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. 29, 1979
Filed:
Feb. 09, 1978
Robert S Peterson, Williamsville, NY (US);
Westinghouse Electric Corp., Pittsburgh, PA (US);
Abstract
An active filter is disclosed for providing improved notch and band pass filters. The output to input frequency response of an active filter is mathematically expressed as a ratio of two polynominals in the Laplace operator S. In any notch filter, the coefficient of the S term in the numerator must be reduced to zero, while in any band pass arrangement the coefficient of the S term in the denominator is reduced to zero. The improved notch filter provides an input circuit for the operational amplifier portion of the filter which eliminates the S term in the numerator so that adjustments to reduce this term are unnecessary. Similarly, in the improved band pass filter, the S term in the denominator is eliminated in the feedback circuit provided for the operational amplifier, so that adjustment is unnecessary to eliminate the coefficient of S.