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:
Mar. 05, 1985
Filed:
Jun. 17, 1982
Frederick K Schultz, Bringhurst, IN (US);
General Motors Corporation, Detroit, MI (US);
Abstract
A stereo pilot signal detector for an AM stereo receiver connects an input signal to a train of pulses corresponding to zero crossings of the input signal. These pulse lock a shift register having a data input connected with a timer which is reset from the pulses after the shift register is clocked. The timer produces a logic '1' input to the register during a time interval extending on either side of the zero crossings of the stereo pilot signal. If four consecutive zero crossings occur within the window, the stereo decoder and an indicator are enabled. Thereafter, if three out of four zero crossings occur outside said interval, the stereo decoder and indicator are disabled.