ข้อมูลทรัพยากร

เนื้อหาย่อ : This book is intended for a first course in electric machines and transformers. The level of advanced mathematics has been kept to a minimum, and the em- phasis is on phenomena and physical characteristics of machines. Their quan- titative evaluations are made only in terms of simple mathematics, not beyond the high school level. However, concepts such as differentiation and integration are used rather loosely and may be skipped by the uninitiated without a loss of continuity. Throughout the text, numerous worked out examples have been used to illustrate the theories developed. In all instances, fundamentals are empha- sized and practical examples and data are presented wherever possible. It seems logical to start our discussions with magnetic circuits--an integral component of all electric machines. Thus, magnetic materials, their properties and circuit calculations are given in Chapter 1. Transformers-in particular power transformers-are discussed in Chapter 2. A number of photographs are included to illustrate the size, appearance, and components of certain trans- formers. Chapters 3, 4, and 5 respectively deal with dc machines, synchronous machines, and polyphase induction motors. A separate chapter--Chapter 6-is devoted to small (fractional horsepower) ac motors. Following the discussion of various motors in Chapters 3 through 6, electric drives and control of electric motors are presented in Chapter 7. Because solid-state controllers are now in common use in the industry, such controllers are presented in some detail.