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:
Aug. 11, 1987
Filed:
Dec. 02, 1985
Applicant:
Inventor:
Daniel Lynch, Jackson, NJ (US);
Assignee:
Keptel, Inc., Tinton Falls, NJ (US);
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
H04M / ; H04B / ;
U.S. Cl.
CPC ...
379 22 ; 379399 ; 379 29 ;
Abstract
An apparatus and method for sensing a predetermined tone signal transmitted on a transmission line, such as a telephone transmission line, and for generating a signal indicating the presence of the tone signal. The apparatus comprises a tone detector circuit including an amplifier, bandpass filter and comparator, a power supply for generating power for the detector circuit from a voltage present on the transmission line and logic circuitry for gating pulses of power from the power supply to the detector circuit on a periodic basis thereby to enable the detector circuit to check for the presence of the tone signal during the durations of the power pulses.