Book excerpt: Small electric motors are crucial to the manufacture of industrial robots, numerically controlled machines, and computer peripherals such as disk drives and printers. In this handbook, Dr. Kenjo considers two of the most important small motors, permanent-magnet and brushless DC motors, explaining how to select the most suitable motor for the the intended application and how to design the drive circuitry. The book provides clear descriptions of the basic machine structure, the constructional relationships between conventional and brushless DC machines, and the drive and control circuitry. Generously illustrated and easy-to-follow.