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:
Jun. 27, 1978
Filed:
Apr. 19, 1976
Benno Doemen, St. Georgen, DT;
Papst-Motoren KG, St. Georgen, DT;
Abstract
An evaluation circuit, sensitive of the frequency of an applied signal, is connected to the motor to sense the a-c component of the pulsating current flow through the motor, the evaluation circuit preferably including a filter matched to the frequency of the a-c component at operating speed to enhance the a-c component at operating speed or speed range with respect to other frequencies. The signal is taken across an impedance element connected in series with the motor and motor supply circuit, which may be a transformer or a low-value resistor, to provide an output voltage signal of a magnitude sufficient to unambiguously control a transistor amplifier, for example in the order of 0.1 V.