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:
Sep. 13, 1994
Filed:
May. 03, 1993
Frank X Garcia, Aurora, IL (US);
Bruce R Miller, Aurora, IL (US);
Teltrend Inc., St. Charles, IL (US);
Abstract
A compensation circuit for adjusting the gain or loss of a four to two wire hybrid circuit in a telephone system automatically, regardless of the length of the telephone line interconnected to the hybrid circuit. The compensation circuit includes a converter, interface, gate array, and controller. The converter, which includes an amplifier with a variable gain, is connected to a digital carrier transmission line. The converter accepts a digital data signal and converts it to an analog intermediate signal. The interface receives the analog intermediate signal and transmits an analog telephone signal, along a customer loop telephone line, to a telephone. The interface also includes a pulse width modulated power converter for which the pulse width varies according to the length of the telephone line between the compensation circuit and the telephone. The gate array senses the pulse width and responsively provides a measured signal to the controller. The controller receives the measured signal, representing the pulse width, as well as a voltage signal, representing the voltage powering the interface, and responsively adjusts the gain or loss of the gain of the variable amplifier.