“PIEZO CHARGER”

(A PORTABLE MOBILE CHARGER )

NAME:     KARTHIK MOTHIKI

YEAR:      FIRST YEAR

BRANCH: MECHATRONICS

PROBLEM STATEMENT:

Nowadays the mobile phone became a part and parcel of our life. It is not possible for us every time to find a charging port for our mobiles or power bank. Why don’t we think of a mobile (portable) charger where we could produce the electricity required by ourselves?

COMPONENTS REQUIRED:

Components                                                               No.ofcomponents

Piezo-electric crystals                                                              7-10

Diodes                                                                                     4

Resistors                                                                                  As Required

Capacitors                                                                               2

IN 7805                                                                                    1

LED                                                                                          1

Connecting Wires                                                                     As Required

Multimeter                                                                               1

Rechargeable Batteries (5000 mAH)                                        1

(Li-ion batteries)

CIRCUIT DIAGRAM :

:

Here

P1, P2, P3, P4 are Piezoelectric transducers

D1,D2,D3,D4 are Diodes

C is the capacitor and acts as Filer for getting DC Output

R is Resistor

IN 7805 is an IC which act as a voltage regulator

EXPLANATION:

The main ideology of this model is to produce electricity with our work. A Piezoelectric transducer could effectively do this.

PIEZOELECTRIC TRANSDUCER:

Piezoelectric Effect is the ability of certain materials to generate an electric charge in response to applied mechanical stress. The principle of operation of a piezoelectric sensor is that a physical dimension, transformed into a force, acts on two opposing faces of the sensing element. The detection of pressure variations in the form of sound is the most common sensor application.

If we want to reduce the number of piezoelectric substances in the given circuit we can use a voltage amplifier for increasing the output voltage. We can use Voltage Multiplier AD620 which gives 5V DC output signals.

Reference for voltage amplifier:

APPLICATIONS OF PIEZOELECTRIC TRANSDUCER:

Ø  High Voltage and Power Sources

Ø  Sensors

Ø  Piezoelectric Motors

Ø  Electronic Frequency Generation

Ø  Micro balances

Ø  Ultra Fine Focusing of Optical Assemblies

CALCULATIONS:

Voltage calculation:

P=e*eo*V/(kt*d33*t)

Ø  P=pressure output

Ø  e=relative dielectric,

Ø  eo=permittivity in vacuum

Ø  V= voltage applied

Ø  kt=coupling factor

Ø  d33=piezoelectric constant

Ø  t=thickness of the piezoelectric layer

D33:

Piezoelectric coefficient or Piezoelectric Modulus, d33, that means when you applied electric field, or the polarization on the application of stress: P is polarization and Dxy piezoelectric coefficients. Here x and y are the applied field direction and measurement direction.

 

Reference:

https://www.sciencedirect.com/topics/engineering/piezoelectric-voltage

 

Let us consider we are using one piezoelectric substance, an 80kg man when jumps exert 784.8N of force.

The same man produces nearly 1psi of pressure which is equal to 6894.76Pa.

By considering the lowest ratings of coefficients for the piezoelectric substance we will be getting output voltage as 0.93V.

Reference:

https://iopscience.iop.org/article/10.1088/1742-6596/662/1/012031/pdf

 

SOLUTION:

To achieve the solution for the problem statement we can design a shoe with 7-8 piezoelectric substances in the sole of the shoe. And an outlet for recharging the power bank or mobile.

We can print the circuit on PCB on a reduced scale which can be fitted in the shoe. Since we are putting the entire setup in the sole of the shoe the outlet for the

 

We can use this equipment while doing workouts, jogging, etc, we can produce High amounts of voltages which we can efficiently use in this way by charging our mobiles or power banks without searching for power sockets.

Application of the Project:

Ø  We can use these in the shoes of a veteran who can charge their required weapons with some modifications in the shoe’s style and according to their comforts.

Ø  Usage of piezoelectric substances in the night clubs, where people dance with a huge impact creating on the floor. By installing this piezoelectric setup beneath the floor could produce the voltage required to run the club.

Ø  We can put this under the speed breaker which comes before the Toll Plaza. Heavy vehicles come and go through that speed breaker which produces enough voltage for giving supply to the toll plaza.

Ø  A series of crystals can be laid below the floor mats, tiles, and carpets which are frequently used at public places.

Ø  The piezoelectric crystals can be laid down under the keys of a mobile unit and keyboards. With the press of every key, the vibrations created can be used for piezoelectric crystal and hence can be used for charging purposes.

References:

ü  https://iopscience.iop.org/article/10.1088/1742-6596/662/1/012031/pdf

ü  https://ae01.alicdn.com/kf/HTB1O.dJdq1s3KVjSZFAq6x_ZXXaH/AD620-Microvolt-MV-Voltage-Amplifier-Signal-Instrumentation-Module-Board.jpg

ü  https://PiezoelectricOutputEquations%20(3).pdf

ü  https://www.skyfilabs.com/project-ideas/latest-projects-based-on-Piezoelectric-material