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:
May. 08, 1990
Filed:
Mar. 14, 1989
Pierre Roussel, Neuilly Sur Seine, FR;
Jaeger, Levallois-Perret, FR;
Abstract
The present invention provides a circuit for shaping ripple in the armature current of a D.C. motor. The circuit includes a phase-locked loop (100). In addition, the circuit preferably includes a back-e.m.f. circuit (300) suitable for generating a signal proportional to the back-e.m.f. of the motor and for controlling the frequency of the phase-locked loop (100) on the basis of the signal obtained in this way and/or the back-e.m.f. circuit (300) suitable for generating a signal proportional to the back-e.m.f. of the motor, a voltage controlled oscillator (500) controlled by the signal proportional to the back-e.m.f., and a switched capacitor filter (400) controlled by the output of the oscillator (500), the filter being connected upstream from the phase-locked loop (100).