project report electronic design analog electronics ee2110e

INTRODUCTION:1.1 Introduction: Light sensor alarm systems are widely used to detect changes in light levels andprovide an alert in response to those changes.. In this project, we will be

HANOI UNIVERSITY OF SCIENCE AND TECHNOLOGY

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PROJECT REPORT Electronic Design/Analog Electronics (EE2110E)

Class code: 136277

Students list:

Trương Tuấn Huy Student’s code: 20207159 Class TE-E2 K65.

Nguyễn Giang Nam Student’s code: 20207165 Class TE-E2 K65.

HANOI 2022.1 HANOI UNIVERSITY OF SCIENCE AND TECHNOLOGY

PROJECT REPORT Electronic Design/Analog Electronics (EE2110E)

Class code: 136277

Students list:

Trương Tuấn Huy Student’s code: 20207159 Class TE-E2 K65.

Nguyễn Giang Nam Student’s code: 20207165 Class TE-E2 K65.

HANOI 2022.1

CHAPTER 1 INTRODUCTION 2

1.1 Objective 2

1.2 Requirement 2

1.3 Circumstances 2

1.4 Expected Outcome 3

CHAPTER 2 COMPONENTS 4

2.1 Resistor 4

2.2 LEDs 4

2.3 IC7805 Voltage regulator 5

2.4 IC555 6

2.5 Transistor BC547 6

2.6 Variable resistor (Potentiometer) 7

2.7 Relay SRD-12VDC-SL-C 7

CHAPTER 3 BLOCK DIAGRAM 9

3.1 Component 9

3.2 Problem solving method 9

CHAPTER 4 CIRCUIT ANALYSIS 10

4.1 Circuit diagram 10

4.2 Working of the circuit 10

CHAPTER 5 TEST RUN AND CONCLUSION 12

5.1 Simulation 12

5.2 Real product 13

CHAPTER 6 FUTURE SCOPE 14

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CHAPTER 1 INTRODUCTION:

1.1 Introduction:

Light sensor alarm systems are widely used to detect changes in light levels and provide an alert in response to those changes In this project, we will be designing a light sensor alarm system using a photoresistor to detect changes in light levels The system will be designed to trigger an alarm when the light to a tree is not available, providing a reliable means of detecting and responding to changes in light

The system will consist of a photoresistor that will be connected to a simple circuit that includes a resistor and an alarm The photoresistor will act as a variable resistor, changing its resistance depending on the amount of light it detects When the light level falls below a certain threshold, the resistance of the photoresistor will increase, triggering the alarm

The alarm can take different forms, such as a loudspeaker, flashing lights, or a notification sent to a smartphone or other device The goal of the system is to provide a simple and effective means of detecting changes in light levels and alerting the user when the light to their tree is not available By doing so, the system can help ensure that the tree remains properly illuminated, even in the absence of natural light

1.2 Objective:

The objective of this project is to design and build a light sensor alarm system that will detect changes in light levels and trigger an alarm when the light to a tree is not available The system will use a photoresistor to detect changes in light levels and will be designed to be simple, reliable, and effective The alarm will be triggered when the light level falls below a predetermined threshold, ensuring that the tree remains properly illuminated at all times The project will demonstrate an understanding of basic electronic circuits and sensors, as well as provide a practical solution to the problem of ensuring proper lighting for outdoor trees

We will simulate the circuit using Proteus program

1.3 Requirements of project:

In fact, in order to apply this circuit to detect the ability to light through of the led grow light, this circuit also has many uncertainties such as cost, components

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and weather conditions So the requirement is to make a circuit that is not only good in price, but also works stably in all weather conditions

Products made must be applied in good practice In addition, it is also necessary

to ensure the aesthetics of the product

Stable operation when the source changes

The light must turn off at dawn and turn on automatically when the light intensity drops to a certain extent High sensitivity and stability The circuit is simple and easy to customize

The input signal is a light signal, namely the light hitting the photoresistor This signal can change gradually over time (if it's sunlight) or suddenly (if it's artificial light) The output signal is sound signal form buzzer Non-functional requirements Compact, lifespan 1.5-2 years Cheap price (about 60,000 VND)

1.4 Expected outcomes of project:

Our project can use the light sensor circuit to serve the purpose of lighting, here are some typical products: Light sensor alarm systems are widely used in farming to detect changes in light levels that ensures plants grow gradually Besides, our circuit can be also used in security system to recognize the movement at night which cause the change in light The above products mostly use rechargeable batteries or solar energy, so the lifespan is not high, and it takes time to charge, so making a light sensor circuit using direct power on the power network is quite convenient and has a good lifespan, saving time, no need to charge

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CHAPTER 2 OVERALL DESIGN

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OP-AMP IC AND TRANSISTOR

ACTIVE AND RESET IC PHOTORESISTOR

BUZZER AND BUTTON

POWER SOURCE LIGHT

SOURCE

CHAPTER 3 CIRCUIT DESIGN

For this light sensor alarm system, a photoresistor and a buzzer have been chosen as the primary components A photoresistor is a simple, inexpensive, and effective type of light sensor that changes its resistance in response to changes

in light levels This makes it an ideal choice for detecting changes in light levels and triggering an alarm when the light falls below a certain threshold The buzzer, on the other hand, is a compact and easy-to-use component that provides

an audible alert when triggered This makes it a suitable choice for alerting the user when the light to their tree is not available Additionally, buzzers are widely available, easy to interface with, and can be powered by a variety of sources, making them a versatile component for many different types of projects By choosing a photoresistor and a buzzer for this light sensor alarm system, we can create a simple and effective solution for ensuring proper lighting for outdoor trees So we decided to choose a LDR and HXD buzzer

 Choose the source:

The HDX buzzer chosen for this light sensor alarm system has a specified voltage range of 4V to 8V, which means that it requires a voltage within this range to operate effectively However, in order to ensure that the buzzer has enough voltage to operate reliably and with sufficient volume, a 9V source has been selected for the system While a voltage outside of the specified range may cause damage to the buzzer or reduce its lifespan, in this case, the 9V source provides a small margin of safety while still falling within the buzzer's recommended operating range Additionally, 9V batteries are widely available,

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easy to use, and relatively inexpensive, making them a convenient choice for portable or standalone projects like this one By choosing a 9V source for the HDX buzzer, we can provide the system with the necessary voltage to operate effectively while still maintaining a reasonable level of safety and convenience

 Choose an OP AMP:

An op amp IC358 has been chosen for this light sensor alarm system to control the flow of current and ensure that the buzzer is only activated when the photoresistor detects a certain level of light Op amps are highly versatile and widely used electronic components that can be configured in a variety of ways

to perform different functions In this system, the op amp is used as a comparator, comparing the voltage output of the photoresistor with a reference voltage set by a voltage divider circuit When the voltage output of the photoresistor falls below the reference voltage, the op amp output goes high, allowing current to flow to the buzzer and triggering the alarm Conversely, when the voltage output of the photoresistor is above the reference voltage, the

op amp output remains low, preventing current from flowing to the buzzer and ensuring that the alarm is not triggered By using an op amp as a comparator in this way, we can create a reliable and precise control mechanism for the light sensor alarm system

 Choose a transistor:

1 Voltage and current requirements: The BC547BP transistor can handle a maximum voltage of 45V and a maximum current of 100mA, which should be sufficient for many low-power circuits

2 Gain: The BC547BP transistor has a typical beta (h ) value of 200, whichfe means it can provide a significant gain to the signal being amplified This could be useful in circuits that require amplification, such as audio amplifiers or oscillator circuits

3 Cost and availability: The BC547BP is a widely available and affordable transistor, making it a popular choice for many hobbyists and DIY electronics projects

4 Other characteristics: The BC547BP transistor is a general-purpose NPN transistor, which makes it suitable for a wide range of applications It also has a low noise level and a fast switching speed, which could be beneficial in certain circuits

To calculate the parameters of the BC547BP transistor in your circuit, we use the following formulas:

Emitter-Base voltage (Vbe):Vbe = V - 0.7Vbb

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Where 0.7V is the threshold voltage of the Emitter-Base junction.

With a value of V = 9V, we have:bb

Vbe = 9V - 0.7V = 8.3V

Emitter-Base current (Ib):

Ib = (V - V ) / Rbb be b

With a value of V = 8.3V and R = 220Ω, we have:be b

Ib = (9V - 8.3V) / 220Ω = 3.1mA

Collector-Base current (Ic):

Ic = β x Ib

Where β is the current gain factor of the BC547BP transistor

According to the datasheet of BC547BP, the average calculated value of β is about 200 However, this value may fluctuate depending on each specific transistor Therefore, to accurately calculate I , you need to determine thec specific β value of the transistor in your circuit

Assuming you have determined the specific β value of the transistor in your circuit to be 150, we have:

Ic = 150 x 3.1mA = 465mA

Collector-Emitter voltage (Vce):

Vce = V - (I x R )cc c c

With a value of V = 9V, I = 465mA, and R = 10,000Ω, we have:cc c c

Vce = 9V - (465mA x 10,000Ω) = 3.5V

 Choose NE555

The NE555 is a popular integrated circuit that is widely used as a timer or oscillator in electronic circuits In our circuit, we needed a component that could reset the buzzer without the need to unplug the power source The NE555 provides a convenient solution to this problem as it can be configured in a variety of ways to provide a timing function, including a one-shot or monostable mode By using the NE555 as a reset switch, we can ensure that the buzzer is reset and ready to sound again without interrupting the power source

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Additionally, the NE555 is a low-cost and widely available component, making

it an ideal choice for our circuit

CHAPTER 4: COMPONENTS

4.1) Photoresistor:

_Photoresistor: is used to sense the presence of light.

_Photoresistor is an electronic component made of a special substance whose

resistance changes and decreases with the level of light It is a linear, non-ohmic resistance

Photoresistor is used as a light-sensitive sensor in detector circuits, for example

in light meters when taking pictures, in circuits that determine the light and dark levels of the environment to activate automatic lighting switches

Photoresistor is made of high impedance semiconductor and no junction In the dark, photoresistors have resistances up to several (MΩ) When there is light, the resistance drops to a few hundred (Ω) The operation of photoresistors is based on the photoelectric effect in the mass of matter When a photon with enough energy hits it, it knocks an electron out of the molecule, becomes free in the mass, and makes the semiconductor a conductor The degree of electrical conductivity depends on the number of photons absorbed

Depending on the semiconductor, the photoresistor reacts differently to different photon wavelengths Photoresistor reacts later than photodiodes, about 10ms, so

it avoids rapid changes of light source

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4.2) Op - Amp IC LM358:

_Op-Amp IC is used to amplify the signal from the LDR

_An operational amplifier is a DC-coupled high gain electronic voltage amplifier It is a small chip which has 8 pins An operational amplifier IC is used as a comparator which compares the two signals, the inverting and non-inverting signal LM358 is a dual-channel operational amplifier It consists of two independent, high-gain, frequency-compensated operational amplifier To activate the IC, we connect the power source with the Vcc and GND pin Then,

we provide two input voltage to the op-amp for comparision

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4.3) Timer IC NE555:

IC 555 is monolithic timing circuit that gives precise and highly stable delays

of time or oscillation This IC can be used for where the temperature ranges from 0° to 70°C The main function of this IC is to generate an accurate timing pulse In the monostable mode, the delay of this IC is controlled by the external components like a resistor and capacitor In the astable mode, both the duty cycle and frequency are controlled by two external resistors and one capacitor

In this project, we use it in the bi-stable mode The circuit produces 2-stable state signals which are low and states The o/p signals of low and high state signals are controlled by reset and activate the i/p pins, not by charging and discharging of capacitors If a low logic signal is given to active pin, then the o/p of the IC circuit goes to high level If the low logic signal is given to the RST pin, then the o/p of the circuit goes to the low level

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4.4) NPN TRANSISTOR BC547

_A transistor is a semiconductor device accustomed to amplify or switch electrical signals and power It is composed of semiconductor material, typically with a minimum of 3 terminals for connection to an electronic circuit A voltage

or current applied to 1 pair of the transistor's terminals controls the current through another pair of terminals Because the controlled output power can be over the controlling input power, a transistor can amplify a signal

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_N-P-N Transistor: It consists of one p-type material that is present between two n-type materials N-P-N transistor is used to amplify weak signals to strong signals In NPN transistor, the electrons move from the emitter to collector region resulting in the formation of current in the transistor This transistor is widely used in the circuit

BC 547 has three terminals: emitter, collector and base It has two operation status: forward bias and reverse bias In the status of the forward bias, the current can pass when the collector and emitter are connected In the status of

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