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:
Apr. 27, 1993
Filed:
May. 03, 1991
Applicant:
Inventor:
Michel Burri, Gd-Saconnex, CH;
Assignee:
Motorola, Inc., Schaumburg, IL (US);
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
G05B / ;
U.S. Cl.
CPC ...
318685 ; 318696 ;
Abstract
A driver for a stepper motor including means (Q45, 45, 47, 402) for sampling the current in a motor winding (43) at an instant determined by means (401, 400)for generating a predetermined delay following winding commutation. The sample is compared with winding current by a comparator (403) the output of which is stored at a subsequent instant in a flip-flop (416) to provide an output (42). Current generated within the windings due to rotor motion provide a difference in output when the motor is running or blocked. The invention provides a solution to the problem of motion detection of a stepper motor without recourse to a positional sensor.