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. 22, 1998
Filed:
Jun. 07, 1995
Eugene T Mullin, Phoenixville, PA (US);
Clifford J Bader, West Chester, PA (US);
Lockheed Martin Corporation, Bethesda, MD (US);
Abstract
A system and method is disclosed for feedback velocity control of a D.C. motor. The system includes a motor (30) which is represented by its circuit equivalent--a series combination of an inductance (32), a resistor (34) and a back EMF source (36). The drive to the motor (30), supplied by a controller, is periodically inhibited by timing logic (22) and AND gate (20). Once the inductive transient decays via clamping diode (38) such that the motor current is zero, switch (40) is closed and the internally generated motor voltage is sampled by a capacitor (42). A/D converter (44) transforms the sampled value to a digital value and sends it to the controller. The controller compares it to a predetermined desired value then makes the necessary adjustments to the drive signal.