Footstep power generation

Foot step power generation system for rural energy
application to run AC and DC loads

Technical Specifications:
Title of the project : Foot step power generation system for rural energy
Application to run AC and DC loads
Domain : Renewable Energy Management, Energy System
Power Supply : +5V, 500mA Regulated Power Supply and 12V lead acid
Battery
Source : Piezo electric transducers array
Inverter : 1
Applications : Metros, Rural Applications etc.,
Developed By : M/S Wine Yard Technologies
Phone : 040- 6464 6363,
Web site : www.WineYardProjects.com

INDEX
1. TECHNICAL SPECIFICATION
2. ABSTRACT
3. BLOCK DIAGRAM
4. INTRODUCTION OF THE PROJECT
5. INTRODUCTION OF SENSORS
6. PIEZO ELECTRIC SENSOR
7. LEAD AICD BATTERY
8. LIGHT EMITTING DIODE
9. HARDWARE EXPLANATION
10. UNIDIRECTIONAL CURRENT CONTROLLER
11. INVERTER
12. BULB
13. WORKING PROCEDURE
14. ADVANTAGES
15. APPLICATIONS
16. CONCLUSION
17. REFERENCES

Man has needed and used energy at an increasing rate for his sustenance and well-
being ever since he came on the earth a few million years ago. Due to this a lot of energy
resources have been exhausted and wasted. Proposal for the utilization of waste energy of foot
power with human locomotion is very much relevant and important for highly populated
countries like India and China where the roads, railway stations, bus stands, temples, etc. are all
over crowded and millions of people move around the clock. This whole human/ bio-energy
being wasted if it can be made possible for utilization it will be great invention and crowd energy
farms will be very useful energy sources in crowded countries
In this project we are generating electrical power as non-conventional method by simply walking
or running on the foot step. Non-conventional energy system is very essential at this time to our nation.
Non-conventional energy using foot step is converting mechanical energy into the electrical energy. This
project uses piezoelectric sensor.
In this project the conversion of the force energy in to electrical energy. The control mechanism
carries the piezo electric sensor, A.C ripples neutralizer, unidirectional current controller and 12V,
1.3Amp lead acid dc rechargeable battery and an inverter is used to drive AC/DC loads. The battery is
connected to the inverter. This inverter is used to convert the 12 Volt D.C to the 230 Volt A.C.
This 230 Volt A.C voltage is used to activate the loads. We are using conventional battery
charging unit also for giving supply to the circuitry.
This project uses regulated 5V, 500mA power supply. 7805 three terminal voltage
regulator is used for voltage regulation. Bridge type full wave rectifier is used to rectify the ac
out put of secondary of 230/12V step down transformer.

Rechargeable
Battery
Block Diagram
Block Diagram:
Piezo electric
transducers
array
AC ripple
neutralizer
Unidirectional
Current Controller
Conventional Battery Charger Unit
Step
down
T/F
Bridge
Rectifier
Filter
Circuit
Regulator
Unidirectional
Current
Controller
Block Diagram: Foot step power generation system for rural energy application to run AC and DC loadsInverter
ON/ OFF
control
switch
AC 230V
Load
Protector sheet made from
soft core material

INTRODUCTION TO PROJECTINTRODUCTION TO PROJECT
Man has needed and used energy at an increasing rate for his sustenance and
well-being ever since he came on the earth a few million years ago. Due to this a lot of energy
resources have been exhausted and wasted. Proposal for the utilization of waste energy of foot
power with human locomotion is very much relevant and important for highly populated
countries like India and China where the roads, railway stations, bus stands, temples, etc. are all
over crowded and millions of people move around the clock. This whole human/ bio-energy
being wasted if it can be made possible for utilization it will be great invention and crowd energy
farms will be very useful energy sources in crowded countries
Walking is the most common activity in day to day life. When a person
walks, he loses energy to the road surface in the form of impact, vibration, sound etc, due to the

transfer of his weight on to the road surface, through foot falls on the ground during every step.
This energy can be tapped and converted in the usable form such as in electrical form.
In this project the main role is played by piezoelectric sensor. These sensors
convert the mechanical energy into electrical energy. This energy is stored in rechargeable
battery and this energy is used for operating A.C and D.C.
INTRODUCTION TO SENSOR

What is sensor?
Sensors are sophisticated devices that are frequently used to detect and respond to electrical or
optical signals. A Sensor converts the physical parameter (for example: temperature, blood
pressure, humidity, speed, etc.) into a signal which can be measured electrically. Let’s explain
the example of temperature. The mercury in the glass thermometer expands and contracts the
liquid to convert the measured temperature which can be read by a viewer on the calibrated glass
tube.

Criteria to choose a Sensor
There are certain features which have to be considered when we choose a sensor. They are as
given below:
1. Accuracy
2. Environmental condition - usually has limits for temperature/ humidity
3. Range - Measurement limit of sensor
4. Calibration - Essential for most of the measuring devices as the readings changes with time
5. Resolution - Smallest increment detected by the sensor
6. Cost
7. Repeatability - The reading that varies is repeatedly measured under the same environment
Definition:
A sensor is a device that measures a physical quantity and converts it into a signal which can be
read by an observer or by an instrument. For example, a mercury-in-glass thermometer converts
the measured temperature into expansion and contraction of a liquid which can be read on a
calibrated glass tube. A thermocouple converts temperature to an output voltage which can be
read by a voltmeter. For accuracy, all sensors need to be calibrated against known standards
(OR)
Sensor is the device which converts any physical quantity to its equivalent electrical
signal. There are different types of sensor are available there are: Temperature sensor, Light
sensor, Voltage sensor, Smoke Sensor, Gas sensor, Fire sensor, Magnetic Sensors, etc.
Classification of measurement errors
A good sensor obeys the following rules:
• Is sensitive to the measured property
• Is insensitive to any other property likely to be encountered in its application
• Does not influence the measured property

Ideal sensors are designed to be linear or linear to some simple mathematical function of the
measurement, typically logarithmic. The output signal of such a sensor is linearly proportional to
the value or simple function of the measured property. The sensitivity is then defined as the ratio
between output signal and measured property. For example, if a sensor measures temperature
and has a voltage output, the sensitivity is a constant with the unit [V/K]; this sensor is linear
because the ratio is constant at all points of measurement.
Sensor deviations
If the sensor is not ideal, several types of deviations can be observed:
 The sensitivity may in practice differ from the value specified. This is called a sensitivity
error, but the sensor is still linear.
 Since the range of the output signal is always limited, the output signal will eventually
reach a minimum or maximum when the measured property exceeds the limits. The full
scale range defines the maximum and minimum values of the measured property.
 If the output signal is not zero when the measured property is zero, the sensor has an
offset or bias. This is defined as the output of the sensor at zero input.
 If the sensitivity is not constant over the range of the sensor, this is called nonlinearity.
Usually this is defined by the amount the output differs from ideal behavior over the full
range of the sensor, often noted as a percentage of the full range.
 If the deviation is caused by a rapid change of the measured property over time, there is a
dynamic error. Often, this behavior is described with a bode plot showing sensitivity
error and phase shift as function of the frequency of a periodic input signal.
 If the output signal slowly changes independent of the measured property, this is defined
as drift (telecommunication).
 Long term drift usually indicates a slow degradation of sensor properties over a long
period of time.
 Noise is a random deviation of the signal that varies in time.

 Hysteresis is an error caused by when the measured property reverses direction, but there
is some finite lag in time for the sensor to respond, creating a different offset error in one
direction than in the other.
 If the sensor has a digital output, the output is essentially an approximation of the
measured property. The approximation error is also called digitization error.
 If the signal is monitored digitally, limitation of the sampling frequency also can cause a
dynamic error, or if the variable or added noise noise changes periodically at a frequency
near a multiple of the sampling rate may induce aliasing errors.
 The sensor may to some extent be sensitive to properties other than the property being
measured. For example, most sensors are influenced by the temperature of their
environment.
All these deviations can be classified as systematic errors or random errors. Systematic errors
can sometimes be compensated for by means of some kind of calibration strategy. Noise is a
random error that can be reduced by signal processing, such as filtering, usually at the expense of
the dynamic behavior of the sensor.
Resolution
The resolution of a sensor is the smallest change it can detect in the quantity that it is measuring.
Often in a digital display, the least significant digit will fluctuate, indicating that changes of that
magnitude are only just resolved. The resolution is related to the precision with which the
measurement is made. For example, a scanning tunneling probe (a fine tip near a surface collects
an electron tunneling current) can resolve atoms and molecules.
Different Types Sensor:
1] Acoustic, sound, vibration
 Geophone
 Hydrophone

 Lace Sensor a guitar pickup
 Microphone
 Seismometer
 Accelerometer
2] Automotive, transportation
 Air-fuel ratio meter
 Crank sensor
 Curb feeler, used to warn driver of curbs
 Defect detector, used on railroads to detect axle and signal problems in passing trains
 Engine coolant temperature sensor, or ECT sensor, used to measure the engine
temperature
 Hall effect sensor, used to time the speed of wheels and shafts
 MAP sensor, Manifold Absolute Pressure, used in regulating fuel metering.
 Mass flow sensor, or mass airflow (MAF) sensor, used to tell the ECU the mass of air
entering the engine
 Oxygen sensor, used to monitor the amount of oxygen in the exhaust
 Parking sensors, used to alert the driver of unseen obstacles during parking manoeuvres
 Radar gun, used to detect the speed of other objects
 Speedometer, used measure the instantaneous speed of a land vehicle
 Speed sensor, used to detect the speed of an object
 Throttle position sensor, used to monitor the position of the throttle in an internal
combustion engine

 Tire-pressure monitoring sensor, used to monitor the air pressure inside the tires
 Transmission fluid temperature sensor, used to measure the temperature of the
transmission fluid
 Turbine speed sensor (TSS), or input speed sensor (ISS), used to measure the rotational
speed of the input shaft or torque converter
 Variable reluctance sensor, used to measure position and speed of moving metal
components
 Vehicle speed sensor (VSS), used to measure the speed of the vehicle
 Water sensor or water-in-fuel sensor, used to indicate the presence of water in fuel
 Wheel speed sensor, used for reading the speed of a vehicle's wheel rotation
3] Chemical
 Breathalyzer and Alcohol Sensor
 Carbon dioxide sensor
 Carbon monoxide detector
 Catalytic bead sensor
 Chemical field-effect transistor
 Electrochemical gas sensor
 Electronic nose
 Electrolyte–insulator–semiconductor sensor
 Hydrogen sensor
 Hydrogen sulfide sensor
 Infrared point sensor

 Ion-selective electrode
 Nondispersive infrared sensor
 Microwave chemistry sensor
 Nitrogen oxide sensor
 Olfactometer
 Optode
 Oxygen sensor
 Pellistor
 pH glass electrode
 Potentiometric sensor
 Redox electrode
 Smoke detector
 Zinc oxide nanorod sensor
4] Electric current, electric potential, magnetic, radio
 Ammeter
 Current sensor
 Galvanometer
 Hall effect sensor
 Hall probe
 Leaf electroscope
 Magnetic anomaly detector

 Magnetometer
 Metal detector
 Multi-meter
 Ohmmeter
 Radio direction finder
 Telescope
 Voltmeter
 Voltage detector
 Watt-hour meter
5] Environment, weather, moisture, humidity
 Bedwetting alarm
 Dew warning
 Fish counter
 Gas detector
 Hook gauge evaporimeter
 Hygrometer
 Leaf sensor
 Pyranometer
 Pyrgeometer
 Psychrometer
 Rain gauge

 Rain sensor
 Seismometers
 Snow gauge
 Soil moisture sensor
 Stream gauge
 Tide gauge
6] Flow, fluid velocity
 Air flow meter
 Anemometer
 Flow sensor
 Gas meter
 Mass flow sensor
 Water meter
7] Ionizing radiation, subatomic particles
 Bubble chamber
 Cloud chamber
 Geiger counter
 Neutron detection
 Particle detector
 Scintillation counter
 Scintillator
 Wire chamber

8] Navigation instruments
 Air speed indicator
 Altimeter
 Attitude indicator
 Depth gauge
 Fluxgate compass
 Gyroscope
 Inertial reference unit
 Magnetic compass
 MHD sensor
 Ring laser gyroscope
 Turn coordinator
 Variometer
 Vibrating structure gyroscope
 Yaw rate sensor
9] Position, angle, displacement, distance, speed, acceleration
 Accelerometer
 Capacitive displacement sensor
 Free fall sensor

 Gravimeter
 Inclinometer
 Laser rangefinder
 Linear encoder
 Linear variable differential transformer (LVDT)
 Liquid capacitive inclinometers
 Odometer
 Piezoelectric accelerometer
 Position sensor
 Rotary encoder
 Rotary variable differential transformer
 Selsyn
 Sudden Motion Sensor
 Tilt sensor
 Tachometer
 Ultrasonic thickness gauge
10] Optical, light, imaging
 Charge-coupled device
 Colorimeter
 Contact image sensor
 Electro-optical sensor

 Flame detector
 Infra-red sensor
 LED as light sensor
 Nichols radiometer
 Fiber optic sensors
 Photodetector
 Photodiode
 Photomultiplier tubes
 Phototransistor
 Photoelectric sensor
 Photoionization detector
 Photomultiplier
 Photoresistor
 Photoswitch
 Phototube
 Proximity sensor
 Scintillometer
 Shack-Hartmann
 Wavefront sensor
11] Pressure
 Barograph

 Barometer
 Boost gauge
 Bourdon gauge
 Hot filament ionization gauge
 Ionization gauge
 McLeod gauge
 Oscillating U-tube
 Permanent Downhole Gauge
 Pirani gauge
 Pressure sensor
 Pressure gauge
 Tactile sensor
 Time pressure gauge
12] Force, density, level
 Bhangmeter
 Hydrometer
 Force gauge
 Level sensor
 Load cell
 Magnetic level gauge
 Nuclear density gauge

 Piezoelectric sensor
 Strain gauge
 Torque sensor
 Viscometer
13] Thermal, heat, temperature
 Bolometer
 Calorimeter
 Exhaust gas temperature gauge
 Gardon gauge
 Heat flux sensor
 Infrared thermometer
 Microbolometer
 Microwave radiometer
 Net radiometer
 Resistance temperature detector
 Resistance thermometer
 Silicon bandgap temperature sensor
 Temperature gauge
 Thermistor
 Thermocouple
 Thermometer

14] Proximity, presence
 Alarm sensor
 Motion detector
 Occupancy sensor
 Passive infrared sensor
 Reed switch
 Stud finder
 Triangulation sensor
 Touch switch
 Wired glove
 Doppler radar

Piezoelectric sensor
Piezoelectric sensor:
A piezoelectric sensor is a device that uses the piezoelectric effect to
measure pressure, acceleration, strain or force by converting them to an electrical signal.
Piezoelectric sensors have proven to be versatile tools for the measurement of various
processes. They are used for quality assurance, process control and for research and development
in many different industries it was only in the 1950s that the piezoelectric effect started to be
used for industrial sensing applications. Since then, this measuring principle has been
increasingly used and can be regarded as a mature technology with an outstanding inherent
reliability. It has been successfully used in various applications, such as in medical,
aerospace, nuclear instrumentation, and as a pressure sensor in the touch pads of mobile phones.
In the automotive industry, piezoelectric elements are used to monitor combustion when

developing internal combustion engines. The sensors are either directly mounted into additional
holes into the cylinder head or the spark/glow plug is equipped with a built in miniature
piezoelectric sensor .
The rise of piezoelectric technology is directly related to a
set of inherent advantages. The high modulus of elasticity of
many piezoelectric materials is comparable to that of many
metals and goes up to 10e6 N/m²[
Even though piezoelectric
sensors are electromechanical systems that react to compression,
the sensing elements show almost zero deflection. This is the
reason why piezoelectric sensors are so rugged, have an extremely high natural frequency and an
excellent linearity over a wide amplitude range. Additionally, piezoelectric technology is
insensitive to electromagnetic fields and radiation, enabling measurements under harsh
conditions. Some materials used (especially gallium phosphate or tourmaline) have an extreme
stability even at high temperature, enabling sensors to have a working range of up to 1000°C.
Tourmaline shows pyroelectricity in addition to the piezoelectric effect; this is the ability to
generate an electrical signal when the temperature of the crystal changes. This effect is also
common to piezoceramic materials.
One disadvantage of piezoelectric sensors is that they cannot be used for truly static
measurements. A static force will result in a fixed amount of charges on the piezoelectric
material. While working with conventional readout electronics, imperfect insulating materials,
and reduction in internal sensor resistance will result in a constant loss of electrons, and yield a
decreasing signal. Elevated temperatures cause an additional drop in internal resistance and
sensitivity. The main effect on the piezoelectric effect is that with increasing pressure loads and
temperature, the sensitivity is reduced due to twin-formation. While quartz sensors need to be
cooled during measurements at temperatures above 300°C, special types of crystals like
GaPO4 gallium phosphate do not show any twin formation up to the melting point of the
material itself.

Symbol of Piezo electric sensor
LEAD ACID BATTERY

Lead-acid batteries:
These are the most common in PV systems because their initial cost is lower and
because they are readily available nearly everywhere in the world. There are many different sizes
and designs of lead-acid batteries, but the most important designation is that they are deep cycle
batteries. Lead-acid batteries are available in both wet-cell (requires maintenance) and sealed no-
maintenance versions. AGM and Gel-cell deep-cycle batteries are also popular because they are
maintenance free and they last a lot longer.
Lead acid batteries are reliable and cost effective with an exceptionally long life. The
Lead acid batteries have high reliability because of their ability to withstand overcharge, over
discharge vibration and shock. The use of special sealing techniques ensures that our batteries
are leak proof and non-spillable. Other critical features include the ability to withstand relatively
deeper discharge, faster recovery and more chances of survival if subjected to overcharge. The
batteries have exceptional charge acceptance, large electrolyte volume and low self-discharge,
which make them ideal as zero- maintenance batteries.
Lead acid batteries are manufactured/ tested using CAD (Computer Aided Design). These
batteries are used in Inverter & UPS Systems and have the proven ability to perform under
extreme conditions. The batteries have electrolyte volume, use PE Separators and are sealed in
sturdy containers, which give them excellent protection against leakage and corrosion.
Features
• Manufactured/tested using CAD
• Electrolyte volume
• PE Separators
• Protection against leakage

Number of batteries needed:
If you use the numbers from the sample load numbers link at the end of the page, you
turn out needing 6310W peak and a total of 20950Wh/day. This comes out at 51 Amps peak and
a total of 174 Amp Hours in a day at 120 Volts. To handle these peak loads, it is important to use
electrical wiring of the correct gauge to carry the current. 51 Amps @ 120 Volts (or 526
Amps@12vDC) is hazardous. One should not forget that batteries have a limited life span. Any
system should be designed such that you can easily replace batteries without disrupting much of
your load. You may need to diagnose to determine what batteries have lost their ability to retain
a charge.
Battery connections:
Lead-acid batteries are normally available in blocks of 2V, 6V or 12V. In most cases, to
generate the necessary operating voltage and the capacity of the batteries for the Solar Inverter,
many batteries have to be connected together in parallel and/or in series. Following three
examples are shown:
Parallel Connection:

LED (Light emitting diode):
A light-emitting diode (LED) is a semiconductor light source.[3]
LEDs are used as indicator
lamps in many devices and are increasingly used for otherlighting. Introduced as a practical electronic
component in 1962,[4]
early LEDs emitted low-intensity red light, but modern versions are available
across thevisible, ultraviolet, and infrared wavelengths, with very high brightness.
When a light-emitting diode is forward-biased (switched on), electrons are able
to recombine with electron holes within the device, releasing energy in the form of photons. This effect is
called electroluminescence and the color of the light (corresponding to the energy of the photon) is
determined by the energy gap of the semiconductor. LEDs are often small in area (less than 1 mm2
), and
integrated optical components may be used to shape its radiation pattern.[5]
LEDs present
many advantages over incandescent light sources including lower energy consumption, longer lifetime,
improved robustness, smaller size, and faster switching. LEDs powerful enough for room lighting are
relatively expensive and require more precise current and heat managementthan compact fluorescent
lamp sources of comparable output.
Light-emitting diodes are used in applications as diverse as aviation lighting, automotive lighting,
advertising, general lighting, and traffic signals. LEDs have allowed new text, video displays, and sensors
to be developed, while their high switching rates are also useful in advanced communications technology.
Infrared LEDs are also used in the remote control units of many commercial products including
televisions, DVD players, and other domestic appliances.

Hardware Explanation :
RESISTOR:
Resistors "Resist" the flow of electrical current. The higher the value of resistance (measured in ohms)
the lower the current will be. Resistance is the property of a component which restricts the flow of electric
current. Energy is used up as the voltage across the component drives the current through it and this
energy appears as heat in the component.
Colour Code:

CAPACITOR:
Capacitors store electric charge. They are used with resistors in timing circuits because it takes time
for a capacitor to fill with charge. They are used to smooth varying DC supplies by acting as a reservoir
of charge. They are also used in filter circuits because capacitors easily pass AC (changing) signals but
they block DC (constant) signals.
Circuit symbol:
Electrolytic capacitors are polarized and they must be connected the correct way round, at
least one of their leads will be marked + or -.
Examples:
DIODES:
Diodes allow electricity to flow in only one direction. The arrow of the circuit symbol shows the
direction in which the current can flow. Diodes are the electrical version of a valve and early diodes were
actually called valves.
Circuit symbol:
Diodes must be connected the correct way round, the diagram may be labeled a or + for anode
and k or - for cathode (yes, it really is k, not c, for cathode!). The cathode is marked by a line painted on
the body. Diodes are labeled with their code in small print; you may need
a magnifying glass to read this on small signal diodes.
Example:

LIGHT-EMITTING DIODE (LED):
The longer lead is the anode (+) and the shorter lead is the cathode (&minus). In the schematic
symbol for an LED (bottom), the anode is on the left and the cathode is on the right.
Lighemitting diodes are elements for light signalization in electronics.
They are manufactured in different shapes, colors and sizes. For their low price, low
consumption and simple use, they have almost completely pushed aside other light sources-
bulbs at first place.

It is important to know that each diode will be immediately destroyed unless its current is
limited. This means that a conductor must be connected in parallel to a diode. In order to
correctly determine value of this conductor, it is necessary to know diode’s voltage drop in
forward direction, which depends on what material a diode is made of and what colors it is.
Values typical for the most frequently used diodes are shown in table below: As seen, there are
three main types of LEDs. Standard ones get full brightness at current of 20mA. Low Current
diodes get full brightness at ten time’s lower current while Super Bright diodes produce more
intensive light than Standard ones.
Since the 8051 microcontrollers can provide only low input current and since their pins are
configured as outputs when voltage level on them is equal to 0, direct confectioning to LEDs is carried
out as it is shown on figure (Low current LED, cathode is connected to output pin).
Switches and Pushbuttons:
A push button switch is used to either close or open an electrical circuit depending on the
application. Push button switches are used in various applications such as industrial equipment control
handles, outdoor controls, mobile communication terminals, and medical equipment, and etc. Push button
switches generally include a push button disposed within a housing. The push button may be depressed to
cause movement of the push button relative to the housing for directly or indirectly changing the state of
an electrical contact to open or close the contact. Also included in a pushbutton switch may be an
actuator, driver, or plunger of some type that is situated within a switch housing having at least two
contacts in communication with an electrical circuit within which the switch is incorporated.

Typical actuators used for contact switches include spring loaded force cap actuators that reciprocate
within a sleeve disposed within the canister. The actuator is typically coupled to the movement of the cap
assembly, such that the actuator translates in a direction that is parallel with the cap. A push button switch
for a data input unit for a mobile communication device such as a cellular phone, a key board for
a personal computer or the like is generally constructed by mounting a cover member directly on a circuit
board. Printed circuit board (PCB) mounted pushbutton switches are an inexpensive means of providing
an operator interface on industrial control products. In such push button switches, a substrate which
includes a plurality of movable sections is formed of a rubber elastomeric. The key top is formed on a top
surface thereof with a figure, a character or the like by printing, to thereby provide a cover member. Push
button switches incorporating lighted displays have been used in a variety of applications. Such switches
are typically comprised of a pushbutton, an opaque legend plate, and a back light to illuminate the legend
plate.
Block Diagram For Regulated Power Supply (RPS):
Figure: Power Supply
Description :
Transformer
A transformer is a device that transfers electrical energy from one circuit to another through
inductively coupled conductors—the transformer's coils. A varying current in the first or
primary winding creates a varying magnetic flux in the transformer's core, and thus a varying
magnetic field through the secondary winding. This varying magnetic field induces a varying
electromotive force (EMF) or "voltage" in the secondary winding. This effect is called mutual
induction.

Figure: Transformer Symbol
(or)
Transformer is a device that converts the one form energy to another form of energy like a
transducer.
Figure: Transformer
Basic Principle
A transformer makes use of Faraday's law and the ferromagnetic properties of an iron core to
efficiently raise or lower AC voltages. It of course cannot increase power so that if the voltage is
raised, the current is proportionally lowered and vice versa.

Figure: Basic Principle
Transformer Working
A transformer consists of two coils (often called 'windings') linked by an iron core, as shown in
figure below. There is no electrical connection between the coils; instead they are linked by a
magnetic field created in the core.

Figure: Basic Transformer
Transformers are used to convert electricity from one voltage to another with minimal loss of
power. They only work with AC (alternating current) because they require a changing magnetic
field to be created in their core. Transformers can increase voltage (step-up) as well as reduce
voltage (step-down).
Alternating current flowing in the primary (input) coil creates a continually changing magnetic
field in the iron core. This field also passes through the secondary (output) coil and the changing
strength of the magnetic field induces an alternating voltage in the secondary coil. If the
secondary coil is connected to a load the induced voltage will make an induced current flow. The
correct term for the induced voltage is 'induced electromotive force' which is usually abbreviated
to induced e.m.f.
The iron core is laminated to prevent 'eddy currents' flowing in the core. These are currents
produced by the alternating magnetic field inducing a small voltage in the core, just like that
induced in the secondary coil. Eddy currents waste power by needlessly heating up the core but
they are reduced to a negligible amount by laminating the iron because this increases the
electrical resistance of the core without affecting its magnetic properties.
Transformers have two great advantages over other methods of changing voltage:
1. They provide total electrical isolation between the input and output, so they can be safely
used to reduce the high voltage of the mains supply.

2. Almost no power is wasted in a transformer. They have a high efficiency (power out /
power in) of 95% or more.
Classification of Transformer
 Step-Up Transformer
 Step-Down Transformer
Step-Down Transformer
Step down transformers are designed to reduce electrical voltage. Their primary voltage is
greater than their secondary voltage. This kind of transformer "steps down" the voltage applied
to it. For instance, a step down transformer is needed to use a 110v product in a country with a
220v supply.
Step down transformers convert electrical voltage from one level or phase configuration usually
down to a lower level. They can include features for electrical isolation, power distribution, and
control and instrumentation applications. Step down transformers typically rely on the principle
of magnetic induction between coils to convert voltage and/or current levels.
Step down transformers are made from two or more coils of insulated wire wound around a core
made of iron. When voltage is applied to one coil (frequently called the primary or input) it
magnetizes the iron core, which induces a voltage in the other coil, (frequently called the
secondary or output). The turn’s ratio of the two sets of windings determines the amount of
voltage transformation.

Figure: Step-Down Transformer
An example of this would be: 100 turns on the primary and 50 turns on the secondary, a ratio of
2 to 1.
Step down transformers can be considered nothing more than a voltage ratio device.
With step down transformers the voltage ratio between primary and secondary will mirror the
"turn’s ratio" (except for single phase smaller than 1 kva which have compensated secondary). A
practical application of this 2 to 1 turn’s ratio would be a 480 to 240 voltage step down. Note that
if the input were 440 volts then the output would be 220 volts. The ratio between input and
output voltage will stay constant. Transformers should not be operated at voltages higher than
the nameplate rating, but may be operated at lower voltages than rated. Because of this it is
possible to do some non-standard applications using standard transformers.
Single phase step down transformers 1 kva and larger may also be reverse connected to step-
down or step-up voltages. (Note: single phase step up or step down transformers sized less than 1
KVA should not be reverse connected because the secondary windings have additional turns to
overcome a voltage drop when the load is applied. If reverse connected, the output voltage will
be less than desired.)
Step-Up Transformer
A step up transformer has more turns of wire on the secondary coil, which makes a larger
induced voltage in the secondary coil. It is called a step up transformer because the voltage
output is larger than the voltage input.
Step-up transformer 110v 220v design is one whose secondary voltage is greater than its primary
voltage. This kind of transformer "steps up" the voltage applied to it. For instance, a step up
transformer is needed to use a 220v product in a country with a 110v supply.
A step up transformer 110v 220v converts alternating current (AC) from one voltage to another
voltage. It has no moving parts and works on a magnetic induction principle; it can be designed
to "step-up" or "step-down" voltage. So a step up transformer increases the voltage and a step
down transformer decreases the voltage.

The primary components for voltage transformation are the step up transformer core and coil.
The insulation is placed between the turns of wire to prevent shorting to one another or to
ground. This is typically comprised of Mylar, nomex, Kraft paper, varnish, or other materials. As
a transformer has no moving parts, it will typically have a life expectancy between 20 and 25
years.
Figure: Step-Up Transformer
Applications :
Generally these Step-Up Transformers are used in industries applications only.
Types of Transformer
Mains Transformers
Mains transformers are the most common type. They are designed to reduce the AC mains
supply voltage (230-240V in the UK or 115-120V in some countries) to a safer low voltage.
The standard mains supply voltages are officially 115V and 230V, but 120V and 240V are the
values usually quoted and the difference is of no significance in most cases.
Figure: Main Transformer

To allow for the two supply voltages mains transformers usually have two separate primary coils
(windings) labeled 0-120V and 0-120V. The two coils are connected in series for 240V (figure
2a) and in parallel for 120V (figure 2b). They must be wired the correct way round as shown in
the diagrams because the coils must be connected in the correct sense (direction):
Most mains transformers have two separate secondary coils (e.g. labeled 0-9V, 0-9V) which may
be used separately to give two independent supplies, or connected in series to create a centre-
tapped coil (see below) or one coil with double the voltage.
Some mains transformers have a centre-tap halfway through the secondary coil and they are
labeled 9-0-9V for example. They can be used to produce full-wave rectified DC with just two
diodes, unlike a standard secondary coil which requires four diodes to produce full-wave
rectified DC.
A mains transformer is specified by:
1. Its secondary (output) voltages Vs.
2. Its maximum power, Pmax, which the transformer can pass, quoted in VA (volt-amp). This
determines the maximum output (secondary) current, Imax...

...where Vs is the secondary voltage. If there are two secondary coils the maximum
power should be halved to give the maximum for each coil.
3. Its construction - it may be PCB-mounting, chassis mounting (with solder tag
connections) or toroidal (a high quality design).
Audio Transformers
Audio transformers are used to convert the moderate voltage, low current output of an audio
amplifier to the low voltage, high current required by a loudspeaker. This use is called
'impedance matching' because it is matching the high impedance output of the amplifier to the
low impedance of the loudspeaker.
Figure: Audio transformer
Radio Transformers
Radio transformers are used in tuning circuits. They are smaller than mains and audio
transformers and they have adjustable ferrite cores made of iron dust. The ferrite cores can be
adjusted with a non-magnetic plastic tool like a small screwdriver. The whole transformer is
enclosed in an aluminum can which acts as a shield, preventing the transformer radiating too
much electrical noise to other parts of the circuit.
Figure: Radio Transformer

Turns Ratio and Voltage
The ratio of the number of turns on the primary and secondary coils determines the ratio of the
voltages...
...where Vp is the primary (input) voltage, Vs is the secondary (output) voltage, Np is the number
of turns on the primary coil, and Ns is the number of turns on the secondary coil.
Diodes
Diodes allow electricity to flow in only one direction. The arrow of the circuit symbol shows the
direction in which the current can flow. Diodes are the electrical version of a valve and early
diodes were actually called valves.
Figure: Diode Symbol
A diode is a device which only allows current to flow through it in one direction. In this
direction, the diode is said to be 'forward-biased' and the only effect on the signal is that there
will be a voltage loss of around 0.7V. In the opposite direction, the diode is said to be 'reverse-
biased' and no current will flow through it.
Rectifier

The purpose of a rectifier is to convert an AC waveform into a DC waveform (OR) Rectifier
converts AC current or voltages into DC current or voltage. There are two different rectification
circuits, known as 'half-wave' and 'full-wave' rectifiers. Both use components called diodes to
convert AC into DC.
The Half-wave Rectifier
The half-wave rectifier is the simplest type of rectifier since it only uses one diode, as shown in
figure.
Figure: Half Wave Rectifier
Figure 2 shows the AC input waveform to this circuit and the resulting output. As you can see,
when the AC input is positive, the diode is forward-biased and lets the current through. When
the AC input is negative, the diode is reverse-biased and the diode does not let any current
through, meaning the output is 0V. Because there is a 0.7V voltage loss across the diode, the
peak output voltage will be 0.7V less than Vs.

Figure: Half-Wave Rectification
While the output of the half-wave rectifier is DC (it is all positive), it would not be suitable as a
power supply for a circuit. Firstly, the output voltage continually varies between 0V and Vs-
0.7V, and secondly, for half the time there is no output at all.
The Full-wave Rectifier
The circuit in figure 3 addresses the second of these problems since at no time is the output
voltage 0V. This time four diodes are arranged so that both the positive and negative parts of the
AC waveform are converted to DC. The resulting waveform is shown in figure 4.

Figure: Full-Wave Rectifier
Figure: Full-Wave Rectification
When the AC input is positive, diodes A and B are forward-biased, while diodes C and D are
reverse-biased. When the AC input is negative, the opposite is true - diodes C and D are
forward-biased, while diodes A and B are reverse-biased.
While the full-wave rectifier is an improvement on the half-wave rectifier, its output still isn't
suitable as a power supply for most circuits since the output voltage still varies between 0V and
Vs-1.4V. So, if you put 12V AC in, you will 10.6V DC out.
Capacitor Filter
The capacitor-input filter, also called "Pi" filter due to its shape that looks like the Greek letter
pi, is a type of electronic filter. Filter circuits are used to remove unwanted or undesired
frequencies from a signal.

Figure: Capacitor Filter
A typical capacitor input filter consists of a filter capacitor C1, connected across the rectifier
output, an inductor L, in series and another filter capacitor connected across the load.
1. The capacitor C1 offers low reactance to the AC component of the rectifier output while
it offers infinite reactance to the DC component. As a result the capacitor shunts an
appreciable amount of the AC component while the DC component continues its journey
to the inductor L
2. The inductor L offers high reactance to the AC component but it offers almost zero
reactance to the DC component. As a result the DC component flows through the
inductor while the AC component is blocked.
3. The capacitor C2 bypasses the AC component which the inductor had failed to block. As
a result only the DC component appears across the load RL.
Figure: Centered Tapped Full-Wave Rectifier with a Capacitor Filter

Voltage Regulator
A voltage regulator is an electrical regulator designed to automatically maintain a constant
voltage level. It may use an electromechanical mechanism, or passive or active electronic
components. Depending on the design, it may be used to regulate one or more AC or DC
voltages. There are two types of regulator are they.
 Positive Voltage Series (78xx) and
 Negative Voltage Series (79xx)
78xx:
’78’ indicate the positive series and ‘xx’indicates the voltage rating. Suppose 7805 produces
the maximum 5V.’05’indicates the regulator output is 5V.
79xx:
’78’ indicate the negative series and ‘xx’indicates the voltage rating. Suppose 7905
produces the maximum -5V.’05’indicates the regulator output is -5V.
These regulators consists the three pins there are
Pin1: It is used for input pin.
Pin2: This is ground pin for regulator
Pin3: It is used for output pin. Through this pin we get the output.
Figure: Regulator

UNIDIRECTIONAL CURRENT CONTROLLER :
Here in the place of unidirectional current controller we are using diodes which allow electricity
to flow in only one direction. The arrow of the circuit symbol shows the direction in which the
current can flow. Diodes are the electrical version of a valve and early diodes were actually
called valves.
Figure: Diode Symbol
A diode is a device which only allows current to flow through it in one direction. In this
direction, the diode is said to be 'forward-biased' and the only effect on the signal is that there
will be a voltage loss of around 0.7V. In the opposite direction, the diode is said to be 'reverse-
biased' and no current will flow through it. By connecting this device the current cannot flow in
reverse direction from battery.

Inverter:
An inverter is an electrical device that converts direct current (DC) to alternating
current (AC); the converted AC can be at any required voltage and frequency with the use of
appropriate transformers, switching, and control circuits.
Solid-state inverters have no moving parts and are used in a wide range of applications,
from small switching power supplies in computers, to large electric utility high-voltage direct
current applications that transport bulk power. Inverters are commonly used to supply AC power
from DC sources such as solar panels or batteries.
There are two main types of inverter. The output of a modified sine wave inverter is
similar to a square wave output except that the output goes to zero volts for a time before
switching positive or negative. It is simple and low cost and is compatible with most electronic
devices, except for sensitive or specialized equipment, for example certain laser printers. A pure
sine wave inverter produces a nearly perfect sine wave output (<3% total harmonic distortion)
that is essentially the same as utility-supplied grid power. Thus it is compatible with all AC
electronic devices. This is the type used in grid-tie inverters. Its design is more complex, and
costs 5 or 10 times more per unit power . The electrical inverter is a high-power electronic
oscillator. It is so named because early mechanical AC to DC converters were made to work in
reverse, and thus were "inverted", to convert DC to AC.
The inverter performs the opposite function of a rectifier.
Symbol of Inverter

Circuit description:
In one simple inverter circuit, DC power is connected to a transformer through the centre
tap of the primary winding. A switch is rapidly switched back and forth to allow current to flow
back to the DC source following two alternate paths through one end of the primary winding and
then the other. The alternation of the direction of current in the primary winding of the
transformer produces alternating current (AC) in the secondary circuit.
The electromechanical version of the switching device includes two stationary contacts
and a spring supported moving contact. The spring holds the movable contact against one of the
stationary contacts and an electromagnet pulls the movable contact to the opposite stationary
contact. The current in the electromagnet is interrupted by the action of the switch so that the
switch continually switches rapidly back and forth. This type of electromechanical inverter
switch, called a vibrator or buzzer, was once used in vacuum tube automobile radios. A similar
mechanism has been used in door bells, buzzers and tattoo guns.

As they became available with adequate power ratings, transistors and various other types
of semiconductor switches have been incorporated into inverter circuit designs.
BULB:
A bulb is a short stem with fleshy leaves or leaf bases. The leaves often function
as food storage organs during dormancy .
A bulb's leaf bases generally do not support leaves, but contain food reserves to enable
the plant to survive adverse conditions. The leaf bases may resemble scales, or they may overlap
and surround the center of the bulb as with the onion. A modified stem forms the base of the
bulb, and plant growth occurs from this basal plate. Roots emerge from the underside of the base,
and new stems and leaves from the upper side.
Other types of storage organs (such as corms, rhizomes, and tubers) are sometimes
erroneously referred to as bulbs. The correct term for plants that form underground storage
organs, including bulbs as well as tubers and corms, is geophytes.
Some epiphytic orchids (family Orchidaceous) form above-ground storage organs called pseudo
bulbs that superficially resemble bulbs.
Incandescent:
These are the standard bulbs that most people are familiar with. Incandescent bulbs work
by using electricity to heat a tungsten filament in the bulb until it glows. The filament is either in
a vacuum or in a mixture of argon/nitrogen gas. Most of the energy consumed by the bulb is
given off as heat, causing its Lumens per Watt performance to be low. Because of the filament's

high temperature, the tungsten tends to evaporate and collect on the sides of the bulb. The
inherent imperfections in the filament causes it to become thinner unevenly. When a bulb is
turned on, the sudden surge of energy can cause the thin areas to heat up much faster than the
rest of the filament, which in turn causes the filament to break and the bulb to burn out.
Incandescent bulbs produce a steady warm, light that is good for most household applications. A
standard incandescent bulb can last for 700-1000 hours, and can be used with a dimmer. Soft
white bulbs use a special coating inside the glass bulb to better diffuse the light; but the light
color is not changed.
Halogen:
Halogen bulbs are a variation of incandescent bulb technology. These bulbs work by
passing electricity through a tungsten filament, which is enclosed in a tube containing halogen
gas. This halogen gas causes a chemical reaction to take place which removes the tungsten from
the wall of the glass and deposits it back onto the filament. This extends the life of the bulb. In
order for the chemical reaction to take place, the filament needs to be hotter than what is needed
for incandescent bulbs. The good news is that a hotter filament produces a brilliant white light
and is more efficient (more lumens per watt).
The bad news is that a hotter filament means that the tungsten is evaporating that much
faster. Therefore a denser, more expensive fill gas (krypton), and a higher pressure, are used to
slow down the evaporation. This means that a thicker, but smaller glass bulb (envelope) is
needed, which translates to a higher cost. Due to the smaller glass envelope (bulb), the halogen
bulb gets much hotter than other bulbs. A 300 watt bulb can reach over 300 degrees C. Therefore
attention must be paid to where halogen bulbs are used, so that they don't accidentally come in
contact with flammable materials, or burn those passing by.

Care must be taken not to touch the glass part of the bulb with our fingers. The oils from
our fingers will weaken the glass and shorten the bulb’s life. Many times this causes the bulb to
burst when the filament finally burns out.
To summarize, the halogen has the advantage of being more efficient (although not by
much) and having longer life than the incandescent bulb. They are relatively small in size and are
dimmable. The disadvantages are that they are more expensive, and burn at a much higher
temperature, which could possibly be a fire hazard in certain areas.
Fluorescent:
These bulbs work by passing a current through a tube filled with argon gas and mercury.
This produces ultraviolet radiation that bombards the phosphorous coating causing it to emit
light (see: “How Fluorescents Work”). Bulb life is very long - 10,000 to 20,000 hours.
Fluorescent bulbs are also very efficient, producing very little heat. A common misconception is
that all fluorescent lamps are neutral or cool in color appearance and do not have very good
color-rendering ability. This is largely due to the fact that historically the "cool white"
fluorescent lamp was the industry standard. It had a very cool color appearance (4200K) and
poor CRI rating. This is simply no longer the case. Regarding color, a wide variety of fluorescent
lamps , using rare-earth tri-phosphor technology, offer superior color rendition and a wide range
of color temperature choices (from 2700K to 5000K and higher). Fluorescent bulbs are ideal for
lighting large areas where little detail work will be done (e.g. basements, storage lockers, etc.).
With the new type bulbs, and style of fixtures coming out, fluorescents can be used in most
places around the home. Most fluorescent bulb cannot be used with dimmers.

That fluorescent bulb need components called ballasts to provide the right amount of
voltage. There are primarily two types - magnetic and electronic. Electronic ballasts solve some
of the flickering and humming problems associated with magnetic ballast, and are more efficient,
but cost more to purchase. Some ballasts need a “starter” to work along with it. Starters are sort
of small mechanical timers, needed to cause a stream of electrons to flow across the tube and
ionize the mercury vapor
On tube type fluorescent bulbs, the letter T designates that the bulb is tubular in shape.
The number after it expresses the diameter of the bulb in eighths of an inch.

WORKING PROCEDURE:
1. By using Foot step power generation project we can generate the D.C voltage and
store it in the rechargeable battery.
2. This voltage we are converting into the AC voltage by using converter. And we can
operate AC loads also.
3. Foot step board it consist of a 16 piezo electric sensors which are connected in
parallel.
4. When the pressure is applied on the sensors, the sensors will convert mechanical
energy into electrical energy.
5. This electrical energy will be storing into the 12v rechargeable battery.
6. This voltage we are giving to the inverter.
7. Inverter is used to converts DC voltage to AC voltage.
8. By using this AC voltage we can operate AC loads.

Advantages :
• Reliable, Economical, Eco-Friendly.
• Less consumption of Non- renewable energies.
• Power generation is simply walking on the step
• Power also generated by running or exercising on the step.
• No need fuel input
• This is a Non-conventional system
• Battery is used to store the generated power

Applications:
• Foot step generated power can be used for agricultural, home applications, streeght-
lightining.
• Foot step power generation can be used in emergency power failure situations.
• Metros, Rural Applications etc.,

CONCLUSION :
The project “FOOT STEP POWER GENERATION FOR RURAL
ENERGY APPLICATION TO RUN A.C. AND D.C. LOADS” is successfully tested and
implemented which is the best economical, affordable energy solution to common people. This
can be used for many applications in rural areas where power availability is less or totally
absence. As India is a developing country where energy management is a big challenge for huge
population. By using this project we can drive both a.c. as well as D.C loads according to the
force we applied on the piezo electric sensor.

REFERENCE:
• www.howstuffworks.com
• www.answers.com
• EMBEDDED SYSTEM BY RAJ KAMAL
• Magazines:
• www.Electronics for you.com
• www.Electrikindia.com

Footstep power generation

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