Paul 
Stepping Motors [PDF ebook] 
A guide to theory and practice

Stepping motor technology is well established and used for motion control, most notably for computer peripherals but also wherever digital control is employed. This book provides an introductory text which will enable the reader to both appreciate the essential characteristics of stepping motor systems and understand how these characteristics are being exploited in the continuing development of new motors, drives and controllers. A basic theoretical approach relating to the more significant aspects of performance is presented, although it is assumed throughout that the reader has no previous experience of electrical machines and is primarily interested in the applications of stepping motors. Paul Acarnley’s outstanding reference book is widely known and used, and this, the 4th edition, has been significantly updated to include many new applications that have emerged since the previous edition was published. Coverage includes: drive circuits, accurate load positioning, static torque characteristics, multi-step operation, torque/ speed characteristics, high-speed operation, open-loop control, closed-loop control and microprocessor-based stepping motor systems.