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:
May. 13, 1986
Filed:
Sep. 13, 1984
Koushun Sun, Elgin, IL (US);
Motorola, Inc., Schaumburg, IL (US);
Abstract
A brushless direct current motor control system is disclosed in which a permanent magnet rotor induces voltages in phase windings and wherein these voltages are compared to a reference signal to provide for the proper cyclic and sequential energization of the motor drive phase windings. A protection circuit is utilized to couple a reference level, corresponding to the level about which the phase induced signals vary, as an input to the motor control circuit for effective comparison with the phase induced signals so as to provide for the proper sequencing of phase excitation. The protection circuit typically provides a substantially constant voltage drop between the reference level of the induced voltages and the input terminal of the motor control circuit with the protection circuit also preventing any excessively large magnitude voltages from being applied as an input to the motor control circuit. The input signal to the motor control circuit provided by the protection circuit also provides operative power to the motor control circuit.