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:
Mar. 31, 2009
Filed:
Oct. 30, 2006
Rodney B. Washington, Raleigh, NC (US);
Rodney B. Washington, Raleigh, NC (US);
Square D Company, Palatine, IL (US);
Abstract
A DC motor phase detection algorithm that monitors the change in motor current to detect pulses in the current caused by the motor's commutator brushes crossing over the gap between rotor commutator segments as the motor shaft rotates. A pulse is generated each time a commutator brush breaks and then reconnects to a commutator segment. The algorithm detects and counts the pulses in order to determine the number of revolutions the shaft has rotated. The motor phase can then be used to determine the distance, rotational or linear, that the moving portion of the load attached to the motor has traveled. If the initial position of the moving portion of the device is known then the absolute position can be calculated.