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Class Information
Number: 379/378
Name: Telephonic communications > Supervisory or control line signaling > Using line or loop condition detection (e.g., line circuit) > With current controlling electromagnetic core device (e.g., hall-effect device)
Description: Subject matter having a magnetizable element within a coiled conductor for current control.

Patents under this class:
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Patent Number Title Of Patent Date Issued
8447029 Communication apparatus and control method therefor May. 21, 2013
RE43706 Fallback function telecommunications device Oct. 2, 2012
7907720 Test method for line equipment including a hybrid circuit and line equipment for its implementation Mar. 15, 2011
7548616 Termination device for a telephone line Jun. 16, 2009
7447305 Method and arrangement for filtering of signals Nov. 4, 2008
7346149 Method and apparatus for reversibly correcting nonlinear impairments in a communications channel Mar. 18, 2008
7181005 Telephone interface circuit Feb. 20, 2007
7043012 Method and apparatus for ring again feature for a telephone system May. 9, 2006
7027590 Dynamic allocation of overhead voltage to support simultaneous transmission of signals on a telecommunication line Apr. 11, 2006
6980643 Fallback function telecommunications device Dec. 27, 2005
6393123 Method and modem circuit for determining connection status of a phone line May. 21, 2002
6233462 Portable terminal device for automatically controlling transmitting voice level and calling sound level May. 15, 2001
6020732 Flux cancelling transformer line circuit Feb. 1, 2000
5991386 Method and arrangement for the connection of multiple terminals to one subscriber line of the telephone network, and a terminal Nov. 23, 1999
5970139 T1 channel bank control process and apparatus Oct. 19, 1999
5912513 Method and apparatus for reducing power dissipation in DC termination circuit Jun. 15, 1999
5859906 Telephone switch hook interface circuit Jan. 12, 1999
5729589 Apparatus and method for incoming call detection and alarm circuitry for cellular telephones Mar. 17, 1998
5651052 Apparatus and method for incoming call detection and alarm circuitry for cellular telephones Jul. 22, 1997
5539820 Protection of active telephone line interface circuits Jul. 23, 1996
5535272 Sensor circuit for a telephone line Jul. 9, 1996
5526420 Communication apparatus Jun. 11, 1996
5515433 Resistance forward telephone line feed circuit May. 7, 1996
5479499 Sensor circuit for voice/fax switch with cascaded amplifier circuit Dec. 26, 1995
5311587 Sensor circuit for telephone line May. 10, 1994
5289537 On-hook transmission circuit in cable line Feb. 22, 1994
5138658 Subscriber line interface circuit providing regulated current Aug. 11, 1992
5065088 Current sensor circuit Nov. 12, 1991
4896093 Electronic inductor Jan. 23, 1990
4893331 System allowing selective connection of various types of external apparatuses to telephone set Jan. 9, 1990
4878244 Electronic hybrid circuit Oct. 31, 1989
4760379 Fail-safe high temperature alarm Jul. 26, 1988
4707673 Directional coupling transformer for bi-directional full duplex data bus Nov. 17, 1987
4540853 Apparatus for detecting a loop during ringing Sep. 10, 1985
4516070 Magnetic current sensor with offset and load correction May. 7, 1985
4480152 Methods and apparatus for protecting line relay contacts in a telephone switching system Oct. 30, 1984
4431869 Telephone line feed Feb. 14, 1984
4389543 Telephone-activated audio control circuit Jun. 21, 1983
4355206 Ringing control device Oct. 19, 1982
4355209 Programmable line circuit Oct. 19, 1982
4310724 Current detector circuit Jan. 12, 1982
4300021 Line circuit controlled by a hall effect device Nov. 10, 1981
4278938 Electromagnetic arrangement for measuring electrical current Jul. 14, 1981
4278939 Electromagnetic arrangement for measuring electrical current Jul. 14, 1981
4274051 Electromagnetic arrangement for measuring electrical current Jun. 16, 1981
4237345 Transformer with integral reed contact Dec. 2, 1980
4191859 Loop, dial pulse and ring trip detection circuit with capacitive shunt network Mar. 4, 1980
4166928 Loop, dial pulse and ring trip detection circuit Sep. 4, 1979
4119806 Subscriber's line equipment for a telephone exchange Oct. 10, 1978
4118597 Method and apparatus for detecting direct currents in a transmission line Oct. 3, 1978

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