Electronics and Electrical Symbols.pdf

Electronics and Electrical Symbols Electronics Engineering Department 1 Electrical Wire Electrical Wire Connected Wires Not Connect Wires Electronics Engineering Department 2 Voltage, V Voltage is defined as energy per unit of...

Electronics and Electrical Symbols Electronics Engineering Department 1 Electrical Wire Electrical Wire Connected Wires Not Connect Wires Electronics Engineering Department 2 Voltage, V Voltage is defined as energy per unit of charge. Current, A Electrical current is the rate of flow of charge. Resistance, Ω Resistance is the opposition to current. Electronics Engineering Department 3 Voltage Source A voltage source provides electrical energy or electromotive force (emf), more commonly known as voltage. DC Voltage Source AC Voltage Source Electronics Engineering Department 4 Current Source An ideal current source can provide a constant current in any load. Just as in the case of a voltage source, the ideal current source does not exist but can be approximated in practice. Electronics Engineering Department 5 Resistors Components that are specifically designed to have a certain amount of resistance are called resistors. The principal applications of resistors are to limit current, divide voltage, and, in certain cases, generate heat. Resistor Electronics Engineering Department 6 Resistor Color Code Electronics Engineering Department 7 Types of Resistors Variable Resistors Variable Resistance Sensors Variable resistors are designed so Physical quantity alters the that their resistance values can electrical resistance be changed easily. Thermistor Photoconductive Strain Gauges Cell Potentiometer Rheostat change resistance as change resistance change resistance as a function of when a force is Used to divide Used to control a function of light temperature applied to them voltage current Electronics Engineering Department 8 Switches Commonly used for controlling the opening or closing of circuits SPST SPDT DPST DPDT NOPB NCPB Single-pole rotary (6-position) Electronics Engineering Department 9 Single Pole Single Throw (SPST) switch controls a single circuit. Single Pole Double Throw (SPDT) switch has a single pole and two different switch output options. The Double-pole–single-throw (DPST) switch permits simultaneous opening or closing of two sets of contacts. The Double-pole–double-throw (DPDT) switch provides connection from one set of contacts to either of two other sets. In the normally open push-button switch (NOPB), the connection is made between two contacts when the button is depressed, and the connection is broken when the button is released. In the normally closed push-button switch (NCPB), the connection between the two contacts is broken when the button is depressed. In a rotary switch, a knob is turned to make a connection between one contact and any one of several others Electronics Engineering Department 10 Protective Devices FUSES and CIRCUIT BREAKERS are placed in the current path and are used to deliberately create an open circuit when the current exceeds a specified number of amperes due to a malfunction or other abnormal condition in a circuit. Fuse symbol Circuit breaker symbol Electronics Engineering Department 11 Ground The reference point in an electric circuit. Reference Ground Chassis Ground Alternate reference symbol Electronics Engineering Department 12 Capacitor A passive electrical component that stores electrical charge and has the property of capacitance. A capacitor is an electrical device constructed of two parallel conductive plates separated by an insulating material called the dielectric. Basic Capacitor Electrolytic Capacitor Variable Capacitor Electronics Engineering Department 13 Inductor An inductor is a passive electrical component, formed by a coil of wire, that exhibits the property of inductance. When a length of wire is formed into a coil, it becomes an inductor. Fixed Variable Air core Iron core Ferrite core Electronics Engineering Department 14 Diode A diode conducts current when it is forward-biased when the bias voltage exceeds the barrier potential. A diode prevents current when it is reverse biased at less than the breakdown voltage. Electronics Engineering Department 15 Special Purpose Diode Zener Diode The zener diode is designed for operation in the reverse breakdown region. Electronics Engineering Department 16 Special Purpose Diode Varactor Diode A varactor is basically a reverse-biased pn junction diode that utilizes the inherent capacitance of the depletion region. Electronics Engineering Department 17 Special Purpose Diode LED A light-emitting diode (LED) is a semiconductor device that emits light when an electric current flows through it. Electronics Engineering Department 18 Special Purpose Diode Photodiode A photodiode is a semiconductor device that convers photons (light) into electrical current.. Electronics Engineering Department 19 Special Purpose Diode Tunnel Diode A tunnel diode is a very heavily doped p-n junction diode. In a Tunnel diode electric current decreases as the applied voltage increases, and at high voltage, it works as an ordinary p-n junction diode. Electronics Engineering Department 20 Special Purpose Diode Schottky Diode The schottky diode is formed by the junction of a semiconductor with a metal, also known as hot-carrier diode. Electronics Engineering Department 21 Transistors A transistor is a semiconductor device that controls current between two terminals based on the current or voltage at a third terminal and is used for the amplification or switching of electrical signals. Bipolar Junction Transistor (BJT) Junction Field-Effect transistor (JFET) Electronics Engineering Department 22 Transistors A transistor is a semiconductor device that controls current between two terminals based on the current or voltage at a third terminal and is used for the amplification or switching of electrical signals. Metal Oxide Semiconductor Field Effect Transistor (MOSFET) Enhancement MOSFET (E-MOSFET) Depletion MOSFET (D-MOSFET) Electronics Engineering Department 23 Thysristors The device acts as a switch and remains off until the forward voltage reaches a certain value; then it turns on and conducts. Conduction continues until the current is reduced below a specified value. Light-Activated Shockley Diode Silicon-Controlled Rectifier (SCR) Silicon-Controlled Switch (SCS) Silicon-Controlled Rectifier (LASCR) Electronics Engineering Department 24 Thysristors The device acts as a switch and remains off until the forward voltage reaches a certain value; then it turns on and conducts. Conduction continues until the current is reduced below a specified value. Unijunction Transistor (UJT) DIAC TRIAC Programmable Unijunction Transistor (PUT) Electronics Engineering Department 25 Basic Measuring Instruments Electronics Engineering Department 26 References Electronics Fundamentals, Pearson New International Edition, 8th edition Electronic Devices, Conventional Current Version, Ninth Edition, Thomas L. Floyd Electronics Engineering Department 26