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)
06/1982
06/22/1982US4336423 Device for increasing the parallel inductance of a transformer
06/22/1982CA1126425A1 Programmable power supply system
06/02/1982EP0052835A1 Circuit for deriving a control signal to permit or to block the emission of tones by a tone cell circuit for telecommunication systems
06/01/1982CA1124898A1 Pcm tone signal generator
05/1982
05/25/1982US4331913 Precision negative impedance circuit with calibration
05/25/1982US4331838 Telephone ringer isolator circuit arrangement
05/13/1982WO1982001635A1 Improvements in or relating to line interface circuits
05/12/1982EP0051495A1 Ring scheduling apparatus for a digital multiplexed telecommunication system
05/12/1982EP0051446A1 Improvements in or relating to line interface circuits
05/04/1982CA1123131A1 Transformerless trunk circuit
05/04/1982CA1123130A1 Variable loop length compensated optocoupled circuit
04/1982
04/27/1982US4327254 Ringer circuit for telephone
04/27/1982US4327253 Circuit arrangement for consecutively monitoring operating conditions of direct current devices
04/13/1982US4325137 Power supply system to terminal equipment through an optical fiber cable
04/13/1982CA1121926A2 Pulse width modulating signal generator and method
04/07/1982EP0048940A1 Subscriber connecting circuit
03/1982
03/31/1982EP0048477A1 Subscriber line interface circuit utilizing impedance synthesizer and shared voltage source for loop current regulation control
03/30/1982US4322586 Transformerless line interface circuit
03/23/1982US4321431 Trunk circuit with single coupling transformer
03/23/1982US4321430 Subscriber's connecting network comprising a symmetrical power amplifier for feeding a subscriber's line
03/16/1982US4320260 Circuit arrangement for determining the connection condition of a subscriber line in a telecommunications network
03/16/1982US4320258 Arrangement for requesting service for called telephone subscribers
03/10/1982EP0047046A1 Arrangement for exchanging signals between separated circuit arrangements
03/09/1982US4319094 Three-terminal power supply circuit for telephone set
03/09/1982US4319093 Transmission bridge for a subscriber set
03/03/1982EP0046588A1 Method of and circuit arrangement for supplying current to a two-wire telecommunications line
03/02/1982US4317963 Subscriber line interface circuit utilizing impedance synthesizer and shared voltage source for loop current regulation control
03/02/1982CA1119330A1 Subscriber's circuit
03/02/1982CA1119081A1 Determination of glycosylated hemoglobin in blood
02/1982
02/23/1982CA1118922A1 Universal signal generator for generating telephone system high level signals
02/18/1982WO1982000554A1 Loop sensing circuit for use with a subscriber loop interface circuit
02/16/1982US4316135 Circuit arrangement for feeding modules in user stations
02/09/1982US4315207 Current controlled battery feed circuit
02/09/1982US4315206 Current supply circuit for telephone exchange
02/09/1982US4315109 Electronic ring sounder for a speaker telephone
02/09/1982US4315106 Apparatus for regulating current supplied to a telephone line signal of the type employed in digital telephone systems
02/04/1982WO1982000372A1 Current limiting circuit
02/02/1982US4314196 Current limiting circuit
02/02/1982US4314106 Line circuit
02/02/1982CA1117636A1 Telephone exchange
01/1982
01/27/1982EP0044356A1 Circuit for the connection of a subscriber apparatus to a subscriber connection line
01/26/1982US4313034 Connecting circuit for a telephone line
01/26/1982CA1117231A1 Signal processing apparatus for subscriber circuits
01/19/1982CA1116767A1 Electronic bridge circuit for supplying dc power and tone signals to subscriber line
01/12/1982US4310733 Arrangement for applying signals to a telephone line
01/12/1982US4310728 Ringing device for a private automatic branch exchange
01/12/1982CA1116330A1 Telephone subscriber's loop power control circuit
01/12/1982CA1116329A1 Loop, dial pulse and ring trip detection circuit
01/05/1982US4309748 DC/DC Stabilized voltage converter unit
01/05/1982US4309664 Digital energy line sensor
01/05/1982US4309578 Telephone ringer load simulator
01/05/1982US4309574 Electronic tone ringer
01/05/1982CA1115869A1 Subscriber electronic equipment with two wire - four wire conversion circuit for telephone exchange
12/1981
12/22/1981CA1114972A1 Telephone line circuit
12/15/1981US4306122 Telephone line circuit
12/15/1981US4306119 Telephone outpulsing circuit
12/15/1981US4306118 Telephone set ringing current injection device
12/15/1981CA1114536A1 Ringing generator
12/08/1981US4304969 Power circuit for loudspeaker telephone
12/08/1981CA1114084A1 Electronic telephone circuit for subscriber-line
11/1981
11/24/1981US4302636 Subscriber's electronic line equipment comprising a two-wire-four-wire conversion circuit for a telephone exchange
11/17/1981US4301335 Visual telephone or other annuciator ringing indicator
11/17/1981US4301334 Telecommunication subscriber line access circuit with ground key and insulation fault indication
11/17/1981CA1112776A1 Electronic tone ringer
11/10/1981US4300023 Hybrid circuit
10/1981
10/28/1981EP0038594A1 Electronic line junctors
10/27/1981US4297531 Circuit for suppressing noise influences in the evaluation of signal states on transmission lines
10/27/1981CA1111589A1 Direct coupled transformerless hybrid
10/27/1981CA1111587A1 Circuit for supplying direct current to telephone station sets
10/27/1981CA1111586A1 Circuit for electronic subscriber feed
10/21/1981EP0037940A1 Circuit for a two-wire coupling of a telephone subscriber with a line for outgoing and a line for incoming signals
10/20/1981US4296337 Resistance detector with delayed hysteresis
10/14/1981EP0037540A2 Method and circuit for feeding call signals to telecommunication lines, especially in telephone exchanges
10/13/1981CA1110788A1 Telephone set with loop current interruption timing control
10/07/1981EP0037111A1 Circuit for generating ringing signals for telecommunication lines
10/07/1981EP0036979A1 Signalling process for telecommunication exchanges, especially telephone exchanges
09/1981
09/29/1981US4292604 Relaxation oscillator with plural constant current sources
09/29/1981US4292479 Separation and balance device for telephone exchanges
09/29/1981US4292478 Interface circuits
09/29/1981US4292473 Loop supervision circuit
09/16/1981EP0035727A1 Power supply system for electronic assemblies
09/15/1981US4289939 Longitudinal balance arrangements for two-to-four wire telecommunication line circuits
09/15/1981US4289933 Dial pulse detection
09/15/1981CA1109173A1 Singing preventive system
09/15/1981CA1109172A1 Supply circuit for a subscriber's line circuit
09/15/1981CA1109171A1 Supply arrangement for a line circuit
09/15/1981CA1109170A1 Arrangement for measuring the line condition of a subscriber's line circuit by means of a measuring resistor
09/09/1981EP0035180A2 Circuit arrangement for increasing the inductance of a transformer
09/09/1981EP0035067A1 Arrangement for powering a subscriber unit
09/01/1981US4287393 Transmission bridge for a subscriber's circuit
09/01/1981US4287392 Integrated circuitry for exchanging signals between telephone station and central office
08/1981
08/26/1981EP0034384A1 Arrangement for applying a ringing voltage to a subscriber's line
08/26/1981EP0034339A1 Telephone circuit for off-hook detection during ringing
08/19/1981EP0033933A2 Process for feeding audible tones into conference communications
08/18/1981US4285057 Sampling gate for TDM telecommunication system
08/18/1981US4284854 Universal signal generator for generating telephone system high level signals
08/18/1981US4284853 Telecommunication subscriber line access circuit with ground key indication and a device for call signal generation
08/11/1981US4283604 Current source circuits with common mode noise rejection
08/05/1981EP0033162A2 Digital tone ringer
08/04/1981US4282410 Ringing signal generator
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