Signalling by currents in one or other or both line wires or additional wires

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H04Q5/04

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Parent Industries

HELECTRICITY H04Electric communication H04QSELECTING H04Q5/00Selecting arrangements wherein two or more subscriber stations are connected by the same line to the exchange

Current Industry

H04Q5/04Signalling by currents in one or other or both line wires or additional wires

Industries

Patents Grantslast 30 patents

Information Patent Grant
Programmable selective ringing circuit and method for party telepho...
- Patent number 4,761,810
- Issue date Aug 2, 1988
- Keptel, Inc.
- Steven B. Perry
- H04 - ELECTRIC COMMUNICATION TECHNIQUE
Information Patent Grant
Communication circuit with combined power feed and data transmissio...
- Patent number 4,173,714
- Issue date Nov 6, 1979
- TIE/Communications, Inc.
- Alan Bloch
- H04 - ELECTRIC COMMUNICATION TECHNIQUE