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:
Feb. 26, 1991
Filed:
Mar. 01, 1989
David J McCabe, Winchester, GB;
Shaye Communications Limited, Winchester, GB;
Abstract
A waveform encoder/decoder includes an encoder having an input for an audio signal to be encoded, and an output whereby the digitally encoded signal is passed to a transmission link and then to a corresponding decoder. The encoder includes detectors for monitoring the digital output signal for slope overload and idle pattern respectively and setting a corresponding value in a state machine. The value stored in the state machine is used to control a pulse width generator which in turn controls the enable time of a tri-state gate connected in the feedback path from the output back to the input. An R.C. filter is used to reconstruct the digital output from the gate to form an estimate of the audio input signal, and this estimated signal is compared with the actual input signal in a comparator. A D-type flip-flop is used to digitize the output from comparator to generate the signal to be output to the transmission link. The circuit, being fully digital, ensures improved repeatability and is particularly convenient and low in cost.