2. INTRODUCTION
Cell Phones – Integral Part of Our Social Life
• Social Contacts
• Playing Games
• Watching Movies, Listening Music, etc.
• Banking
• Conferences
According to the Magazine `THE GUARDIAN’,
there are 4.1 billion users of Cell Phones in the
World, ie. 60 % of World Population.
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3. INTRODUCTION ...CONTD
`International Energy Agency’ says 1.4 billion
people around the world have no access to
Electricity.
Scarcity of Electricity affects a huge portion of
population in Cell Phones usage.
Natural calamities, like Earth Quakes, Tsunamis,
Landslides, etc. lead to power outages.
Daily One Unit Electricity required for Cell
Phone charging.
THERE IS AN URGE FOR
AN ALTERNATE ENERGY SOURCE.
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6. PIEZOELECTRICITY
Piezoelectricity was discovered by Curie Brothers
in 1880.
It is the generation of electric field from applied
pressure.
It is observed in crystalline materials.
The materials exhibiting the direct piezoelectric
also exhibit the reverse piezoelectric effect
(the internal generation of a mechanical strain
resulting from an applied electrical field.)
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8. PIEZOELECTRIC WORKING
Crystals generally have a charge balance
where negative and positive charges precisely
nullify each other
When this charge balance is disrupted by an
external force, such as, applying physical stress
to a crystal, the energy is transferred by
electric charge carriers
When pressure is applied, a negative charge is
produced on the expanded side and a positive
charge on the compressed side.
Once the pressure is relieved, electrical current
flows across the material.
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13. GYMS AND WORKPLACES
Vibrations caused from
machines in the gym.
At workplaces,
piezoelectric crystal are
laid in the chairs for
storing energy.
Utilizing the vibrations in
the vehicle like clutches,
gears etc.
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14. MOBILE KEYPADS & KEYBOARDS
Crystals laid down
under keys of mobile
unit and keyboard.
For every key pressed
vibrations are created.
These vibrations can be
used for charging
purposes.
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15. POWER GENERATING BOOTS OR SHOES
Idea was researched in
US.
To power the battlefield
equipment by generators
embedded in soldier
boots.
Idea was abandoned due
to the discomfort.
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16. FLOOR MATS & PEOPLE POWERED
DANCE CLUBS
Series of crystals can be laid below the floor mats, tiles and
carpets.
One footstep can only provide enough electrical current to
light two 60-watt bulbs for one second.
When mob uses the dance floor, an enormous voltage is
generated.
This energy is used to power the equipment of nightclubs.
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19. Low voltage Audio power amplifier
4V ac output with biasing voltage of 5V
Voltage gain 20-200
Applications: AM-FM radio amplifiers, TV sound
systems, Power converters etc.
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20. Quadrupler Circuit
DC output equal to
four times the peak
voltage value
(4Vp) of the
sinusoidal input
signal. Also, using
large value
capacitors will help
to reduce the ripple
voltage.
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21. RESULT & OBSERVATIONS
Output of voltage quadrupler circuit:11.2V
with 65mA from 118db sound.
Battery output:2.1V after 3min.
Within 20mins ,fully charged-3.68V.
Output power of quadrupler circuit:-
o .0757W before applying sound
o .7345W after applying sound source on
piezo disc.
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24. FUTURE IMPROVEMENT
Piezoelectric transducers suitably placed
inside and outside of cell phone casing.
Conversion circuit housed inside mobile
phone.
User talks over his mobile, sound from his
voice converts into electric power.
Increasing air or sound pressure mechanically-
using horn.
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26. APPLICATIONS
Military Purpose (war field, border and hilly regions).
When travelling in a long journey, during a trek or beach
when switch boards are not available.
While continuously talking on the phone with a low battery
especially in android and smart phones where battery gets
quickly discharged due to running applications.
In outdoors with various sources like train whistle in
railway station, noise in traffic, industries and public
places.
Sound produced from a running hydraulic pump and
construction piling.
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27. ADVANTAGES
Simple & Portable
Useful in areas where there is
no electric power at all.
Helpful during natural
disaster.
DISADVANTAGES
We do not get piezoelectric
transducer with high
conversion efficiency.
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28. CONCLUSION
An effective way of producing usable electric power from available sound
energy is presented.
Piezoelectric transducers can be used for conversion of sounds into electric
energy.
The produced electric energy is stored in super-capacitors which is then
summed up and amplified through adder and voltage multiplier circuits.
The resultant electric power can be used to charge a rechargeable mobile
battery.
If we will be able to convert sound energy to electric energy efficiently it
could help us to reduce the scarcity of electrical energy globally.
The noise pollution on roads and runways due to traffic could be converted
into electric energy and power the street lightning, signals and various
other electrical appliances.
With considerable research and sophistication to this technology, we can
expect a world with no external chargers for mobile phones in the future.
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29. REFERENCES
1. Tryhorn, Chris. The Guardian. Guardian News and Media, 02 Mar.
2009. Web. 02 Mar. 2012.
2. Seminar on “Energy poverty: The missing Millennium Development
Goal”, International. Energy Agency, March, 2012.
3. John Therampilly, Energy harvesting from multiple sources for
Battery charging. March 2012.
4. Robert John Littrell, “High Performance Piezoelectric MEMS
Microphones”, Dissertation of Doctor of Philosophy (Mechanical
Engineering), The University of Michigan, 2010.
5. Takeuchi M, Matsuzawa S, Tairaku K, Takatsu C. Piezoelectric
generator as power supply for RFID-tags and applications, Proc. IEEE
Ultrasonics Symposium, New York City, USA, pp. 2558–2561, 28–31
October 2007.
6. T. Dikshit, D. Shrivastava, A. Gorey, A. Gupta, P. Parandka, S. Katiyal,
“Energy Harvesting via Piezoelectricity” , proceedings of the 4th
National Conference; INDIACom-2010, 25 – 26 February, 2010.
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