The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Feb. 22, 1983
Filed:
Sep. 24, 1980
Paul Grand Chavin, Besancon, FR;
Timex Corporation, Waterbury, CT (US);
Abstract
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.