Piezo-Electric Generator

AIM:

Electricity generation using piezo-electric material by footfall pressure

INTRODUCTION:

The increasing desire for completely self-powered electronics has caused the amount of research into power harvesting devices to become progressively larger over the last decade. With the advances being made in wireless technology and low power electronics, sensor are being developed that can be placed almost anywhere. However, because these sensors are wireless, they require their own power supply which in most cases is the conventional electrochemical battery. Once these finite power supplies are extinguished of their power, the sensor must be obtained and the battery replaced. The task of replacing the battery is tedious and can become very expensive when the sensor is placed in a remote location. These issues can be potentially alleviated through the use of power harvesting devices. The goal of a power harvesting device is to capture the normally lost energy surrounding a system and convert it into usable energy for the electrical device to consume. By utilizing these untapped energy sources electronics that do not depend on finite power supplies, such as the battery, can be developed. One source of typically lost energy is the ambient vibrations present around most machines and biological systems. This source of energy is ideal for the use of piezoelectric materials, which have the ability to convert mechanical strain energy into electrical energy and vice versa. As compact, low power electronics become more prevalent in everyday use and as their increasing portability requires reliable power sources, ambient energy harvesting devices show much potential over batteries. Indeed, by relying on energy scavenged from the environment, such electronics are no longer restricted by the periodic maintenance that batteries demand. In particular, energy harvested parasitically from human movements has garnered much discussion. Perhaps the most energy abundant and readily utilized form of ambient human power is walking. The project aims at developing a shoe embedded with piezoelectric material (PVDF) into a wearable energy supplier.

PIEZOELECTRIC CRYSTAL:

Piezoelectricity is the ability of some materials (notably crystals, certain ceramics, and biological matter such as bone, DNA and various proteins) to generate an electric field or electric potential in response to applied mechanical strain. The effect is closely related to a change of polarization density within the material's volume. If the material is not short-circuited, the applied stress/strain induces a voltage across the material. However, if the circuit is closed the energy will be quickly released. So in order to run an electric load (such as a light bulb) on a piezoelectric device, the applied mechanical stress must oscillate back and forth. For example, if you had such a device in your shoes you could charge your cell phone while walking but not while standing.

PIEZO ELECTRIC MATERIALS: The materials which convert mechanical energy to electrical energy are called piezo electric materials. Examples: Quartz, Rochelle salt, cane sugar, etc.

PIEZO ELECTRIC EFFECT: This effect was first demonstrated by Pierre curie and Jacques curie. According to this effect due to the pressure the electricity is produced. When pressure is applied on piezoelectric material then mechanical energy is converted into electrical energy. This production of electrical energy is called as piezo electric effect.

PIEZO ELECTRICITY: The electricity produced due to the piezo electric effect is called as piezo electricity.

FOOTFALL PRESSURE: The pressure produced by the footfall on the ground is called is footfall pressure.

MECHANISM:

The nature of the piezoelectric effect is closely related to the occurrence of electric dipole moments in solids. The latter may either be induced for ions on crystal lattice sites with asymmetric charge surroundings (as in BaTiO₃ and PZTs) or may directly be carried by molecular groups. The dipole density or polarization may easily be calculated for crystals by summing up the dipole moments per volume of the crystallographic unit cell. As every dipole is a vector, the dipole density P is also a vector or a directed quantity. Dipoles near each other tend to be aligned in regions called Weiss domains. The domains are usually randomly oriented, but can be aligned during poling, a process by which a strong electric field is applied across the material, usually at elevated temperatures.

Of decisive importance for the piezoelectric effect is the change of polarization P when applying a mechanical stress. This might either be caused by a re-configuration of the dipole-inducing surrounding or by re-orientation of molecular dipole moments under the influence of the external stress. Piezoelectricity may then manifest in a variation of the polarization strength, its direction or both, with the details depending on

1. The orientation of  P within the crystal.

2. Crystal symmetry.

3. The applied mechanical stress.

Working Methodology:

For energy generation through piezoelectricity piezoelectric crystals made of PZT are arranged in a grid on the floor the unique piezoelectric and converse piezoelectric properties of crystalline PZT allow us to design an electro-mechanical device. By operating the device at its mechanical resonance frequency, we can get a useful electrical output out of it. The active element is the heart of the transducer as it converts the stress due to weight to electricity. The active element is basically a piece of polarized material (i.e. some parts of the molecule are positively charged, while other parts of the molecule are negatively charged) with electrodes attached to two of opposite faces. As the major aim of making the Electricity generating floor is to utilize the stress from to human foot fall and generate electricity the mechanical stress due to human weight is considered as the input power and the electricity generated through it is the output.

To create electricity, the EGF will compress up to 1mm when being stepped on. Because of the air gap and one free end of the piezo crystal it will be able to vibrate freely when stress is released. As a result efficient power generation occurs. This small compression is enough to activate the internal generator of that module producing up to 5 -7 Watts of sustained output per module. This system allows for the floor to be set up in a huge range of possible sizes, shapes and designs.

Circuit System Requirements:

·        PCB board

·        LED lights

·        Multimeter

·        Piezo-eletric transducer

·        Connecting wires

·        Switch

·        500 μf capacitor

·        100 ohm resistor

·        Soldering kit

Circuit Working:

To a piezo electric sensor a diode is connected in series to allow the flow of current in only in one direction. To this 1KΩ resistor is connected .to this a capacitor of 500µf is connected in parallel so as to store current that is generated from piezo electric sensor .the whole system is now connected to LED lights .a switch is connected to the circuit to control the flow of current. When the pressure or stress is applied to the piezo electric sensor, current is passed through the diode and some amount of charge is stored in the capacitor for further uses .actually connecting a capacitor in parallel gives us more current than connecting it in series. To measure the current in the circuit a multimeter is connected and the values are recorded and a LED light is connected to the circuit so that it glows as the currents passes through it.

APPLICATIONS:

This electricity generating floor can be installed in the places where there will be a lot floating of population.

1.     Railway stations: These will be always busy with passengers. (Fig 1)

2.     Dance clubs: This is the most important place because there will be a lot of pressure is produced. This current produced is used for sound systems.

3.     Foot wears soles equipped with piezoelectric pads. (Fig 2)

4.     Gym machinery: On the gym machinery like thread wheels these can be arranged to produce current which can be used in music system.

5.     Footpaths: As all the pedestrians are compulsory to walk on the footpaths this will be more use full.

6.     Roads: As heavy vehicles move more pressure is applied on piezoelectric material and this can produce large amount of current which can be used for traffic display boards

7.     Shopping mall: There will be a lot of customers always visiting.

8.     Railway stations: These will be always busy with passengers.

by
N.Nikhil
M.Gopi Reddy
P.Mahati Aditya

Jumbled Words

#include<stdio.h>
#include<string.h>
int main()
{
FILE *f=fopen("words.txt","r");
int i=0,len,temp,j;
char c;
char word[15];
char shuffil_word[15],guessword[15];
start:
printf("WELCOME TO JUMBLED WORDS");
  printf("Guess the correct word\n");
     
  for (i=0;!feof(f);i++)
       {
        if((c=getc(f))==' ')
        break;
        else
        shuffil_word[i]=word[i]=c;
  }
  len=i;

for(i = 0; i < len; i++)
    {
        j = (rand()%len);
        temp = shuffil_word[i];
        shuffil_word[i] = shuffil_word[j];
        shuffil_word[j] = temp;
    }
    printf("\n");
    for(i=0; i<len; i++)
    {
          printf("%c", shuffil_word[i]);
    }
printf("\n\n");
again:
printf("Enter your guess...\n");
gets(guessword);
int guesslen = strlen(guessword);

if(guesslen!=len)
{
printf("\nThe Length of Guessed word and Actual Word is Mismatched\nTry Again...\n\n");
goto again;
}
for(i=0;i<len;i++){
if(guessword[i]!=word[i]){
printf("\nYou lost.");
goto gameloop;
}
}
printf("\nCongratulations! You Won the Game...!!!\n\n");
gameloop:
printf("\nDo you want to play again? (y/n)\n\n");
if(getch()=='y'||getch()=='Y')
goto start;
else
return;
}



NOTE: you need to create a text document with name of words and put program and text document in same folder
you need to enter the words in text document and program takes words from that document and jumbles it.

by

Kalyan Kurasala

TIC TAC TOE

#include<stdio.h>

#include<conio.h>

int main (void)

{

            int player = 0;

            int winner = 0;

            int choice = 0;

            int row = 0;

            int column = 0;

            int line = 0;

            int i;

            char k;

            jump: char board [3][3] = {

                                                                 {'1','2','3'},

                                                                 {'4','5','6'},

                                                                 {'7','8','9'}

                                                               };

            clrscr();

            for (i = 0; i<9 && winner==0; i++)

            {

                        printf("\n\n");

                        printf(" %c | %c | %c\n", board[0][0], board[0][1], board[0][2]);

                        printf("---|---|---\n");

                        printf(" %c | %c | %c\n", board[1][0], board[1][1], board[1][2]);

                        printf("---|---|---\n");

                        printf(" %c | %c | %c\n", board[2][0], board[2][1], board[2][2]);

                        player = i%2 + 1;

                        do

                        {

                                    printf("\nPlayer %d, please enter the number of the square "

                                                "where you want to place your %c: ",

                                                player,(player==1)?'X':'O');

                                    scanf("%d", &choice);

                                    row = --choice/3;

                                    column = choice%3;

                        }while(choice<0 || choice>9 || board [row][column]>'9');

                        board[row][column] = (player == 1) ? 'X' : 'O';

                        if((board[0][0]==board[1][1] && board[0][0]==board[2][2]) ||

                           (board[0][2]==board[1][1] && board[0][2]==board[2][0]))

                           winner = player;

                        else

                                    for(line = 0; line <=2; line++)

                                                if((board[line][0]==board[line][1] && board[line][0]==board[line][2])||

                                                            (board[0][line]==board[1][line] && board[0][line]==board[2][line]))

                                                            winner = player;

            }

                        printf("\n\n");

                        printf(" %c | %c | %c\n", board[0][0], board[0][1], board[0][2]);

                        printf("---|---|---\n");

                        printf(" %c | %c | %c\n", board[1][0], board[1][1], board[1][2]);

                        printf("---|---|---\n");

                        printf(" %c | %c | %c\n", board[2][0], board[2][1], board[2][2]);

            if(winner==0)

                                    printf("The game is a draw\n");

                        else

                                    printf("Player %d has won\n", winner);

            printf("Do you want to play another game(Y/N)");

            scanf("%c",&k);

            if(k=='y'||k=='Y')

                 go to jump;

            clrscr();

            return 0;

}

Guess the Number

#include<stdio.h>
#include<conio.h>
#include<stdlib.h>
int main()
{
int random;
int userguess;
int noofguess=0;
int k;
int i;

printf("\t\tThis is simple guessing game\n");
printf("\t\tI am thinking numberin between 1 and 100\n");
printf("\t\tYou have to guess correct number\n");
printf("\t\tHere are some hints for you\n");
printf("\t\tYour game starts now\n");
printf("\t\tHAPPY GUESSING\n");
random=rand()%100+1;
{

  int i;
   printf("->Factors are: \n");
  for(i=1;i<=random;i++)
  {
      if(random%i==0)
         printf("%d \n",i);
  }
{
int count=0,i;
for(i=1;i<random-i;i++)
{
if(random%i==0)
count++;
}
if(count==2)
printf("->It is Prime number\n");
else
printf("->It is Composite number\n");
}
{
if(random%2==0)
printf("->it is even number\n");
else
printf("->it is odd nnumber\n");
}
{
int temp,reverse=10;
temp=random;
while(temp!=0)
{
reverse=reverse*10;
reverse=reverse+temp%10;
temp=temp/10;
}
if(random==reverse)
printf("->It is palindrome\n");
else
printf("->It is not a palindrome\n");
}
do
{
printf("*enter number in between 1 to 100*\n");
scanf("%d",&userguess);
noofguess++;
if(userguess>random)
printf("%d is greater than what I am thinking\n",userguess);
if(userguess<random)
printf("%d is less than what I am thinking\n",userguess);
}
while(random!=userguess);
printf("congrats you have guessed the no.\n");
printf("total guesses = %d ",noofguess);

 

getch();
return 0;
}
}