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. 12, 2005
Filed:
Jul. 28, 2003
Applicants:
David Coutu, East Hampton, CT (US);
Robert A. Fournier, Newington, CT (US);
Inventors:
David Coutu, East Hampton, CT (US);
Robert A. Fournier, Newington, CT (US);
Assignee:
IMS Inc., Marlborough, CT (US);
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
G05B019/40 ;
U.S. Cl.
CPC ...
Abstract
The current in each phase of a multi-phase step motor is monitored and the excess phase current above the set point current, as required on a cycle-by-cycle PWM basis, is reduced thereby bringing each phase current down to the set point. The PWM frequency is automatically adjusted to maintain a minimum number of PWM edges within a portion of the current waveform. A maximum charge/discharge time is specified as a percentage of the PWM period. These provide an accurate independent current control within each phase of a multiphase step motor.