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)
06/1983
06/28/1983CA1149090A1 Electronic tone ringer
06/22/1983EP0081864A1 Polarity guard circuit
06/14/1983US4388500 Electronic hybrid
06/14/1983US4388498 Voltage stabilizer suitable for use in a telephone set
06/14/1983US4388497 Telephone power supply arrangement
06/14/1983CA1148286A1 Calling device for subscriber automatic telephone installation with extension stations
06/07/1983US4387273 Subscriber line interface circuit with impedance synthesizer
06/01/1983EP0080396A1 Integrated circuit microprocessor-controlled telephone two wire/four wire transmission circuit, and line current safeguard powering
05/1983
05/25/1983EP0079463A1 Method and circuit for registering the loop current criteria in a telecommunication exchange
05/24/1983US4385385 Circuit for monitoring a digital signal generator
05/24/1983US4385336 Current supplying circuit with shorted-to-ground fault detecting function
05/17/1983US4384171 Automatic telephone silencer
05/11/1983EP0078355A1 Line circuit containing impedance adaptation means
05/11/1983EP0078347A1 Telecommunication line high-efficiency operational amplifier
05/10/1983CA1146288A1 Ringing control device
05/04/1983EP0078089A1 Method of making a power supply suljected to large overload and power supply made by this method
04/1983
04/26/1983CA1145497A1 Interface system isolating a subscriber subset from a telephone switching system
04/26/1983CA1145494A1 Ringing signal generator
04/26/1983CA1145493A1 Digitally activated ringing circuit for generation of ac voltages
04/19/1983US4380688 Telephone ringing range extender
04/19/1983US4380687 Power supply control circuit for subscriber carrier telephone system
04/14/1983WO1983001355A1 Detector circuit for communication lines
04/13/1983EP0076402A1 Regulation device for controlling symmetrically arranged, independent constant current sources
04/12/1983US4380064 Digital audio signal control system for a timedivision switching system
04/06/1983EP0075914A1 Subscriber line circuit comprising a controllable DC/DC converter as a battery feed circuit
04/05/1983US4379210 Ringing detector for use by the deaf
03/1983
03/31/1983WO1983001163A1 Balanced current multiplier circuit for a subscriber loop interface circuit
03/31/1983WO1983001162A1 Electronic terminator circuit
03/29/1983CA1143877A1 Signalling and channel loop test circuits for station carrier telephone system
03/22/1983CA1143494A1 Arrangement for applying signals to a telephone line
03/22/1983CA1143493A1 Connecting circuit for a telephone line
03/22/1983CA1143492A1 Interface circuits
03/17/1983WO1983000959A1 Telephone line circuit
03/15/1983US4376876 DC Supply for an electronic signalling device
03/09/1983EP0073462A2 Subscriber line circuit
03/08/1983CA1142662A1 Electronic tone ringer
03/08/1983CA1142609A1 Relaxation oscillator with plural constant current sources
02/1983
02/23/1983EP0072705A2 Amplifiers
02/22/1983US4375015 Improved electronic hybrid circuit
02/15/1983US4374307 Ringer system for a telephone
02/15/1983US4374306 Zero-loss automatic polarization protection device
02/15/1983US4374303 Power supply control circuit for subscriber carrier telephone system
02/15/1983CA1141454A1 Device for increasing the parallel inductance of a transformer
02/09/1983EP0071301A1 Driver circuit
02/08/1983US4373118 Battery feed circuit
02/08/1983US4373117 DC to DC converter for line powered modem
02/01/1983US4371789 Power control arrangement
01/1983
01/25/1983US4370527 Arrangement for feeding a subscriber device
01/25/1983US4370526 Arrangement for applying a ringing voltage to a subscriber's line
01/19/1983EP0069964A1 Device for power distribution
01/11/1983CA1139470A1 Transformerless line interface circuit
01/04/1983US4367376 Electronic telephone ringer including anti-bell tap provisions
12/1982
12/28/1982CA1138581A1 Loop, dial pulse and ring trip detection circuit with capacitive shunt network
12/21/1982US4365116 Digital ringing-signal generator
12/21/1982CA1138140A1 Transmission bridge for a telephone subscriber's line circuit
12/21/1982CA1138139A1 Transmission bridge for a subscriber's circuit
12/21/1982CA1138138A1 Line circuit
12/21/1982CA1138137A1 Electronic audio signalling device for telephones
12/15/1982EP0066577A1 Pulse with modulated voltage converter for generating a preferably sinusoidal alternating voltage.
12/14/1982CA1137667A1 Arrangement for applying a signal to a transmission line
12/14/1982CA1137666A1 Connecting circuit for a telephone line
12/08/1982EP0066011A1 Telecommunication system
12/07/1982US4362908 Circuit arrangement for emitting ringing signals in a telephone system
11/1982
11/30/1982US4361732 Trunk interface circuit with current compensation
11/24/1982EP0065097A1 Electronic message generator connected to a telephone line
11/16/1982US4359680 Reference voltage circuit
11/16/1982US4359610 Telephone ringing circuit
11/16/1982US4359609 Circuit with feedback for controlling the impedance thereof
11/16/1982CA1135885A1 Ringing signal generator
11/09/1982US4358645 Loop sensing circuit for use with a subscriber loop interface circuit
11/02/1982US4357495 Telephone line feed
11/02/1982US4357494 Impedance canceller circuit
10/1982
10/26/1982US4356355 Apparatus for detecting the closure of a subscriber's line during ringing
10/26/1982US4356354 Electronic subscriber junctor
10/19/1982US4355209 Programmable line circuit
10/19/1982US4355206 Ringing control device
10/12/1982US4354062 Communication system signaling circuit
09/1982
09/28/1982CA1132735A1 Three-terminal power supply circuit for telephone set
09/21/1982US4350964 Impedance generator circuit
09/21/1982CA1132275A1 Subscriber's connecting network comprising a symmetrical power amplifier for feeding a subscriber's line
09/14/1982US4349703 Programmable ring signal generator
09/14/1982CA1131821A1 Longitudinal balance arrangement for two-to-four telecommunication line circuits
09/14/1982CA1131818A1 Current limited subscriber line feed circuit
09/14/1982CA1131700A1 Power supply providing constant power output
08/1982
08/31/1982CA1130940A1 Current supply circuit for telephone exchange
08/25/1982EP0058470A1 Trunk interface circuit with current compensation
08/24/1982US4346422 Power-distribution network for telecommunication system
08/24/1982US4346265 Annunciator
08/18/1982EP0057840A1 Subscriber circuit
08/17/1982US4345169 Zero crossing detector
08/17/1982US4345117 Telephone line feed circuit
08/10/1982US4343971 Subscriber drop circuit for controlling drop current with load and maximizing power usage
08/04/1982EP0057009A1 Current supply circuit
07/1982
07/27/1982US4341991 Voltage stabilizer suitable for a telephone set
07/27/1982US4341928 Ringing signal supply
07/20/1982US4340869 Amplifier for use in a line circuit
07/20/1982US4340785 Ringing signal supply
07/06/1982CA1127335A1 Programmable ringing generator
06/1982
06/24/1982WO1982002134A1 Pulse width modulated voltage converter for generating a preferably sinusoidal alternating voltage
06/22/1982US4336424 Circuit arrangement for monitoring operating conditions of direct current devices
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