
312 Electric Motors and Drives
Plate 9.2 Brushless d.c. motors with 4-pole rare earth
permanent-magnet rotors. These motors are intended for servo-type
applications, and have integral Hall effect rotor position sensors.
(Photograph by courtesy of Evershed and Vignoles Ltd)
in the same way as a conventional d.c. motor (see Chapter 4).
Many brushless motors are used in demanding servo-type
applications, where they need to be integrated with digitally
controlled systems. For this sort of application, complete
digital control systems which provide for torque, speed and
position control are available.
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