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:
Nov. 23, 1999
Filed:
Nov. 06, 1998
John J Kardash, Gilroy, CA (US);
Quantum Corporation, Milpitas, CA (US);
Abstract
A frequency detector for a PLL controller, the controller being for generating an output signal to control a motor driver electrically connected to a motor having multiple phase windings arranged as a stator and a rotor having a permanent magnet or a DC current excitation winding for rotating the rotor, the motor driver selectively establishing current paths through selected windings in response to said output signal, to provide maximum torque to the rotor based on the rotational position of the rotor relative to the windings, the frequency detector comprising a monitor for detecting a number of pulses in said output signal during a time period between a first and a second rotational position of the rotor relative to the windings and a governor for generating a frequency control signal as a function of said number of pulses, wherein the PLL controller generates said output signal at output frequencies selectively as a function of said frequency control signal, whereby the frequency detector minimizes a difference between the frequency of the output signal and a corresponding rotational frequency of the rotor.