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. 21, 1985
Filed:
Dec. 03, 1981
Applicant:
Inventor:
Makoto Ueda, Tokyo, JP;
Assignee:
Seiko Instruments & Electronics Ltd., Tokyo, JP;
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
G04B / ; G04C / ; G05B / ;
U.S. Cl.
CPC ...
318696 ; 368 86 ; 368218 ;
Abstract
A driving device of a stepping motor comprises a driver/detector circuit for detecting whether a rotor has rotated or not by comparing a voltage induced across a driving coil by the free oscillation of the rotor with a reference voltage after a driving pulse is cut off and a control circuit automatically varies the pulse width of the driving pulse in response to an output of the driver/detector circuit. The control circuit includes circuitry for lowering the reference voltage when the pulse width of the driving pulse is lengthened thereby enabling use of a wider range of driving pulse widths than would otherwise be possible.