unit-1 Electronic Components.pdf

Introduction to Electronics Electronic Components play an important role in understanding the workings of electrical circuits. The application of electronic science is widely growing due to the large variety of electronic components. Most of the success in the electronic field over electrici...

Introduction to Electronics Electronic Components play an important role in understanding the workings of electrical circuits. The application of electronic science is widely growing due to the large variety of electronic components. Most of the success in the electronic field over electricity is due to various characteristics of components, like nonlinear performance, integration, cost, and size of the electronic components. If you observe any electronic circuit, there are only five varieties of Electronic Components. The circuit may appear complicated because several different components, but each type belongs to any of these five types. Electronic Components are classified into two groups Passive Components and active components. In this article, we will learn about the electronic components and applications of electronic components. Brief history of Electronic components The history of electronic components is a fascinating journey that traces the evolution of technology from simple devices to the complex systems we rely on today. Here’s a brief overview of the key milestones: 1. Early Beginnings (19th Century) Telegraph and Telephone (1830s-1870s): The telegraph, invented by Samuel Morse in 1837, was one of the earliest electrical devices. It used simple electrical circuits to send coded messages over long distances. This period also saw the invention of the telephone by Alexander Graham Bell in 1876, which further popularized the use of electrical circuits. Vacuum Tubes (1904): The first true electronic component was the vacuum tube, invented by John Ambrose Fleming. Vacuum tubes could amplify electrical signals and were used in radios, televisions, and early computers. Lee De Forest’s invention of the triode in 1906 allowed for signal amplification, laying the foundation for modern electronics. Brief history of Electronic components 2. The Advent of Semiconductors (1940s-1950s) The Transistor (1947): The invention of the transistor by John Bardeen, Walter Brattain, and William Shockley at Bell Labs revolutionized electronics. Transistors were smaller, more reliable, and consumed less power than vacuum tubes. They became the building blocks of all modern electronic devices. Diodes and Rectifiers: Alongside transistors, semiconductor diodes became crucial for rectifying and converting AC to DC. These components were essential in power supplies and signal processing. Brief history of Electronic components 3. The Integrated Circuit (IC) Era (1960s) Birth of the IC (1958-1960): Jack Kilby at Texas Instruments and Robert Noyce at Fairchild Semiconductor independently invented the integrated circuit (IC) in the late 1950s. ICs allowed multiple electronic components (transistors, resistors, capacitors) to be fabricated on a single piece of silicon, leading to the miniaturization of electronic devices. Microprocessors (1971): The invention of the microprocessor by Intel in 1971 marked the beginning of the modern computer era. The Intel 4004 was the first commercially available microprocessor, containing thousands of transistors on a single chip, and it revolutionized computing. Brief history of Electronic components 4. The Digital Revolution (1970s-1990s) Memory Chips: The development of RAM and ROM chips in the 1970s and 1980s allowed computers and other electronic devices to store and retrieve information quickly. This was critical for the advancement of personal computing. Optoelectronics: The development of LEDs (light-emitting diodes) and later lasers transformed telecommunications and displays. Fiber optics, enabled by these technologies, revolutionized data transmission. The Microcontroller (1980s): Microcontrollers, which integrate a CPU, memory, and I/O on a single chip, became essential in embedded systems. These small, versatile chips powered everything from household appliances to industrial machinery. Brief history of Electronic components 5. Modern Era and Beyond (2000s-Present) Nanotechnology: Advances in nanotechnology have led to the development of smaller, faster, and more efficient electronic components. This includes the ongoing development of quantum dots, graphene transistors, and other nanoscale materials. Power Electronics: Innovations in power electronics, such as MOSFETs and IGBTs, have improved the efficiency of power conversion and control, critical in renewable energy systems and electric vehicles. Wearable and Flexible Electronics: The development of flexible and wearable electronics has opened new frontiers in healthcare, fashion, and more, allowing for devices that can be integrated into clothing or worn directly on the body. Artificial Intelligence and IoT: With the rise of AI and the Internet of Things (IoT), electronic components like sensors, processors, and wireless modules have become crucial in connecting and automating devices across the globe. Conclusion From the invention of the vacuum tube to the rise of microprocessors and beyond, electronic components have continually evolved, driving the technological advances that define the modern world. Each generation of components has built upon the previous one, leading to the sophisticated, interconnected devices we use today. Passive Components 1. Passive Components Passive components are electronic components that do not require an external power source to operate. They can store or dissipate energy but cannot amplify or generate an electrical signal. Here are the key types of passive components: a. Resistors Function: Resistors limit the flow of electric current in a circuit. They convert electrical energy into heat, which is dissipated. Symbol: A zigzag line in circuit diagrams. Unit: Ohms (Ω). Applications: Used in voltage division, controlling current flow, and as pull- up or pull-down resistors in digital circuits. Passive Components b. Capacitors Function: Capacitors store electrical energy in an electric field between two conductive plates separated by an insulator (dielectric). Symbol: Two parallel lines (one of which may be curved) in circuit diagrams. Unit: Farads (F). Applications: Used in filtering, timing circuits, coupling and decoupling, and energy storage. Passive Components c. Inductors Function: Inductors store energy in a magnetic field when current flows through them. They oppose changes in current. Symbol: A series of loops or coils in circuit diagrams. Unit: Henrys (H). Applications: Used in filters, transformers, chokes, and energy storage. d. Transformers Function: Transformers transfer electrical energy between two or more circuits through electromagnetic induction. Symbol: Coils with lines representing the core in circuit diagrams. Applications: Used in power supplies to step up or step down voltage levels. Active components Definition: Active components are electronic components that can control the flow of electricity. These components require an external source of energy to operate and are capable of amplifying signals. Key Characteristics: Requires external power to operate (e.g., from a battery or power supply). Capable of amplification, meaning they can increase the power of a signal. Direction-sensitive, meaning they have polarity and need to be connected in a specific orientation. Active components Common Examples: Transistors: Used for amplification and switching. A transistor can amplify weak signals or switch electrical power on and off. Diodes: Allow current to flow in one direction only, used in rectification, signal demodulation, etc. Integrated Circuits (ICs): A combination of various electronic components, such as transistors, resistors, and capacitors, packed into a single chip, performing a specific function. Operational Amplifiers (Op-Amps): Used in a wide range of applications, including amplifiers, filters, and oscillators. Active components Applications: Signal amplification in audio systems. Power regulation in power supplies. Switching operations in digital circuits. Resistors: Introduction Resistors are one of the most fundamental components in electronics. They are used in almost every electronic circuit to limit current, divide voltages, and protect other components. Understanding the concept, specifications, and classifications of resistors is crucial for anyone studying electronics.  Concept of Resistors Definition: A resistor is a passive electronic component that opposes the flow of electric current in a circuit. The resistance offered by a resistor is measured in ohms (Ω). Key Functions: Current Limitation: Resistors control the amount of current flowing through a circuit, protecting sensitive components from excessive current. Voltage Division: Resistors can divide voltage in a circuit, providing different voltage levels from a single source. Heat Dissipation: Resistors convert electrical energy into heat, which is then dissipated into the environment. Signal Conditioning: Resistors are used in filtering and signal conditioning circuits to modify or clean up signals. Ohm’s Law: Ohm’s Law: The relationship between voltage (V), current (I), and resistance (R) is defined by Ohm’s Law: V=I×RV = I \times RV=I×R Where: VVV is the voltage across the resistor in volts (V), III is the current through the resistor in amperes (A), RRR is the resistance in ohms (Ω). Specifications of Resistors When selecting a resistor for a particular application, several key specifications must be considered: Resistance Value (R): Expressed in ohms (Ω), it determines how much the resistor will oppose the current. Available in a wide range of values from milliohms (mΩ) to megaohms (MΩ). Tolerance: Indicates the accuracy of the resistance value. Common tolerance values are ±1%, ±5%, ±10%, etc. A resistor with a ±5% tolerance could have an actual resistance value within 5% above or below its nominal value. 3. Power Rating Power Rating (P): Indicates how much power the resistor can safely dissipate without being damaged, expressed in watts (W). Common power ratings include 0.125W, 0.25W, 0.5W, 1W, 2W, etc. The power dissipated by a resistor is calculated by: P = I² x R Or P = V²/R Resistor Temperature Coefficient: Indicates how the resistance value changes with temperature, usually expressed in parts per million per degree Celsius (ppm/°C). A low temperature coefficient is preferred for precision applications Physical Size: Resistors come in various physical sizes, which are often related to their power rating. Resistor Type: The material and construction of the resistor can affect its performance, stability, and suitability for different applications. Classification of Resistors Resistors can be classified in several ways, including based on their composition, adjustability, and application. A. Based on Composition Carbon Composition Resistors: Made from a mixture of carbon powder and a binding material. Known for their ability to handle high energy pulses but have a higher noise level and less stability. Carbon Film Resistors: Made by depositing a thin layer of carbon onto a ceramic substrate. More stable and lower noise compared to carbon composition resistors. A. Based on Composition Metal Film Resistors: Made by depositing a thin layer of metal (often nickel-chromium) onto a ceramic substrate. Known for high stability, low noise, and precise tolerance. Wire-Wound Resistors: Made by winding a metal wire (usually nichrome) around a ceramic, plastic, or fiberglass core. Can handle high power and are used in high-current or high-temperature applications. Metal Oxide Resistors: Made from metal oxide film, offering better temperature stability and surge resistance compared to carbon film resistors. B. Based on Adjustability Fixed Resistors: Have a set resistance value that cannot be changed. Used in circuits where a specific, unchanging resistance is needed. Variable Resistors: Allow the resistance value to be adjusted. Examples include: 1. Potentiometers: Adjustable resistors used for tuning or adjusting voltage levels. 2. Rheostats: Variable resistors used to control current flow in a circuit. B. Based on Adjustability Thermistors: Temperature-sensitive resistors where resistance changes with temperature. NTC (Negative Temperature Coefficient): Resistance decreases as temperature increases. PTC (Positive Temperature Coefficient): Resistance increases as temperature increases. Photoresistors (LDR - Light Dependent Resistors): Resistors whose resistance decreases with increasing light intensity. Used in light-sensing circuits. C. Based on Application Precision Resistors: Designed for applications requiring precise resistance values with low tolerance (e.g., in measuring instruments). Power Resistors: Designed to dissipate large amounts of power, often used in power supplies and motor controls. Surge Resistors: Designed to absorb high-energy pulses, protecting other components from voltage spikes. Conclusion Resistors play a crucial role in controlling current, dividing voltage, and protecting circuits. Understanding their specifications and classifications helps in selecting the right resistor for a given application. Whether it's a simple circuit or a complex system, resistors are indispensable in the world of electronics. Resistor Introduction Resistors are essential components in electronic circuits, used to control the flow of electric current. They come in various types, but they can be broadly categorized into fixed resistors and variable resistors. Understanding these types, their applications, and how to identify them using color codes is crucial for anyone studying electronics at the diploma level. 1. Fixed Resistors Definition: Fixed resistors are resistors with a specific, unchanging resistance value. Once manufactured, their resistance cannot be altered or adjusted. Key Characteristics: Constant Resistance Value: The resistance does not change unless the resistor is damaged or subjected to extreme conditions. Reliability: These resistors are reliable for use in circuits where a consistent resistance is required. Types of Fixed Resistors: 1.Carbon Composition Resistors: 1. Made from a mixture of carbon dust and a binding material. 2. Typically used in older circuits or where high energy pulses are expected. 2.Carbon Film Resistors: 1. A thin carbon film is deposited on a ceramic substrate. 2. Used in general-purpose circuits due to their stability and low cost. 1.Metal Film Resistors: 1. A thin metal film (often nickel-chromium) is deposited on a ceramic substrate. 2. Known for high precision, stability, and low noise, making them ideal for precision applications. 2.Wire-Wound Resistors: 1. Made by winding a metal wire (usually nichrome) around a ceramic core. 2. Used in high-power applications where precise resistance is needed. 3.Metal Oxide Resistors: 1. Constructed using metal oxide film, offering better temperature stability than carbon film resistors. 2. Used in circuits requiring high stability and high temperature tolerance. Applications of Fixed Resistors: Voltage Dividers: Used to create a specific voltage from a higher voltage source. Current Limiting: Protect sensitive components by controlling the current flow in a circuit. Biasing Transistors: Provide the necessary voltage and current levels to operate transistors in amplifiers and other circuits. Signal Conditioning: Used in filters to shape the frequency response of signals in audio and communication circuits. Applications of Variable Resistors: Volume Control: Used in audio equipment to adjust the loudness of sound. Light Dimming: Rheostats are used to control the brightness of lights. Temperature Control: Thermistors are used in circuits that require temperature regulation, such as thermostats. Sensor Calibration: Trimpots are used to fine-tune sensors to achieve accurate readings. Concept of Capacitors Definition: A capacitor is a passive electronic component that stores electrical energy in an electric field, created between a pair of conductors on which equal but opposite electric charges have been placed. Key Characteristics: Capacitance (C): The ability of a capacitor to store charge per unit voltage, measured in farads (F). The formula for capacitance is: C=Q/V where Q is the charge in coulombs and V is voltage across the capacitor. Continue…. Energy Storage: Capacitors store energy in the electric field between their plates. The energy stored in a capacitor is given by: E = ½ CV² where E is is the energy in joules, C is capacitance in Farads, V is voltage in volts. Charge and Discharge: When connected to a power supply, capacitors store energy and charge up to the supply voltage. When disconnected, they can release this energy, providing power to the circuit for a short duration. Application : Filtering: Capacitors are used in power supplies to filter out AC ripple, ensuring smooth DC output. Timing Circuits: In combination with resistors, capacitors are used to create timing circuits, such as in oscillators and timers. Coupling and Decoupling: Capacitors block DC signals and allow AC signals to pass, making them useful in coupling and decoupling applications. Energy Storage: Capacitors can store energy for use in electronic flashes, power backup systems, and other high-energy applications. Classification of Capacitors : Capacitors can be classified based on their dielectric material, construction, and whether they are fixed or variable. A. Based on Dielectric Material 1. Ceramic Capacitors: Dielectric: Ceramic material. Characteristics: Small, non-polarized, with a wide range of capacitance values and voltage ratings. Applications: Used in high-frequency applications, bypassing, and filtering. 2. Electrolytic Capacitors: Dielectric: Electrolyte, usually aluminum or tantalum. Characteristics: High capacitance values, polarized, with large capacitance-to- volume ratio. Applications: Used in power supplies for smoothing and filtering applications. Classification of Capacitors : 3. Film Capacitors: Dielectric: Plastic film such as polyester, polypropylene, or polystyrene. Characteristics: Non-polarized, stable, and with low self-inductance. Applications: Used in audio circuits, RF applications, and timing circuits. 4. Paper Capacitors: Dielectric: Waxed paper. Characteristics: Large, with moderate capacitance and voltage ratings. Less common in modern electronics. Applications: Used in older circuits, now largely replaced by more reliable types. Classification of Capacitors : 5. Mica Capacitors: Dielectric: Mica. Characteristics: Highly stable, with low loss and high precision. Applications: Used in high-frequency RF circuits and precision applications. 6. Supercapacitors: Dielectric: Electrochemical. Characteristics: Extremely high capacitance, used for energy storage applications. Applications: Power backup systems, energy harvesting, and memory protection. B. Based on Construction Fixed Capacitors: Have a set capacitance value that does not change. Widely used in various electronic circuits. Variable Capacitors: Allow the capacitance to be adjusted manually. Used in tuning circuits, such as in radios. Specifications of Capacitors When selecting a capacitor for a specific application, various specifications need to be considered: Capacitance Value (C): The amount of charge a capacitor can store per unit voltage, measured in farads (F), microfarads (μF), nanofarads (nF) Working Voltage (WV): The maximum voltage that can be safely applied across the capacitor without breaking down the dielectric material. Exceeding this voltage can cause the capacitor to fail. Tolerance: Indicates how much the actual capacitance value can vary from the stated value, typically expressed as a percentage (e.g., ±5%, ±10%). Specifications of Capacitors Temperature Coefficient: Describes how the capacitance value changes with temperature, usually expressed in parts per million per degree Celsius (ppm/°C). Leakage Current: The small amount of current that flows through the dielectric material even when the capacitor is fully charged, more prominent in electrolytic capacitors. Equivalent Series Resistance (ESR): The resistance that appears in series with the capacitance, due to the leads and internal connections. Lower ESR is preferred in high-frequency applications. Lifetime/Endurance: Especially for electrolytic capacitors, the lifetime indicates how long the capacitor will function within its specifications under specific conditions (e.g., temperature and voltage). Fixed and Variable Capacitors Fixed Capacitors Definition: Fixed capacitors have a specific capacitance value that remains constant over time and cannot be adjusted. Common Types: Ceramic Capacitors: Used for general-purpose applications, including decoupling and bypassing. Electrolytic Capacitors: Used in power supply filtering, energy storage, and smoothing applications. Film Capacitors: Used in audio circuits, high-frequency applications, and precision timing circuits. Applications of Fixed Capacitor: Power Supply Smoothing: Electrolytic capacitors are used to filter out fluctuations in power supply circuits. Signal Coupling: Film capacitors are used to pass AC signals between stages of an amplifier while blocking DC. High-Frequency Circuits: Ceramic capacitors are commonly used in RF circuits for tuning and decoupling. Variable Capacitors Definition: Variable capacitors allow the capacitance to be adjusted manually, providing a range of capacitance values. Common Types: 1. Tuning Capacitors: Typically used in radio frequency circuits for tuning to different frequencies. Capacitance is varied by changing the overlapping area of the capacitor plates. 2. Trimmer Capacitors: Small, adjustable capacitors used for fine-tuning circuits. Used in RF circuits, oscillators, and filters. Applications: Radio Tuners: Variable capacitors are used in radios to tune into different frequencies by adjusting the capacitance in the LC circuit. Oscillators: Used in variable frequency oscillators (VFOs) to adjust the oscillation frequency. Fine-Tuning Circuits: Trimmer capacitors are used to adjust the performance of filters and RF circuits during circuit calibration. Inductors Definition: An inductor is a passive electrical component that stores energy in its magnetic field when electric current flows through it. The basic construction of an inductor consists of a coil of wire, often wound around a core made of ferromagnetic material like iron or ferrite. Key Characteristics: Inductance (L): The property of an inductor that opposes the change in current flowing through it, measured in henries (H). It is the ratio of the induced voltage to the rate of change of current: L = Vinduced/dI/dt Energy Storage: The energy stored in the magnetic field of an inductor is given by: E = ½ LI² where E is the energy in joules, L is the inductance in Henries, and I is the current in ampere Application Filters: Inductors are used in filters to block high-frequency signals while allowing low-frequency signals to pass. Chokes: Used in power supplies to smooth out AC ripple in DC circuits. Transformers: Inductors are the basic building blocks of transformers, which transfer electrical energy between circuits through electromagnetic induction. Faraday's Law of Electromagnetic Induction Faraday’s Law: Faraday’s law states that a change in the magnetic field within a closed loop of wire induces an electromotive force (EMF) in the wire. The induced EMF is proportional to the rate of change of the magnetic flux through the loop. Mathematical Expression: where: EMF is the induced electromotive force (in volts) ΦB is the magnetic flux (in webers, Wb) dΦB/dt is the rate of change of the magnetic flux. Lenz’s Law: Lenz’s law, which is incorporated in Faraday’s law, states that the direction of the induced EMF is such that it opposes the change in magnetic flux that produced it. This opposition is why the negative sign appears in the equation. Applications: Electric Generators: Convert mechanical energy into electrical energy using Faraday’s law. Transformers: Transfer electrical energy between two or more coils using electromagnetic induction. Inductive Sensors: Detect metal objects or measure magnetic fields based on the principle of electromagnetic induction. Self-Inductance Definition: Self-inductance is the property of a coil (or inductor) by which a change in current flowing through it induces an EMF in the coil itself. This induced EMF opposes the change in current, according to Lenz’s law. Formula: The self-induced EMF in a coil is given by: EMF = -L dI/dt where: L is the self-inductance of the coil (in henries), dI/dt is the rate of change of current (in amperes per second). Mutual Inductance Definition: Mutual inductance is the property by which a change in current in one coil induces an EMF in a neighboring coil. This is the fundamental principle behind transformers and coupled inductors. Formula: The mutual inductance M between two coils is given by: V2​=−M dI1​/dt ​ where: V2 is the induced EMF in the second coil (in volts), M is the mutual inductance between the two coils (in henries), dI1​/dt ​ is the rate of change of current in the first coil (in amperes per second). Inductor Specifications When selecting an inductor for a particular application, the following specifications must be considered: 1. Inductance (L): The primary specification, measured in henries (H), microhenries (μH), or millihenries (mH). It determines how much opposition the inductor will provide to changes in current. 2. Rated Current: The maximum current that the inductor can carry without overheating or saturating the core. Exceeding this current can cause the inductor to lose its inductance or become damaged. 3. DC Resistance (DCR): The resistance of the inductor's winding, measured in ohms (Ω). Lower DCR values are preferred for higher efficiency, as they reduce power loss. 4. Saturation Current: The current at which the core of the inductor saturates, leading to a rapid drop in inductance. Inductors should be chosen with a saturation current higher than the operating current. Inductor Specifications 5. Q Factor (Quality Factor): A measure of the inductor's efficiency, given by the ratio of its reactance to its resistance at a particular frequency. Higher Q factors indicate lower losses. 6. Core Material: The material of the core (air, ferrite, iron) affects the inductance, saturation current, and frequency response of the inductor. 7. Frequency Range: The range of frequencies over which the inductor maintains its inductance value. Some inductors are designed for high- frequency applications, while others are for low-frequency use. 8. Shielding: Inductors may have magnetic shielding to prevent interference with nearby components. This is important in densely packed circuits. Conclusion Inductors play a critical role in various electronic and electrical applications, from energy storage and filtering to transformers and inductive sensors. Understanding the concepts of inductance, Faraday's law, and the specifications of inductors is essential for designing and analyzing circuits effectively. Introduction Power supplies are essential components in electronic circuits, providing the necessary energy to operate various devices. Power supplies can be broadly classified into two types: Direct Current (DC) power supplies and Alternating Current (AC) power supplies. Understanding the analysis of these power supplies is crucial for students pursuing a diploma in electrical and electronics engineering. DC Power Supply Analysis Introduction to DC Power Supply Definition: A DC power supply provides a constant Direct Current (DC) output. It converts AC power from the mains into a stable DC voltage suitable for powering electronic circuits. Applications: Used in batteries, portable devices, and any circuit requiring a stable DC voltage. AC Power Supply Analysis Introduction to AC Power Supply Definition: An AC power supply delivers an Alternating Current (AC) output, where the current and voltage periodically reverse direction. The standard form of AC power is a sinusoidal waveform. Applications: Used in domestic appliances, industrial machinery, and any device requiring AC power.