A companion to Volume 6 ("Basic Electrotechnology for Engineers") this book covers more aspects of the theory of Electrotechnology. The syllabus is close to that of Electrical Engineering for Marine Engineer Cadets (Phase 3) of the Alternative Training Scheme and covers more fully the requirements of the DoT syllabus for Class 1 and Class 2 Marine Engineers. Students studying for the Extra First Class Engineers' Certificate will also find it of value. It anticipates future extensions of these syllabuses and deals with brushless AC generators, excitation systems for marine alternators, and semiconductor theory relating to the diode, transistor and the thyristor. Numerous fully-worked problems are included in the text as well as test examples and typical examination questions with solutions.