include permanent-
magnetic, printed-circuit, and moving-coil (or shell) dc
servo motors. The rotor of a shell dc
servo motor consists of a cylindrical shell of copper or aluminum wire coils which rotate in a
magnetic field in the annular space between
magnetic pole pieces and a stationary iron core. The
servo motor features a field, which is provided by cast AlNiCo magnets whose
magnetic axis is radial.
Servo motors usually have two, four, or six poles. DC
servo motor characteristics include...
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