Patents
Sitemap › H04 - Electric communication technique › H04M - Telephonic communication › H04M 19 - Current supply arrangements for telephone systems
Patents for H04M 19 - Current supply arrangements for telephone systems (7,475)
12/1985
12/31/1985US4562309 Telephone circuit controlled by a 2 wire - 4 wire transmission integrated circuit microprocessor with line current emergency supply
12/31/1985US4562308 Subscriber connection circuit comprising feed resistors which can be bridged in low-ohmic fashion and an indication circuit which effects different indications
12/31/1985CA1198844A1 Electronic external line repeater
12/27/1985EP0165516A2 Calling signal transmission apparatus
12/24/1985US4560843 Electronic external line repeater
12/24/1985US4560841 Telephone station which is main or remotely supplied
12/24/1985US4560835 Power supply arrangement for applying direct current to subscriber circuits
12/24/1985US4560834 Current limiter circuit for battery feed in a telephone circuit
12/18/1985EP0165087A1 Switching mode power supply
12/17/1985CA1198234A1 Method of and a circuit arrangement for determining current criteria in the lines of a telephone system
12/10/1985US4558272 Current characteristic shaper
12/10/1985US4558186 For use in a transformerless hybrid arrangement
12/10/1985US4558183 Opto-coupler interfacing circuit
12/04/1985EP0163436A2 Power supply system for CATV tap-off unit
12/04/1985EP0163308A2 Battery feed circuit for a pair of subscriber lines
12/04/1985EP0163275A2 Battery feed circuit for subscriber line
12/03/1985CA1197641A1 Telephone line interface circuit
11/1985
11/26/1985US4555595 Telephone system
11/21/1985EP0161253A1 Interface channel unit.
11/19/1985US4554412 Battery feed system for supplying power to communication circuits
11/12/1985US4552994 Apparatus for isolating the voice frequency path from the floating battery feed during signalling
11/12/1985CA1196743A1 Telephone subscriber line battery feed resistor arrangements
11/12/1985CA1196742A1 Supply for a subscriber control system
11/07/1985WO1985005003A1 Circuit for maintaining the dc voltage on an electrically isolated telecommunication line at a reference level
11/06/1985EP0160411A2 Line feed circuit for a digital signal loop
11/06/1985EP0160058A1 Electronic adapter for a telephone, enabling to provide a complementary call warning, different from a conventional ringing
11/05/1985US4551670 Circuit for maintaining the DC voltage on an electrically isolated telecommunication line at a reference level
11/05/1985CA1196433A1 Active impedance transformer assisted line feed circuit with supervision filtering
10/1985
10/22/1985US4549129 Regulator circuit
10/16/1985EP0158290A2 A wide-band high voltage amplifier for telephone exchange subscriber line interface utilizing low voltage control circuitry
10/15/1985US4547629 In a telephone circuit including a electronic memory
10/15/1985CA1195446A1 Electronic impedance-matched line repeater
10/08/1985US4546214 Line use indicator for telephone sets sharing a single line
10/08/1985CA1194967A1 Electronic subscriber junctor
10/08/1985CA1194930A1 Rectifier control system for a dc power plant system
10/01/1985CA1194627A1 Electronic circuit for detecting the lifting of a telephone handset in presence of ringing current
09/1985
09/18/1985EP0155074A2 Active impedance line feed circuit with improved ground fault protection
09/17/1985CA1193774A1 Driver circuit
09/17/1985CA1193756A1 Method of forming resistor for use in supply bridge
09/11/1985EP0154366A1 Audio transmission circuit comprising a transmit amplifier in the form of a line voltage stabiliser
09/10/1985US4540853 Apparatus for detecting a loop during ringing
09/10/1985US4540852 Electronic subscriber junctor
09/03/1985US4539438 Active impedance transformer assisted line feed circuit with supervision filtering
09/03/1985US4539437 Stored program power control system for improving energy efficiency for telephone sets connected into a local telephone communications system
08/1985
08/27/1985US4538032 Interface circuit with impedance adaptation means
08/21/1985EP0152178A2 Active impedance line feed circuit
08/20/1985US4536619 Ringing signal detection circuit
08/20/1985US4536614 Supervision and dial pulse detection circuit for a telephone subscriber line
08/15/1985WO1985003614A1 Circuit arrangement for the electric supply of devices in a telephone set
08/13/1985US4535303 Driver circuit
08/07/1985EP0150853A2 Electric power supply device
08/06/1985US4533792 Circuit for switching between ring signal and message waiting signal without bell tap
08/06/1985CA1191645A1 Method of and a circuit for energizing a subscriber's circuit in a telephone system
07/1985
07/30/1985US4532384 For terminating a two wire communication line
07/30/1985US4532382 Power supply for telephone equipment memory devices
07/30/1985US4532381 Active impedance line feed circuit
07/30/1985CA1191212A1 Universal telephone ringing generator
07/16/1985CA1190682A1 Line feed circuit including negative impedance circuit
07/16/1985CA1190678A1 Digital supervisory circuit for a telephone system
07/09/1985US4528425 Method of and circuitry for detecting, at a telephone exchange, the lifting of a subscriber's handset in response to ringing current emitted by the exchange
07/03/1985EP0147230A2 Subscriber line interface circuit having an impedance synthesizer
07/02/1985US4527157 Single fault tolerant CCIS data link arrangement
06/1985
06/26/1985EP0146183A1 Interface arrangement for a subscriber set
06/25/1985US4525602 Method of and a circuit for energizing a subscriber's circuit in a telephone system
06/19/1985EP0145047A2 Telecommunication line circuit and associated polarity reversal circuit
06/18/1985US4524246 SLIC II--common-mode current rejection
06/18/1985US4524245 Ring trip detection system
06/18/1985CA1189209A1 Detector circuit for communication lines
06/11/1985US4523058 In a telephone handset
06/06/1985EP0089350A4 Electronic terminator circuit.
06/05/1985EP0143481A1 DTMF-telephone set with multiple use of the logic of the digital tone generator
06/05/1985EP0143473A1 Electronic contacts and associated devices
06/05/1985EP0143435A2 Improvements in or relating to telephone circuits, monolithically integrated, for ring trip detection
05/1985
05/22/1985EP0142137A2 High impedance power supply for an electronic circuit powered by a telephone line
05/22/1985EP0141971A2 Circuit arrangement for supplying power either by the mains or remotely to a subscriber set
05/22/1985EP0141934A1 Circuitry for providing and connecting the ringing voltage for subscriber stations in a time division multiplex exchange
05/21/1985US4518828 Transmission circuit for an electronic telephone set
05/09/1985WO1985002083A1 Interface channel unit
05/07/1985CA1186825A1 Transistor bridge rectifier circuit for telephone purposes
05/02/1985EP0139594A1 Method and apparatus for the detection of a transition of the direct current component of a periodic signal, in particular for subscriber loop interface circuits
05/02/1985EP0139103A2 Overvoltage protection circuit for slic
04/1985
04/30/1985US4514596 Telephone handsets
04/30/1985US4514595 For supplying energized direct current to leads in a communication line
04/25/1985WO1985001853A1 Electronic adapter for a telephone, enabling to provide a complementary call warning, different from a conventional ringing
04/24/1985EP0137901A2 Arrangement for a telephone apparatus
04/23/1985CA1186083A1 Subscriber line circuit comprising a controllable dc/dc converter as a battery feed circuit
04/17/1985EP0137012A1 Method and circuitry for encoding telephone ringing signals
04/16/1985US4512015 Digital time-division switch
04/16/1985US4511763 Preparing antibodies and/or cloning antibody producing cells
04/03/1985EP0136077A2 Telephone line interface circuit
04/03/1985EP0135538A1 Electronic tone ringer
04/02/1985US4508937 Method and circuitry for encoding telephone ringing signals
04/02/1985CA1185023A1 Tone source for telephone systems
03/1985
03/28/1985WO1985001404A1 Electronic contacts and associated devices
03/27/1985EP0135412A1 Regulated powering circuit for a telephone set
03/27/1985EP0134886A2 Circuit arrangement for the transmission of signalling information from a public exchange to subscribers of a telephone exchange, especially a private telephone exchange
03/27/1985EP0134867A1 Telephone ringing circuit realisable as an integrated circuit
03/26/1985US4507525 Transistorized bridge rectifier circuit with overcurrent protection for use in telephones
03/20/1985EP0134229A1 Borsht/slic auto balancing technique.
03/19/1985US4506114 Telephone circuit
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