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BOOKSHELF Circuit analysis using a computer PC-Assisted Linear Circuit Analysis & Drawing, by Ian Sin­clair. Published 1993 by Butterworth-Heinemann Ltd (Newnes), Oxford, England. 279 pages, soft covers, 190 x 246mm. ISBN 0 7506 1662 8. Price $49.95. With all the circuit analysis programs now available for computers, it is not surprising that books relating to the topic are now being produced. This one is written to complement a circuit analysis program called “Aciran” which has been created by the author and which is available only from him. While that may seem to be a drawback, it appears that the functions of Aciran as a program are quite similar to a number of analysis programs such as Spice. This means that the book can be read in the general sense and the author makes it clear in the text where there are particular circuits which have performance which cannot be fully analysed by the Aciran software. Perhaps the most useful application of the text will be to the novice who is trying to decide whether or not to purchase circuit analysis software. Some design engineers do not like circuit analysis programs and are inclined to the view that such analysis will give rise to a “blinkered” approach to design, with the result that less innovation will occur. On the other hand, many circuit designs do call for a systematic analysis to be made in order to guarantee that they will perform as intended. Such analyses can be tedious and very time-consuming although some engineers have streamlined the process for their particular work by storing all the formulas in a programmable calculator or have transferred the formulas to a program written in Basic or C. In effect, they have written their own programs to do the job so that a painful and often boring job becomes a matter of routine. That still leaves wide applications for circuit analysis programs and it is up to the designer or engineer to decide whether to adopt a specialist one-off approach or take the gener­al approach with circuit analysis software. In practice, it seems that some designers love analysis programs and others hate ‘em. So be it. Either way, this text features lots of sample gain vs frequency and phase plots for many circuits and these will be of great use to novice designers in showing what this sort of software can do. We should point out that the book does assume that the reader has a good knowledge of AC circuit theory, as well as active circuitry design procedures involving transistors, FETs and op amps. Such know­ledge will be necessary in order to fully understand the gain and phase plots. As far as the contents are concerned, the book begins with a few pages on the principles of circuit analysis and then talks about computer basics, backing up, copying files and so on. Chapter 2 is entitled “Aciran In Action” and talks about the specific analysis program listed above, with respect to passive circuits. However, it is quite general in nature and applicable to most circuit analysis software. Chapter 3 continues with passive circuits while Chapter 4 moves on to active circuits and features transistors and FETs. Aciran handles these active components in a similar way to other analysis software except that it does not have a library of common transistors – the user has to tell the program the specific parameters before circuit analysis can proceed. Chapter 5 moves on to operational amplifier ICs and here the Aciran program comes with a library that encompasses a number of “bog standard” op amps (read: old and outmoded ones that nobody wants to use any more), such as 5532, 5534, TL084 and 741 but misses out on more modern, desirable and capable op amps. In the latter cases, the user is expected to provide the following parameters: input impedance, output impedance, open loop gain, gain bandwidth product and open loop gain tolerance (%). Surpris­ingly, slew rate is ignored and the author makes the comment that “the slew rate limitations of operational amplifiers should be remembered if you are concerned with high frequency waveforms at the higher amplitude levels.” I should think so too! Chapter 6 is entitled “Last Lap” and deals with resonant lines, open and shorted lines and imperfect components. It also has notes on PSPICE, the acknowledged standard amongst circuit analysis software. Chapters 7, 9 & 10 then deal with Autosketch, a more or less standard circuit drafting software. The treatment is fairly thorough but I am not sure that it is appropriate in this text since it appears to be majoring on circuit analysis – even the title and the cover design emphasises this. In conclusion, this text is well written and generally on target. However it would appear to have a fairly limited appeal, especially if you don’t intend purchasing the author’s software. If you wish to purchase the book, it is available from Butterworth-Heine­ mann, 271-273 Lane Cove Rd, North Ryde, NSW 2113. Phone (02) 335 4444. SC (L.D.S.) March 1994  71