Want to switch on circuit makers?

As someone who has always used Gordon Lancaster's Introduction to Fields and Circuits (1992) for teaching purposes, I approached the task of reviewing these books with great interest. It was immediately obvious that there would be an opportunity for a favourite rant, but whether to direct this against the authors or the publishers is unclear. These books all have their origins in the United States, which has a different system for domestic electrical supply and still uses units of measurement that have long been discarded elsewhere. If the texts are intended for an international audience, they should at least acknowledge that other systems and other units exist.

Although four texts are listed for consideration, they fall naturally into two groupings. The first three can be treated together. The fourth covers quite different concepts in circuits and will be discussed towards the end.

The questions to be addressed concern market and audience. The first two books are clearly university texts, but I am less certain about the nature of the third. The second book is particularly clear about its audience and does an excellent job of targeting the content.

I would like to offer special praise to Robert Boylestad. Almost alone, he provides a section that introduces SI units and even has a section titled "120V at 60Hz versus 220V at 50Hz". I like his overall approach and his use of the concept of energy storage to underpin his presentation. In an era where magnetics is omitted from many electrical engineering (EE) courses, I found his treatment of magnetic circuits quite refreshing. There was also a seamless transition from DC to AC circuits.

There were no great problems with the approaches adopted by Bruce Carlson, who has written a fine, serviceable text. It suffers from the fact that it lies right between one book that I really admired and one that I disliked. Carlson avoids an over-dependence on 120V at 60Hz before page 337, where I found his presentation on US domestic wiring circuits most interesting. I would be very happy to recommend this text to students.

I may be being unfair to Clayton Paul. What appear to have been quality problems in the book's production (it is cropped with inconsistent and very narrow margins) may have made me jaundiced. I found the level of mathematics to be quite demanding throughout, and I question whether the author is realistic about his target audience (he claims among other things that the text could be used to support a service course "to non-EEs such as mechanical engineers and civil engineers"). However, it was in the middle ground that I found the greatest problems with his book. Having introduced DC circuits in a reasonable manner, the author produces much confusion during the transition to AC circuits. He starts with energy-storage elements but, because of the approach that he has adopted to explain transformers, it is necessary to introduce sinusoidal excitation pages before he comes to a chapter devoted to the same topic. Within this chapter, students are confronted by Fourier series, complex numbers and phasors in quick and unrelenting succession. Some people may find it useful, but I would not recommend it to my students.

Any course on circuits and circuit theory must be supported by appropriate Cad tools, and all except the fourth book, by Reinhold Ludwig and Pavel Bretchko, include pSpice. They, Carlson and Paul, but not Boylestad, also include Matlab. This is the ninth edition of Boylestad, and one wonders why such an important package was omitted (although there is passing reference to Mathcad). Boylestad is unique among these texts in that many of the problems are also presented in C++. I also wonder why he has retained Basic from previous editions. This decision could raise objections from any computer scientists associated with EE/ECE courses.

When the dust has settled after this review, Boylestad will still be near my desk. If weight were a criterion then it would be a non-runner; also, his comments on the dangers due to fluorine gas in fluorescent lamps are somewhat suspect. Nevertheless, I feel comfortable with this book and its layout. So spoilt was I by the provision of interesting in-margin examples and biographical vignettes that I felt let down when there were none next to a section such as that on the Millman theorem. I hope that students will enjoy this book and they should be encouraged to retain it as an excellent source of reference for their future careers.

The other book that will stay on my desk is by Ludwig and Bretchko. Whereas the other books are concerned with DC circuits and AC circuits at relatively low frequencies, their book is devoted to circuits at RF frequencies. It is a welcome breath of fresh air, covering a topic which does not appear in many university courses but is nevertheless vital in an era dominated by high-frequency communications. The authors claim that there is a lack of books of this type, which is true. They claim that the starting requirement is first-year undergraduate electromagnetism, which is also true, but the mathematical requirements are perhaps a little more challenging than suggested. They start by introducing high-frequency skin effects in conductors and quickly move to the Smith chart, which they use as an educational tool. This is followed by excellent sections on networks and network transformations, on matching and biasing networks, and there are nine appendices. This is probably the first accessible text that shows students how to design microstrip circuits, and any student who thoroughly digests the content should have excellent prospects in the wireless communications jobs market. Matlab is used throughout as the Cad tool. Fifteen years ago, I had a problem when a project student wished to model the equivalent circuit of a microwave pin diode using Spice. Life would have been so much easier if Ludwig and Bretchko had been available at that time.

Donard de Cogan is reader in electronics, University of East Anglia.