Lectures 1 and 2: Welcome to IEE A practical introduction to Electrical, Computer and Systems, and Electric Power Engineering Concepts Beginning with Voltage, Current, Resistance, Power, & Diodes 18 November 201818 November 2018 Introduction to Engineering Electronics K. A. Connor

Introduction to Engineering Electronics Prof. K. A. Connor http://www.rpi.edu/~connor connor@rpi.edu Office: JEC 6010 Phone: 8552 Secretary: Audrey Hayner in JEC 6003 Info on WebCT – Go to http://webct.rpi.edu 18 November 201818 November 2018 Introduction to Engineering Electronics K. A. Connor

Introduction to Engineering Electronics Course Organization Lectures each Monday on a range of topics involving the use of electronics and other fundamental concepts in engineering, particularly in Electrical, Computer and Systems, and Electric Power Engineering 10-11 Labs Homework (Not very much) All work must be completed in a timely manner to pass. (S/U grade) 18 November 201818 November 2018 Introduction to Engineering Electronics K. A. Connor

Introduction to Engineering Electronics Requirements All lectures are mandatory Attendance is taken through a variety of activities Up to 2 unexcused absences are permitted All labs are mandatory Make up time is provided should a lab be missed Missed labs must be completed promptly. You cannot be more than one lab behind at any time. Signed rules statement is required Please read syllabus (online) for policy details 18 November 201818 November 2018 Introduction to Engineering Electronics K. A. Connor

Voltage, Current, Power and Resistance Fundamental concepts Voltage V volt Current I amp Power W watt Resistance R ohm V I 18 November 201818 November 2018 Introduction to Engineering Electronics K. A. Connor

Introduction to Engineering Electronics Voltage Voltage is defined as the amount of work done or the energy required (in joules) in moving a unit of positive charge (1 coulomb) from a lower potential to a higher potential. Voltage is also called potential difference (PD). When you measure voltage you must have two points to compare, one of them being the reference point. When measuring the voltage drop for a circuit component it is sometimes called measuring the potential across that component. 1 volt = 1 joule/coulomb 18 November 201818 November 2018 Introduction to Engineering Electronics K. A. Connor

Introduction to Engineering Electronics Voltage Voltage is analogous to pressure. A battery in an electrical circuit plays the same role as a pump in a water system. 18 November 201818 November 2018 Introduction to Engineering Electronics K. A. Connor

Introduction to Engineering Electronics Current Current is the amount of electric charge (coulombs) flowing past a specific point in a conductor over an interval of one second.  1 ampere = 1 coulomb/second Electron flow is from a lower potential (voltage) to a higher potential (voltage). 18 November 201818 November 2018 Introduction to Engineering Electronics K. A. Connor

Introduction to Engineering Electronics Current For historical reasons, current is conventionally thought to flow from the positive to the negative potential in a circuit. 18 November 201818 November 2018 Introduction to Engineering Electronics K. A. Connor

Introduction to Engineering Electronics Power Power is the rate at which energy is generated or dissipated in an electrical element. 1 watt = 1 joule/sec Generated Dissipated 18 November 201818 November 2018 Introduction to Engineering Electronics K. A. Connor

Introduction to Engineering Electronics Resistance Charges passing through any conducting medium collide with the material at an extremely high rate and, thus, experience friction. The rate at which energy is lost depends on the wire thickness (area), length and physical parameters like density and temperature as reflected through the resistivity 18 November 201818 November 2018 Introduction to Engineering Electronics K. A. Connor

Introduction to Engineering Electronics Circuit Diagram Water flow analogy is helpful, if not totally accurate 18 November 201818 November 2018 Introduction to Engineering Electronics K. A. Connor

Introduction to Engineering Electronics Basic Electrical Laws Ohm’s Law Kirchoff’s Voltage Law Kirchoff’s Current Law 18 November 201818 November 2018 Introduction to Engineering Electronics K. A. Connor

Introduction to Engineering Electronics Ohm’s Law Georg Ohm There is a simple linear relationship between voltage, current and resistance. 18 November 201818 November 2018 Introduction to Engineering Electronics K. A. Connor

Kirchoff’s Voltage Law (KVL) Gustav Kirchoff The sum of the voltage differences around a circuit is equal to zero. 18 November 201818 November 2018 Introduction to Engineering Electronics K. A. Connor

Kirchoff’s Current Law (KCL) Applying conservation of current. The sum of all the currents entering or exiting a node is equal to zero. 18 November 201818 November 2018 Introduction to Engineering Electronics K. A. Connor

Introduction to Engineering Electronics Conservation Laws Both the KVL and KCL are based on conservation laws. KVL conserves voltage KCL conserves current Other conservation laws we know about Conservation of energy Conservation of momentum A key to understanding any system is identifying the relevant conservation laws 18 November 201818 November 2018 Introduction to Engineering Electronics K. A. Connor

Series Combination of Resistors Resistors add in series 18 November 201818 November 2018 Introduction to Engineering Electronics K. A. Connor

Series Combination of Resistors The effect of resistors in series is additive. There is a corresponding voltage drop across each resistor. 18 November 201818 November 2018 Introduction to Engineering Electronics K. A. Connor

Parallel Combination of Resistors The reciprocal or inverse of resistors add in parallel. 18 November 201818 November 2018 Introduction to Engineering Electronics K. A. Connor

Parallel Combination of Resistors For resistors in parallel, the same voltage occurs across each resistor and more than one path exists for the current, which lowers the net resistance. 18 November 201818 November 2018 Introduction to Engineering Electronics K. A. Connor

Series Combination of Resistors KVL: Ohm’s Law: Solve for Ia: In General 18 November 201818 November 2018 Introduction to Engineering Electronics K. A. Connor

Parallel Combination of Resistors KCL: Ohm’s Law: In General: 18 November 201818 November 2018 Introduction to Engineering Electronics K. A. Connor

Combination of Resistors Series Parallel For two resistors, the second expression can be written as 18 November 201818 November 2018 Introduction to Engineering Electronics K. A. Connor

Combination of Resistors Adding resistors in series always results in a larger resistance than any of the individual resistors Adding resistors in parallel always results in a smaller resistance than any of the individual resistors 18 November 201818 November 2018 Introduction to Engineering Electronics K. A. Connor

Introduction to Engineering Electronics Diodes A diode can be considered to be an electrical one-way valve. They are made from a large variety of materials including silicon, germanium, gallium arsenide, silicon carbide … 18 November 201818 November 2018 Introduction to Engineering Electronics K. A. Connor

Introduction to Engineering Electronics Diodes In effect, diodes act like a flapper valve Note: this is the simplest possible model of a diode 18 November 201818 November 2018 Introduction to Engineering Electronics K. A. Connor

Introduction to Engineering Electronics Diodes For the flapper valve, a small positive pressure is required to open. Likewise, for a diode, a small positive voltage is required to turn it on. This voltage is like the voltage required to power some electrical device. It is used up turning the device on so the voltages at the two ends of the diode will differ. The voltage required to turn on a diode is typically around 0.6-0.8 volt for a standard silicon diode and a few volts for a light emitting diode (LED) 18 November 201818 November 2018 Introduction to Engineering Electronics K. A. Connor

Introduction to Engineering Electronics Diodes 10 volt sinusoidal voltage source Connect to a resistive load through a diode This combination is called a half-wave rectifier 18 November 201818 November 2018 Introduction to Engineering Electronics K. A. Connor

Introduction to Engineering Electronics Diodes Sinusoidal Voltage 18 November 201818 November 2018 Introduction to Engineering Electronics K. A. Connor

Introduction to Engineering Electronics Diodes Half-wave rectifier 18 November 201818 November 2018 Introduction to Engineering Electronics K. A. Connor

Introduction to Engineering Electronics 18 November 201818 November 2018 Introduction to Engineering Electronics K. A. Connor

Introduction to Engineering Electronics 18 November 201818 November 2018 Introduction to Engineering Electronics K. A. Connor

Introduction to Engineering Electronics At the junction, free electrons from the N-type material fill holes from the P-type material. This creates an insulating layer in the middle of the diode called the depletion zone. 18 November 201818 November 2018 Introduction to Engineering Electronics K. A. Connor

Introduction to Engineering Electronics 18 November 201818 November 2018 Introduction to Engineering Electronics K. A. Connor

Introduction to Engineering Electronics 18 November 201818 November 2018 Introduction to Engineering Electronics K. A. Connor

Diode V-I Characteristic For ideal diode, current flows only one way Real diode is close to ideal Ideal Diode 18 November 201818 November 2018 Introduction to Engineering Electronics K. A. Connor

Introduction to Engineering Electronics 18 November 201818 November 2018 Introduction to Engineering Electronics K. A. Connor

Where Will You See These Concepts Again? In later labs in this course V, I, R, Kirchoff’s Laws, Combining Resistors: ECSE-2010 Electric Circuits Diode and Transistor Theory and Electronic Design: ECSE-2050 Analog Electronics, ECSE-2060 Digital Electronics and ECSE-2210 Microelectronics Technology 18 November 201818 November 2018 Introduction to Engineering Electronics K. A. Connor