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:
Jul. 19, 1977
Filed:
Feb. 17, 1976
Applicant:
Inventor:
Robert Roger Cordell, Tinton Falls, NJ (US);
Assignee:
Bell Telephone Laboratories, Incorporated, Murray Hill, NJ (US);
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
H03B / ;
U.S. Cl.
CPC ...
331 14 ; 324 / ; 331 12 ; 331 64 ;
Abstract
A narrow-band tone decoder has a controllable oscillator, connected in a fast-capture phase-locked loop, for generating a signal having a frequency determined by a control signal produced within the loop. A synchronous detector, which responds to an input signal of the tone decoder and to a signal from the controllable oscillator, produces a signal having a magnitude dependent upon the magnitudes of the input signal and of the signal from the controllable oscillator. A window comparator monitors the control signal within the loop for deciding when the generated signal is within a predetermined frequency range.