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:
Apr. 02, 1985
Filed:
Feb. 21, 1984
Kaichi Yamamoto, Zama, JP;
Sony Corporation, Tokyo, JP;
Abstract
A signal detecting circuit detects the presence in an input signal of a component of a predetermined frequency f.sub.p. The circuit includes a sampling arrangement for sampling the input signal at predetermined times separated by a sampling period 1/f.sub.s and providing first, second, and third signal samples. An adding circuit provides a sum signal A+C from the first and third signal samples, and a calculating circuit provides a calculated signal 2B cos .theta. from the second signal sample, where .theta. is the phase relation of the signal samples 2.pi.f.sub.s /f.sub.p. A comparator provides an output signal when the values of the sum signal A+B and the calculated signal 2B cos .theta. are substantially equal, indicating the presence of the component of interest.