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:
Sep. 12, 2006
Filed:
Sep. 30, 2004
Jason P. Brenden, Woodbury, MN (US);
James A. Dahlberg, Eagan, MN (US);
Jason P. Brenden, Woodbury, MN (US);
James A. Dahlberg, Eagan, MN (US);
Agere Systems Inc., Allentown, PA (US);
Abstract
A control apparatus controls retraction of a device carried on a moveable member actuated by an electric motor. The control apparatus includes a measuring circuit with an output during a measuring phase including a back electromotive force (back EMF) from the electric motor plus a measuring circuit offset voltage. The control apparatus also includes an offset removing circuit connected to the output of the measuring circuit. The back EMF from the electric motor is provided at the output of the offset removing circuit. A driver circuit is connected to terminals of the electric motor for providing the electric motor with a drive current during a driving phase with a magnitude based on the back EMF from the electric motor.