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:
Sep. 15, 1992
Filed:
Jul. 25, 1991
Yukihisa Ishii, Wako, JP;
Shinichi Inagawa, Wako, JP;
Honda Giken Kogyo K.K., Tokyo, JP;
Abstract
A driving circuit for driving a stepping motor has a plurality of excitation coils, a plurality of excitation transistors for driving the excitation coils of the stepping motor, respectively, at least one chopping transistor for effecting chopping control of current flowing to the excitation coils, and a CPU for supplying at least one control signal to the at least one chopping transistor. High and low pulse duty factor detecting circuits detect whether the at least one control signal has a pulse duty factor thereof falling outside a predetermined range defined by predetermined upper and lower limit values. The CPU is responsive to outputs from the high and low pulse duty factor detecting circuits for interrupting the supply of current to the stepping motor when the latter detect that the pulse duty factor falls outside the predetermined range.