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:
Dec. 29, 1987
Filed:
May. 23, 1986
Hisashi Fujisaki, Tokyo, JP;
NEC Corporation, Tokyo, JP;
Abstract
A terminal station operating with a current supplied from a master station exchanges signals with it through cable conductors, one of the cable conductors being grounded at the master station to allow the current to return from the terminal station. A receive circuit is formed by a first differential amplifier and a first resistor network connected in a balanced relationship to input terminals of the first differential amplifier for receiving a signal from the master station in a noise-cancelling relationship with respect to the ground potential to eliminate the effect of noise generated by the passage of the current through the ground conductor. A transmit circuit includes a second differential amplifier and a second resistor network connected in a balanced relationship to input terminals of the second differential amplifier for transmitting a signal to the master station in a noise-cancelling relationship with respect to the ground potential to eliminate the effect of the noise at the output of the second differential amplifier.