Book Review: Feedback Circuits and Op. Amps., 2nd Ed

Feedback Circuits and Op. Amps., 2nd ed: D. H. HORROCKS (Chapman and Hall 1990, 188pp., £10.95 paperback) This is the second edition of an already successful book, first published in 1983 by Van Nostrand Reinhold. This edition has numerous up-dates and revisions and includes a new chapter on 'further op. amp. applications' which, amongst other things, includes 'bootstrapping' (used to obtain higher input-impedance a.c. amplifiers), active-filter circuits, and precision-rectifier circuits. As a result, there are now many more op. amp. circuits in the basic 'toolkit' provided. One thing that puzzles me is why the 'differential' amplifier introduced in Chapter 3 has suddenly been renamed a 'difference' amplifier in Chapters 8 and 9; the latter description, however, does not appear in the index! Furthermore, this edition contains a bibliography (which the earlier one did not), and there is a new appendix on basic network analysis using 'j-notation', making this edition more selfcontained. There are numerous exercises and worked examples within the nine individual chapters, and, at the ends of eight of the chapters, there are numerical problems for the reader to try. The answers are given at the back of the book. These features, along with the technique of inserting notes, comments, references and relevant diagrams in the margin (a notable feature of all of the books in the series), make the book ideal for student self-study. It would be an ideal book for both degree and diploma students and their teachers. The book is well produced and easy to read and I would say that what was already a good book has been further improved. The extra 36 pages, no doubt, go some way to explaining the price increase! BRIAN M. SHAW, Division ofElectrical and Electronic Engineering, Hatfield Polytechnic