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:
Oct. 10, 1989
Filed:
Nov. 12, 1987
Stanley B Wilkinson, Havertown, PA (US);
General Electric Company, Malvern, PA (US);
Abstract
A circuit for preventing the generation of an erroneous output signal from a protective relay for detecting faults in a three phase alternating current electrical power distribution system, which relay uses a full wave rectified signal as an operate quantity. The circuit includes a band pass filter having an input adapted to receive the full wave rectified signal; a center frequency which is tuned to the frequency of at least one principal harmonic component of the full wave rectified signal; a gain substantially equal to -1; and an output. A two-input summing amplifier has one input which is adapted to receive the full wave rectified signal and the other input which is connected to the output of the band pass filter. In the preferred embodiment, the circuit removes the second harmonic component of the full wave rectified signal thereby preventing the relay from generating a faulty trip signal for those faults beyond the reach of the relay which, but for the elimination of the increase in the magnitude of the DC level of the operate signal due to the contribution of the second harmonic component, would cause the relay to operate.
Data source: USPTO (United States Patent and Trademark Office) public patent records. Weekly synchronization. How IDiyas builds this profile