AC to DC project

CONTENTS CHAPTER ONE 3 1 Introduction to power electronic switching devices 3 1.1 Classifications of Power Switches 4 1.1.1 Uncontrolled switch 5 1.1.2 Semi-controlled switch 5 1.1.3 Controlled switch 5 CHAPTER TWO 6 2 Uncontrolled Switches 6 2.1 Introduction to Diodes 6 2.1.1 Characteristics of diode 6 2.1.2 Switching capabilities of diode 8 2.2 Power Diode Types 9 2.2.1 General-purpose diodes 10 2.2.2 Fast-recovery diodes 11 2.2.3 Applications of Fast-recovery diodes 12 2.2.4 Schottky diode 13 2.2.5 Applications of Schottky diodes 15 CHAPTER THREE 16 3 Semi-controlled switch 16 3.1 Silicon-Controlled Rectifier (SCR) 16 3.1.1 Constructional details 17 3.1.2 Equivalent Circuit of SCR 17 3.1.3 V-I Characteristics of SCR 18 3.1.4 Applications of SCR 19 3.2 Gate turn-off thyristors (GTO) 19 3.2.1 GTO operating principle 20 3.2.2 V-I Characteristics of Gate Turn-Off Thyristor 21 3.2.3 Gate Turn-Off Thyristor Applications 22 3.3 MOS – Controlled Thyristor (MCT) 22 3.3.1 The equivalent circuit of the MCT 23 3.3.2 Advantages of MCT 24 CHAPTER FOUR 25 4 Controlled switching devices 25 4.1 The Bipolar Junction Transistor as a switch 25 4.2 The Metal Oxide Semiconductor Field Effect Transistor 27 4.3 The Insulated Gate Bipolar Transistor 28 5 References 31

2022

This document does not claim any originality and cannot be used as a substitute for prescribed textbooks. The information presented here is merely a collection by the teacher for his respective teaching assignments. Various sources as mentioned at the end of the document as well as freely available material from internet were consulted for preparing this document. The ownership of the information lies with the respective authors or institutions. 2.9 A.C.through Series R-L-C Circuit This is a general series a.c. circuit. Fig. 2.17 shows R, L and C connected in series across a supply voltage V (r.m.s.). The resulting circuit current is I (r.m.s.

COMPEL - The international journal for computation and mathematics in electrical and electronic engineering, 2020

Purpose This work is intended to historically commemorate the one hundredth anniversary of the invention of a new type of electronic circuit, referred to in 1919 by Abraham and Bloch as a multivibrator and by Eccles and Jordan as a trigger relay (later known as a flip-flop). Design/methodology/approach The author also considers the circuit-technical side of this new type of circuit, considering the technological change as well as the mathematical concepts developed in the context of the analysis of the circuit. Findings The multivibrator resulted in a “circuit shape” which became one of the most applied nonlinear circuits in electronics. It is shown that at the beginning the multivibrator as well as the flip-flop circuits were used because their interesting properties in the frequency domain. Originality/value Therefore, it is a very interesting subject to consider the history of the multivibrator as electronic circuits in different technologies including tube, transistors and integ...

IOP Conference Series: Materials Science and Engineering, 2017

The paper presents a continuous voltage inverter-AC (12V / 230V) made with IGBT and two-stage voltage transformer. The sequence control transistors is achieved using a ring counter whose clock signal is obtained with a monostable circuit LM 555. The frequency of the clock signal can be adjustment with a potentiometer that modifies the charging current of the capacitor which causes constant monostable circuit time. Command sequence consists of 8 intervals of which 6 are assigned to command four transistors and two for the period break at the beginning and end of the sequence control. To obtain an alternation consisting of two different voltage level, two transistors will be comanded, connected to different windings of the transformer and the one connected to the winding providing lower voltage must be comanded twice. The output of the numerator goes through an inverter type MOS and a current amplifier with bipolar transistor.To achieve galvanic separation, an optocoupler will be used for each IGBT transistor, while protection is achieved with resistance and diode circuit. At the end there is connected an LC filter for smoothing voltage variations.