Experiments performed between 1888 and 1907 by Nicolai Tesla
 Started efforts on wireless transmission by 1891 in experimental station
at Colorado.
 He lightened a small incandescent lamp by means of Resonant circuit
grounded on one end.
 In 1901, Tesla began construction of a large high voltage wireless power
transmission now called the Wardenclyffe tower at Shoreham, New
York.
 The idea of Tesla is taken research after 100 years by a team led by
Marine Soljacic from MIT.
 He used to lamp 200 lights from 40 km distance.

8. Basics of Witricity

9. FUNDAMENTALS
 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.
 Energy/Power Coupling
Energy coupling occurs when
an energy source has a means
of transferring energy to
another object.

11.  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.

12.  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. SOLID STATE TESLA COILS
 A tesla coil is basically high voltage
transformer that generates high
voltage electric sparks into the air.
 A Tesla Coil works much in the same
way your cell phone charger works,
but in reverse. Instead of reducing
voltage, it increases it.
 But a Tesla Coil does much more than
increase in voltage, it increases
frequency.
 Tesla designed it this way because
once we create very high voltage
electricity at a very high frequency, we
can create a field of energy with which
there is transmission of power.

14. Principle
 Wireless Electricity uses the principle which involves the
usage of inductively coupled objects with same
resonant frequency.
 The principle Electromagnetic Induction states that a
coil generating magnetic field induces a current in
another coil as it is being placed in the field of the
former coil.
 First, we employ a pre-made high voltage iron core
transformer to go from 120 V wall current to roughly
10,000V.
 The wire with 10,000 volts is wrapped into one very
large (primary) coil with only a handful of turns. The
secondary coil contains thousands of turns of thin wire.
This steps up the voltage to between 100,000 and one
million volts. This potential is so strong that the iron core
of a normal transformer cannot contain it. Instead, there
is only air between the coils.

15. Components
 1) Inductors:
The Tesla coil's primary and secondary coils are both inductors in
electrical terms. When the current flowing through an inductor
changes, it will create an opposing or reverse voltage.
 2) Spark Gaps:
A sparking plug in a car is a basic spark gap, its break-down
voltage dependent on the electrode gap size. Once it conducts, hot
ionized air in the gap gives it the ability to carry on, so long as a
current is flowing.
 3) Capacitor:
A good analogy for a capacitor is to think of it as a sponge, placed
on spilt water and left to slowly soak it up. If left for a minute and
then given a quick, hard squeeze, one minute's worth of soaking-
up is instantly released in a fraction of a second. In a Tesla coil
circuit this so called 'soaking-up' stage lasts only a few
milliseconds, while the 'squeezing-out' can be a thousand times
quicker in a few micro (millionths) of a second.

16. Components
 Resonant Circuit :
If a capacitor is placed across an inductor and voltage
applied, you will have a resonant circuit. As the capacitor
discharges, it sends current into the inductor that stores
this as energy in its magnetic field. But as the capacitor
discharges, the current into the inductor also diminishes.
This causes its magnetic field to collapse and generate an
opposing voltage back into the capacitor, allowing the cycle
to start all over again. The number of times that this 'back
and forwards' cycle happens per second, is the circuit's
resonant frequency, expressed in Hertz (Hz).


17. Working
 The circuit of the coil contains
a capacitor and a small hole
called a spark gap.
 When the coil is turned on,
electricity flows through the
circuit and fills the capacitor
with electrons, like a battery.
This charge creates its own
electric potential in the
circuit, which tries to bridge
across the spark gap.
 The capacitor ('C') is charged
up by a high voltage source,
like example of the sponge
soaking up water.

18. Working
 Once the capacitor attains a high
enough voltage the spark gap fires and
conducts (Fig 2 ). The spark gap is now a
short-circuit that completes the resonant
circuit (shown in red) of the primary
inductor and capacitor.
 The spark gap firing is virtually an
instantaneous discharge of the capacitor
energy into the inductor.
 The inductor (the primary) stores this
energy in its magnetic field with its lines
of force cutting into the secondary coil
(another inductor) and induces a voltage
into it. Once the capacitor is empty, the
current flow into the inductor stops, and
its magnetic field collapses causing a
reverse current (now fairly reduced) to
flow back into the capacitor again.

19. Working
 This means that the secondary coil
(an inductor) along with the
capacitance of the toroid also forms a
resonant circuit, behaving much like
the primary circuit. The secondary's
energy is therefore also resonating
back and forth between the coil and
the toroid. However it does not
dampen down the same as the
primary does, in fact it is steadily
increasing.
 In a perfect Tesla coil once breakout
has occurred this would be the end of
the matter, allowing a fresh charging
cycle to start all over again. What
usually occurs though is that as the
secondary's field starts collapsing it
starts to transfer its energy back
into the primary again.

20. Pros and cons
 PROS
 Allows a wide range of firing
rates to be investigated with a
variable speed rotary spark
gap, without encountering
beating and surging.
 Allows power throughput to
be controlled by altering the
rotary speed.
 Charging is slow immediately
after the spark gap fires.
 Provides excellent load
sharing if a 3 phase rectifier is
used at higher powers.
 CONS
 More complex circuit is
required.
 Greater cost.
 Large DC smoothing
capacitor is needed unless 3-
phase power is used. Such a
capacitor is expensive, and
stores lethal energy.
 High voltage, high inductance
charging inductor is needed.
This is a specialised part and
may be difficult to obtain.
 Requires a 3-phase supply to
be most effective.

21. Applications
 Tesla coil circuits were used commercially in spark gap
radio transmitters for wireless telegraphy telegraphy
until the 1920s,and in electrotherapy and
pseudomedical devices such as violet ray.
 Today, although small Tesla coils are used as leak
detectors in scientific high vacuum systems and
igniters in arc welders, their main use is entertainment
and educational displays.
 Tesla coils are built by many high-voltage enthusiasts,
research institutions, science museums, and
independent experimenters.
 Although electronic circuit controllers have been
developed, Tesla's original spark gap design is less
expensive and has proven extremely reliable.

22. TESLA COILS IN
ENTERTAINMENT Tesla coils can also be used to generate
sounds, including music, by modulating the
system's effective "break rate" (i.e., the rate
and duration of high power RF bursts)
 Tesla coils are very popular devices among
certain electrical engineers and electronics
enthusiasts. Builders of Tesla coils as a hobby
are called “Coilers". A very large Tesla coil,
designed and built by Syd Klinge, is shown
every year at the Coachella Valley Music and
Arts Festival, in Coachella, Indio, California,
USA.
 People attend "coiling" conventions where
they display their home-made Tesla coils and
other electrical devices of interest.

23. CONCLUSION
 The main objective was to demonstrate wireless
power transmission using solid state tesla coils.
 Tesla coils are remarkable devices able to
generate high voltage, high frequency
waveforms with little control circuitry.
 Most of the builders of Tesla coils are
interested in producing electric arcs and visible
effects suitable for displays and general
amusement, not in producing power supplies and
power effects units which may have significant
practical importance.
 It has demonstrated that tesla coils can be
designed for wireless power transmission.

24. REFERENCES
 Basharat Nizam, “Inductive Charging Technique,”
International Journal of Engineering Trends and
Technology (IJETT), Volume4, Issue4- April 2013
 A.K. RamRakhyani, S. Mirabbasi, and M. Chiao,
“Design and Optimization of Resonance Based
Efficient Wireless Power Delivery Systems for
Biomedical Implants,” IEEE Transactions on,
Volume5, No1:48–63,February 2011.
 David W Baarman, “Understanding wireless
power”, Director of Advanced Technologies,
Fulton Innovation Joshua Schwannecke,
Research Scientist, Fulton Innovation December
2009
 Shawon Senjuti, “Design and optimization of
efficient wireless power transfer links for
implantable biotelemetry systems,” A thesis
submitted in partial fulfillment of the requirements
for the degree of Master of Engineering Science
 Dr. Morris Kesler, “Highly resonant wireless power
transfer”.

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