Electronics project

1. THE ISLAMIC UNIVERSITY OF GAZA
ELECTRICAL ENGINEERING DEPARTMENT
ELECTRONCS II LAB
Prepared by:
Sanabel Nasser EL-Haddad 220170536
Tasneem Deyab AL-Tater 220171452
Amal Asaad Asaad 220170449
Submitted for:
Eng. Heba Zeyad EL-Ghosain
Teacher assistant
January,2020

2. 1
Abstract
As the energy demand and environmental problems increase, natural energy
sources have become very important as an alternative to conventional energy
sources. The renewable energy sector is fast gaining ground as a new growth area
for numerous countries with the vast potential it presents environmentally and
economically. Solar energy plays an important role as a primary source of energy,
especially for the ruler area. This project aims at the development of the process to
track the sun and attain maximum efficiency using LM324 AND LDR Sensor for
real-time monitoring. The project's hardware development, two light-dependent
resistor (LDR) has been used for capturing maximum light source. Motor has been
used to move the solar panel at maximum light source location-sensing by LDR.
The performance of the system has been tested and compared with a static solar
panel. This project describes the design of a low cost, solar tracking system. In this
project, a single axis solar tracking system has been developed by which more
energy from the sun can be harnessed. In this project, LM324 has been used as the
main controlling unit. To detect the position of the sun on the sky, two LDRs have
been used and to rotate the orientation of the Solar PV panel a motor has been
used. The sensors and servo motor have properly been interfaced. The motor has
been mechanically coupled with the PV panel. The whole system has been
assembled and its performance has been tested. This tracker changes the direction
of the solar panel based on the direction of the sun-facing to the panel successfully.
Single-axis solar tracker tracks the sun daily and makes the solar panel more
efficient.

3. 2
Contents
Chapter 1 …………..………….……………………………………………………...4
1.1 Introduction ……………………………………..……………............................4
Chapter 2 ……..….…………………………………………………………………. 5
2.1 Component of circuit ……………………..……………………..….……..…...5
2.2 Details of Components ………………………………..…………….………….5
Chapter 3……………….…………………………..……………………………… 16
3.1 The reference circuit we use …………………..………..………………......... 16
3.2 Simulation the Circuit in Proteus ….……………….……………………….... 16
3.3 Work Mechanism …………………………………………….……..………... 17
Chapter 4 ……………………………………………..…….…………………..... 19
4.1 Features ………………………………………….…………………………..... 19
4.2 Advantages…..................................................................................................... 19
4.3 Disadvantages…................................................................................................. 19
Chapter 5 …………………………………………………………..…………….... 20
5.1 The Result …………………………………………………………………….. 20
5.2 Future Directions ……………………………………………………………... 20
5.3 Conclusion ………………………...………………………………….............. 21
Chapter 6 ……………………………………………….....…….………………… 22
Reference …………………………………………………………………...……... 22

4. 3
List of Figures
Figure 2.1 Solar Panel ………..……………………………………………………… 6
Figure 2.2 LM324 ………………………..………………………………………….. 7
Figure 2.3 LDR…………………………..…………………………………….…….. 8
Figure 2.4 DC Gear Motor………………………………………………….…………9
Figure 2.5 Battery……………………………………………………………….……. 9
Figure 2.6 BD139 Transistor Pinout ……………………………………..………….10
Figure 2.7 BD140 Transistor Pinout ………..……………………………………….12
Figure 2.8 Diode 1N4148 ………..…………………………………………...…….. 13
Figure 2.9 Capacitor ………..…………………………………………………...….. 13
Figure 2.10 Variable Resistor ………..………………………………….………….. 14
Figure 2.11 Resistor ………..……………………………………………………..... 14
Figure 2.12 Connection Wires ………..………………………………...………….. 15
Figure 3.1 Reference circuit ………..………………………………………...…….. 16
Figure 3.2 Schematic Circuit using proteus ………………………………...…….. 16
Figure 3.3 PCB Circuit using proteus…………………………………………….….17
Fig 5.1 Result ………………………………………………………………….…….20

5. 4
Chapter 1
Introduction
The conversion of solar light into electrical energy represents one of the most
promising and challenging energetic technologies, in continuous development,
being clean, silent and reliable, with very low maintenance costs and minimal
ecological impact. A photovoltaic panel is a device used to capture the suns
radiation. These panels consist of an array of solar cells. The solar cells are made
up of silicon (sand). They are then connected to complete a photovoltaic (solar)
panel. When the sunrays are incident on the solar cells, due to the photovoltaic
effect, light energy from the sun is used to convert it to electrical energy. We know
that most of the energy gets absorbed, when the panels surface is perpendicular to
the sun. Stationary mounted PV (photo voltaic) panels are only perpendicular to
sun once a day but the challenge for is to get maximum energy from the source, so
for it we use checkers on which the whole system is mounted. In tracking system,
solar panels move according to the movement of sun throughout the day. There are
three methods of tracking: active, passive, chronological and manual tracking
systems. In active tracking system, the position of the sun is determined by the
sensors .These sensors will trigger the motor to move the mounting system so that
the panels will always face the sunrays perpendicular to it throughout the day .But
in this system it is very difficult for sensors to determine the position of sun in
cloudy days. So it is not a very accurate. In its Passive tracking systems, which
determines the position of the sun by moving the panels in response to an
imbalance pressure between the two points at both ends of the trackers. The
imbalance pressure caused by solar heat creates a gas pressure on a low boiling
point compressed gas fluid that is driven to one side or the other accordingly,
which then moves the system. This method is also not accurate as the shade
/reflectors that are used to reflect early morning sunlight to “wake up” the panel
and tilt it towards the sun can take nearly an hour to do so. A chronological tracker
is a timer-based tracking system whereby the structure is moved at a fixed rate
throughout the day. The theory behind this is that the sun moves across the sky at a
fixed rate .Thus the motor or actuator is programmed to continuously rotate at a
„slow average rate of one revolution per day (15 degrees per hour). This method of
sun-tracking is very accurate. However, the continuous rotation of the motor or
actuator means more power consumption and tracking the sun. In manual tracking
system, drives are replaced by operators who adjust the trackers. This has the
benefits of robustness, having staff available for maintenance and creating
employment for the population in the vicinity of the site. Tracker systems follow
the sun throughout the day to maximize energy output. The Solar Tracker is a
proven single-axis tracking technology that has been custom designed to integrate
with solar modules and reduce system costs. The Solar Tracker generates up to
25% more energy than fixed mounting systems and provides a bankable energy
production profile preferred by utilities [1].

6. 5
Chapter 2
2.1 Component of circuit
 Solar panel
 2 BD140 Transistor
 2 BD139 Transistor
 DC Voltage Source
 Connection wires
 Resistor ( 15KΩ , 47KΩ )
 Variable resistors (100k ,10k)
 100nF Capacitor
 4 Diode (1N4148)
 2 LDR (Light Dependent Resistors )
 DC Gear Motor
2.2 Components Details
 Solar panel
- Solar panels are devices that convert light into electricity. They are called
"solar" panels because most of the time, the most powerful source of light
available is the Sun, called Sol by astronomers. Some scientists call them
photovoltaic which means, basically, "light-electricity".
- A solar panel is a collection of solar cells spread over a large area and can
work together to provide enough power to be useful. The more light that hits a
cell, the more electricity it produces[1].

7. 6
Figure 2.1 Solar Panel
 LM324:
The LM324 series are low−cost, quad operational amplifiers with true
differential inputs. They have several distinct advantages over standard
operational amplifier types in single supply applications. The quad amplifier can
operate at supply voltages as low as 3.0 V or as high as 32 V with quiescent
currents about one−fifth of those associated with the MC1741 (on a per amplifier
basis). The common mode input range includes the negative supply, thereby
eliminating the necessity for external biasing components in many applications.
The output voltage range also includes the negative power supply voltage [2].
Features:
• Short Circuited Protected Outputs .
• True Differential Input Stage .
• Single Supply Operation: 3.0 V to 32 V .
• Low Input Bias Currents: 100 nA Maximum (LM324A) .
• Internally Compensated .
• Common Mode Range Extends to Negative Supply .
• Industry Standard Pinouts .
• ESD Clamps on the Inputs Increase Ruggedness without Affecting Device
Operation .
• NCV Prefix for Automotive and Other Applications Requiring Unique Site
and Control Change Requirements; AEC−Q100 Qualified and PPAP Capable.
• These Devices are Pb−Free, Halogen Free/BFR Free and are RoHS Compliant.

8. 7
Figure 2.2 LM324
 Light Dependent Resistors
A photoresistor (or light-dependent resistor, LDR, or photo-conductive cell) is a
light-controlled variable resistor. The resistance of a photoresistor decreases
with increasing incident light intensity; in other words, it exhibits
photoconductivity. A photoresistor can be applied in light-sensitive detector
circuits and light-activated and dark-activated switching circuits.A photoresistor
is made of a high resistance semiconductor. In the dark, a photoresistor can have
a resistance as high as several mega ohms (MΩ), while in the light, a
photoresistor can have a resistance as low as a few hundred ohms. If incident
light on a photoresistor exceeds a certain frequency, photons absorbed by the
semiconductor give bound electrons enough energy to jump into the conduction
band. The resulting free electrons (and their hole partners) conduct electricity,
thereby lowering resistance. The resistance range and sensitivity of a
photoresistor can substantially differ among dissimilar devices. Moreover,
unique photoresistors may react substantially differently to photons within
certain wavelength bands.

9. 8
The solar tracker system will obtain its data from two CDS (Cadmium Sulfide)
photocells, which are type of LDR. The material used in CDS photocell is of
high resistance semiconductor. Therefore, once light falls on its surface,
photons absorbed by the semiconductor will give bound electrons enough
energy to jump into the conduction band. As a result, free electrons conduct
electricity and thus lower the resistance. In case of high intensity, the photocell
will produce the lowest resistance, the opposite will occur in case of complete
darkness [1].
Figure 2.3 LDR
 DC Gear Motor :
Gear motor is an all-in-one combination of a motor and gearbox. The addition
of a gear head to a motor reduces the speed while increasing the torque output.
The most important parameters in regards to gear motors are speed (rpm),
torque (lb-in) and efficiency (%). In order to select the most suitable gear
motor for any application then it must first compute the load, speed and torque
requirements for that application[1].

10. 9
Figure 2.4 DC Gear Motor
 Battery:
An electric battery is a device consisting of one or more electrochemical
cells with external connections provided to power electrical devices such
as flashlights, and electric cars. When a battery is supplying electric power, its
positive terminal is the cathode and its negative terminal is the anode. The
terminal marked negative is the source of electrons that will flow through an
external electric circuit to the positive terminal. When a battery is connected to
an external electric load[1].
Figure 2.5 Battery

11. 11
 BD139 Transistor:
 Pin Configuration
Pin
Number
Pin
Name
Description
1 Emitter Current Drains out through emitter, normally connected to
ground
2 Collector Current flows in through collector, normally connected to
load
3 Base Controls the biasing of transistor, Used to turn ON or OFF the
transistor.
Figure 2.6 BD139 Transistor Pinout
 Features
 Plastic casing NPN Transistor
 Continuous Collector current (IC) is 1.5A
 Collector-Emitter voltage (VCE) is 80 V
 Collector-Base voltage (VCB) is 80V
 Emitter Base Breakdown Voltage (VBE) is 5V
 DC current gain (hfe) is 40 to 160
 Available in To-225 package
 BD140 Transistor:
 Features / technical specifications:
 Package Type: TO-126
 Transistor Type: PNP
 Max Collector Current(IC): -1.5A
 Max Collector-Emitter Voltage (VCE): –80V

12. 11
 Max Collector-Base Voltage (VCB): –80V
 Max Emitter-Base Voltage (VEBO): –5V
 Max Collector Dissipation (Pc): 12.5 Watt
 Max Transition Frequency (fT): 190 MHz
 Minimum & Maximum DC Current Gain (hFE): 25 – 250
 Max Storage & Operating temperature Should Be: -55 to +150
Centigrade
 Description:
BD140 is a famous PNP type transistor, it is used in many electronics
circuits, this transistor can handle current upto 1.5A or 1500mA, due to
which it can be used to drive loads upto 1.5A in electronic circuits, for
example high power LEDs, relays, motors and more, with these features it
has lots of other features like its high collector emitter and collector base
voltage that is 80 volts, make it an ideal transistor to use in circuits using 80
volts DC or below 80 volts. Moreover the collector dissipation of this
transistor is around 12.5 watt due to which it’s a good transistor to use in
audio amplifier circuits. The minimum base voltage or saturation voltage of
the transistor is -0.5V [2].
 Applications:
 Audio Amplifiers
 Switching Loads under 1.5A
 Battery Chargers
 Power Supplies
 Motor Driver
 Darlington Pair [3]

13. 12
Figure 2.7 BD140 Transistor Pinout
 Diode 1N4148 :
1N4148 is a standard diode made up of silicon and is used for extremely fast
switching operations. It has two modes of operation named as:
 Forward Biased
 Reverse Biased
In Forward Biased operational mode, it allows the current to pass though it and it
acts as a closed switch, while in Reverse Biased operational mode it acts as an
open switch and doesn’t allow the current to pass through it [4].
1N4148 Applications:
 Extremely fat switching purposes.
 High-speed rectification.
 General purpose switching.
 Protection circuits in telecommunication industries, offices, homes etc.
 These were few of the applications associated with this switching diode.

14. 13
Figure 2.8 Diode 1N4148
 Capacitor :
- A capacitor can store electric energy when it is connected to its charging
circuit. And when it is disconnected from its charging circuit, it can
dissipate that stored energy, so it can be used like a temporary battery.
Capacitors are commonly used in electronic devices to maintain power
supply while batteries are being changed.
- Capacitor in the ac circuit is used to improve the power factor of the load
which is inductive.
- Capacitor in DC circuits is used to keep control signal voltage/current
constant and ripple-free as a voltage across the capacitor can not change
suddenly and when there is a change in voltage, the capacitor opposes this
change and try to keep voltage unchanged.
Figure 2.9 Capacitor

15. 14
 Variable Resistors :
A variable resistor is a resistor of which the electric resistance value can be
adjusted. A variable resistor is in essence an electro-mechanical transducer and
normally works by sliding a contact (wiper) over a resistive element. When a
variable resistor is used as a potential divider by using 3 terminals it is called a
potentiometer. When only two terminals are used, it functions as a variable
resistance and is called a rheostat. Electronically controlled variable resistors
exist, which can be controlled electronically instead of by mechanical action.
These resistors are called digital potentiometers[5].
Figure 2.10 Variable Resistor
 Resistors :
- It is an electrical device may be a passive two-terminal electrical part that
implements resistance as a circuit component. In electronic circuits,
resistors unit of measurement accustomed reduce current flow, alter signal
levels, to divide voltages, bias active components, and terminate
transmission lines, among completely different uses.
Figure 2.11 Resistor

16. 15
 Connection wire:
A Few connecting wires are used for connection the circuit with the tank or
otherwise.
Figure 2.12 Connection Wires

17. 16
Chapter 3
In this chapter we will talk about the circuit that makes up the project in detail.
1.1 Reference circuit we use:
Figure 3.1 Reference circuit
3.2 Simulation the Circuit in Proteus:
We connect the circuit using Proteus, the schematic shown in Figure 3.2 and PCB
shown in Figure 3.3.
Figure 3.2 Schematic Circuit using proteus

18. 17
Figure 3.3 PCB Circuit using proteus
3.3 Work Mechanism:
 LDR's Circuit Works
The position of the LDRs are critical here and the set of LDR which corresponds
to this vertical plane movement is so positioned that it senses the sunlight
accurately and tries to keep the panel perpendicular to the sun rays by moving
the motor in the appropriate direction through a definite number of stepped
rotations.
This motion takes place in response to the position of the sun during the
seasonal changes, therefore in contrast to the vertical movements; this operation
is very gradual and cannot be experienced daily.
Again the above motion is in response to the command given to the motor by the
electronic circuit which operates in response to the sensing done by the LDRs.

19. 18
 Solar Tracker's Op-Amp Controls Circuit Function
A careful investigation of the circuit shown in the diagram reveals that the
whole configuration is very simple and straightforward. Here a single IC 324 is
utilized and only two of its op-amps are employed for the required operations
The op-amps are primarily wired to form a kind of window comparator,
responsible for activating their outputs whenever their inputs waver or drift out
of the predetermined window, set by the relevant pots.
Two LDRs are connected to the inputs of the op-amps for sensing the light
levels. As long as the lights over the two LDRs are uniform, the outputs of the
op-amp remain deactivated.
However the moment one of the LDRs senses a different magnitude of light
over it (which may happen due to the changing position of the sun) the balance
over the input of the op-amp shift toward one direction, immediately making
the output of the relevant op-amp go high.
This high output instantly activates the full-bridge transistor network, which in
turn rotates the connected motor in a set direction, such that the panel rotates
and adjusts its alignment with the sunrays until uniform amount of light is
restored over the relevant set of LDRs.
Once the light level over the relevant LDR sets is restored, the op-amps again
become dormant and switch off their outputs and also the motor.

20. 19
Chapter 4
In this chapter, we will present the features advantages and disadvantages of the
project.
4.1 Features:
 Actuators / output devices: gear motor and battery status.
 Power source: Battery or router trans
 Controller: LM324 Comparator with two LDR's
 Sensors / input devices: LDR senor / voltage sensing
 Target environment: Outdoor (Just a prototype with uncover board)
4.2 Advantages:
 The solar energy can be reused as it is non-renewable resource.
 This also saves money as there is no need to pay for energy used (excluding
the initial setup cost)
 Helps in maximizing the solar energy absorption by continuously tracking the
sun.
 Solar trackers generate more electricity than their stationary counterparts due
to an increased direct exposure to solar rays.
 There are many different kinds of solar tracker, such as single-axis and dual-
axis trackers, which can help you find the perfect fit for your unique job site.
Installation size, local weather, degree of latitude, and electrical requirements
are all important considerations that can influence the type of solar tracker
that’s best for you.
 Solar trackers generate more electricity in roughly the same amount of space
needed for fixed tilt systems, making them ideal optimizing land usage[6]
4.3 Disadvantages:
 These panels can be used to power the traffic lights and streetlights
 These can be used in home to power the appliances using solar power.
 These can be used in industries as more energy can be saved by rotating the
panel.
 This motion takes place in response to the position of the sun during the
seasonal changes, therefore in contrast to the vertical movements; this
operation is very gradual and cannot be experienced daily [6].

21. 21
Chapter 5
5.1 The Result:
In this chapter, the result of testing the circuit shown:
Initially we didn't use solar panel instead of that we use a piece of wood just for
testing .The circuit is shown in Figure 5.1
Our circuit well done successfully and gotten a good result, the circuit follows
the light with a high sensitivity according of that the speed of motor was very
high that challenge us to solve that we must use microcontroller.
Figure 5.1 Result
5.2 Future Directions:
This system can further improved by following ways and effective suggestion.
The structure of the solar tracker can be made more light by using composite
materials. The tracking can be done more precisely by using servo motor
instead of gear motor. Here we have only vertical axis which can track the sun
by linear actuator mechanism and position setting, and the horizontal axis is set
and controlled manually. Therefore, we can fix another linear actuator at the
hinges of panel frame which can track the sun more efficient not only dawn to
dusk seasonal but also daily vise. Effective tracking can be done by
photoconductive cells for sensing the heat of the sun seasonally (means north
south). To avoid negative impacts of Voltage fluctuations a regulation system
should be installed before storing current and for direct usage. The system
should work more effectively when seasonal position adjustment are made

22. 21
properly. (mirrors) can be fit at the edges of the panel frame with calculated tilt
angels so that more sunlight can be reflected to the PV panel and more will be
the power output. Hourly and daily inspection is needed. It is effectively used
for battery charging and can be used for standby system.
5.3 Conclusion
Single Axis Sun Tracking Solar System model is developed by considering
given specification. The system is able to track and follow the Sun intensity in
order to get maxımum power at the output regardless motor speed. Besides,
low speed DC geared motor has been used for neglecting motor speed
parameter and therefore the system only focuses in tracking of Sun intensity.
The system can be applied in the residential area for alternative electricity
generation especially for non-critical and low power appliances.

23. 22
Chapter 6
References
[1] https://vishalnagarcool.blogspot.com/2019/01/single-axis-solar-tracking-system-
using.html
[2] http://solarflexrack.com/advantages-and-disadvantages-of-a-solar-tracker-
system/?fbclid=IwAR3m4oKbHHw2Lfg3uJeA1P54E-nOO4mvPygBRSlCts2gK6366kzxAuI0akI
[3] https://www.componentsinfo.com/bd140-pinout-equivalent-uses-
applications/?fbclid=IwAR3vzoZk0U9WPq1K96Ha4dan1lLHCMKexSFejSIkRG2YcufgZUjV8LXd
zWA
[4] https://www.theengineeringprojects.com/2017/06/introduction-to-
1n4148.html?fbclid=IwAR16nxiwmDZ6hLRjNLjei8NCF_PhYSH1FhZSXkHGKKhJaWxCYF20zyi08
2A
[5] http://www.resistorguide.com/variable-resistor/?fbclid=IwAR0KnAgzA25LH5mVHDk-
ItYZDBXSoctOeS5Td9AiH0hi5H6kGjhvX87lUOA
[6] http://solarflexrack.com/advantages-and-disadvantages-of-a-solar-tracker-
system/?fbclid=IwAR3m4oKbHHw2Lfg3uJeA1P54E-nOO4mvPygBRSlCts2gK6366kzxAuI0akI