Switching Power Supply Design, 2nd Edition
Mathematically sufficient without being unnecessarily academic, this practical book's tutorial, how-to approach shows how even a novice can immediately design a complete switching power supply circuit.
TABLE OF CONTENTS Switching Power Supply Design, 2nd Edition
Chapter 3: Half- and Full-Bridge Converter Topologies
3.1 Introduction
Half- and full-bridge topologies subject their transistors in the off state to a voltage stress equal to the DC input voltage and not to twice that as do the push-pull, single-ended, and interleaved forward converter topologies. Thus the bridge topologies are used mainly in offline converters where twice the rectified DC would be more than the usual switching transistors could safely tolerate. Bridge topologies hence are almost always used where the nominal AC input voltage is 220 V or higher and frequently for 120 V AC.
An additional valuable feature of the bridge topologies is that primary leakage inductance spikes (Figs. 2.1, 2.10) are easily clamped to the DC supply bus and any energy stored in the leakage inductance is returned to the input bus instead of having to be dissipated in some resistive element.
3.2 Half-Bridge Converter Topology
3.2.1 Basic operation
Half-bridge converter topology is shown in Fig. 3.1. Its major advantage is that, just as the double-ended forward converter, it subjects the off transistor to only V dc and not twice that as do the push-pull and singled forward converter. It is thus widely used in equipment intended for the European market, where the AC input voltage is 220 V.
First consider the input rectifier and filter in Fig. 3.1. It is the universally used scheme when equipment is to be used with minimum changes either on 120-V-AC American or 220-V-AC European power. The circuit always yields roughly 320 V of rectified DC voltage ...
Copyright The McGraw-Hill Companies, Inc. 1998 under license agreement with Books24x7
