Many changes have been made in this edition, first to the nomenclature
so that the book is in agreement with the International System of Units
(S. I. ) and secondly to the circuit diagrams so that they conform to B.
S. S. 3939. The book has been enlarged and now has 546 problems. Much
more emphasis has been given to semiconductor devices and transistor
circuits, additional topics and references for further reading have been
introduced, some of the original problems and solutions have been taken
out and several minor modifications and corrections have been made. It
could be argued that thermionic-valve circuits should not have been
mentioned since valves are no longer considered important by most
electronic designers except possibly for very high power or voltage
applications. Some of the original problems on valves and valve circuits
have been retained, however, for completeness because the material is
still present in many syllabuses and despite the advent and
prolification of solid-state devices in recent years the good
old-fashioned valve looks like being in existence for a long time. There
are still some topics readers may expect to find included which have had
to be omitted; others have had less space devoted to them than one would
have liked. A new feature of this edition is that some problems with
answers, given at the end of each chapter, are left as student exercises
so the solutions are not included. The author wishes to thank his
colleagues Professor P. N.
