摘要 |
An improved electrical drive circuit for a reversible electric stepping motor of the type having a coil supplied with electrical pulses to cause step-by-step rotation of a magnetized rotor, where the rotor includes additional magnetic poles for locking the rotor between steps in a stable equilibrium located so as to reduce the energy of pulses required to produce normal forward rotation of the rotor. Forward rotation is produced by a switching circuit which periodically connects a voltage source and energy dissipating means in circuit with the coil for pre-determined time intervals in a forward switching cycle. The reverse rotation switching cycle includes one or more pulse portions in the forward rotation to pre-position the rotor for reversal. Preparatory to reversal, the reverse switching cycle applied to the motor coil includes a train of high frequency pulses which reduce the electromagnetic torque in the forward rotational direction and control coil current.
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