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. 07, 1989
Filed:
Oct. 05, 1987
Melvin E Swanberg, Claremont, CA (US);
Xerox Corporation, Stamford, CT (US);
Abstract
This invention relates to a multi-phase printed circuit board (PCB) tachometer for accurate measurement of the rotational speed and direction of an electric motor. The multi-phase output not only provides rotation velocity in the form of the conventional a-c output signal, but also provides rotation direction information, in addition to providing a higher rotational resolution than conventional PCB tachometers. According to a first embodiment of the present invention, a multi 'winding', multi-phase PCB tachometer that uses a single multi-pole magnet is constructed by using double sided boards with plated through holes. In a second embodiment, a multi-phase tachometer configuration is disclosed in which the number of radial printed circuit traces and the number of pole magnets are not equal, whereby the individual voltages generated across each radial segment will not be in phase, and thus can provide rotational direction information as well as velocity information.