Patents
Sitemap › H04 - Electric communication technique › H04M - Telephonic communication › H04M 3 - Automatic or semi-automatic exchanges
Patents for H04M 3 - Automatic or semi-automatic exchanges (99,881)
05/1983
05/17/1983CA1146631A1 Signal distributor test arrangement
05/10/1983US4383137 Key telephone system with multiple processor control
05/10/1983CA1146288A1 Ringing control device
05/10/1983CA1146248A1 Multiport conference circuit with multi-frame summing
05/10/1983CA1146247A1 Multiport conference circuit with voice level coding
05/10/1983CA1146246A1 Multiport conference circuit with multi-frame summing and voice level coding
05/03/1983US4382295 Digital conference time slot interchanger
05/03/1983US4382294 Telephone switching control arrangement
04/1983
04/28/1983WO1983001549A1 Telephone switching control arrangement
04/19/1983CA1145017A1 Method of determining existing service capabilities of telephone exchange equipment
04/12/1983US4379993 Pulse failure monitor circuit employing selectable frequency reference clock and counter pair to vary time period of pulse failure indication
04/06/1983EP0075998A1 Digital telephone exchange comprising means for processing packet-switched data
04/06/1983EP0075652A1 Information display circuitry for a telephone set, an operator's desk or an operator's apparatus
03/1983
03/30/1983EP0075503A1 Desk for an automatic telephone switching system
03/30/1983EP0075310A1 Circuit arrangement for telecommunication exchanges, especially telephone exchanges, with devices for securing the transmission of coded signals
03/23/1983EP0074663A2 Aid for a receptionist
03/22/1983CA1143493A1 Connecting circuit for a telephone line
03/22/1983CA1143491A1 Current detection circuit arrangement for an automatic telephone exchange
03/16/1983EP0074319A2 Telephone set
03/09/1983EP0073462A2 Subscriber line circuit
03/07/1983EP0042861A4 Automated conversation system.
03/03/1983WO1983000790A1 Wideband switching architecture
03/01/1983US4375582 Telephone answering system and method
02/1983
02/23/1983EP0072721A1 System for the localization of loops and interruptions in a two-wire line
02/17/1983WO1983000592A1 Semiconductor crosspoint linearizing arrangement
02/15/1983US4374361 Clock failure monitor circuit employing counter pair to indicate clock failure within two pulses
02/15/1983CA1141453A1 Shared maintenance terminal system
02/08/1983US4373121 Maintenance termination device
02/08/1983US4373120 Line test termination device
02/01/1983US4371758 Defective short holding-time trunk identifying method
02/01/1983US4371752 Electronic audio communication system
02/01/1983CA1140688A1 Telephone summing circuit
01/1983
01/25/1983US4370526 Arrangement for applying a ringing voltage to a subscriber's line
01/25/1983CA1140283A1 Test set
01/18/1983US4369341 Customer line test termination device
01/18/1983US4369339 Method for completing the connection between a telephone exchange and the phone subscriber's line in response to the reception, at the exchange, of a pre-established code
01/11/1983US4368363 Audible line test termination device
01/04/1983CA1138967A1 Integrated automatic call distribution facility and pbx system
01/04/1983CA1138966A1 Method and means for digital conferencing
12/1982
12/29/1982EP0067839A1 Voltage controlled transient protection unit.
12/28/1982US4366350 Control system for telephone switching system
12/28/1982US4365863 Optical switch for a very large number of channels
12/28/1982CA1138581A1 Loop, dial pulse and ring trip detection circuit with capacitive shunt network
12/28/1982CA1138580A1 Digital intercept recorder/announcer system
12/23/1982WO1982004516A1 Hook flash signal actuated telephone control device
12/23/1982WO1982004491A1 A method for implementing a calling process bound to a person
12/22/1982EP0067268A2 Hook flash actuated telephone control device
12/22/1982EP0067154A1 On-hook/off-hook detector circuit
12/21/1982US4365117 Telephone hold circuit
12/21/1982CA1138140A1 Transmission bridge for a telephone subscriber's line circuit
12/21/1982CA1138139A1 Transmission bridge for a subscriber's circuit
12/21/1982CA1138079A1 Device for switching signals by optical means and switching units incorporating this device
12/21/1982CA1138078A1 Printer control system
12/15/1982EP0067006A1 Digital conference circuit and method
12/15/1982EP0066947A1 Successive frame digital multiplexer with increased channel capacity
12/15/1982EP0066597A1 Telephone exchange.
12/15/1982EP0066576A1 A method and apparatus for transferring the same information to a plurality of subscribers.
12/14/1982CA1137665A1 Self-adjusting hybrid network
12/07/1982US4362908 Circuit arrangement for emitting ringing signals in a telephone system
12/01/1982EP0065598A1 Improvements in telecommunication receivers
11/1982
11/30/1982CA1136741A1 Expandable link telephone intercom system
11/23/1982US4360910 Digital voice conferencing apparatus in time division multiplex systems
11/23/1982US4360827 Method and means for interactive audio and video conferencing
11/23/1982US4360709 Loop detecting circuit
11/16/1982US4359631 Self-service terminal
11/16/1982US4359606 Voice switching control system
11/16/1982US4359603 CVSD Multiple conference system
11/09/1982US4358639 Permanent signal holding module
11/09/1982CA1135431A1 Device control system
11/03/1982EP0063672A1 Telephone music device
11/02/1982US4357674 PCM Signal calculator
11/02/1982US4357493 Method and apparatus for storing announcements in a communications system
11/02/1982CA1134970A1 Ring trip apparatus for a line circuit connected to dco switch
10/1982
10/27/1982EP0063502A1 Arrangement for locating faults in a two-wire line
10/26/1982US4356356 Headset/groundcord tester apparatus
10/26/1982US4356355 Apparatus for detecting the closure of a subscriber's line during ringing
10/26/1982US4356352 Circuit arrangement for telephone exchange systems having time staggered charge metering pulse frequencies
10/26/1982US4356348 Techniques for detecting a condition of response on a telephone line
10/20/1982EP0062976A1 Switchboard control system
10/19/1982US4355329 Remote station
10/19/1982US4355308 Circuit arrangement for operating opto-electronic display elements assigned to terminal devices, in particular in telephone system
10/19/1982US4355209 Programmable line circuit
10/19/1982US4355208 Telephone call denial system
10/19/1982US4355207 Telephone answering system
10/19/1982US4355206 Ringing control device
10/13/1982EP0062295A1 Digital connection network
10/13/1982EP0062294A1 Line group terminal spare device
10/13/1982EP0009488B1 Arrangement for measuring the ratio between a number of events occurring after each other in a first and second series of events
10/12/1982US4354062 Communication system signaling circuit
10/12/1982CA1133620A1 Pbx field display
10/05/1982US4352959 Device for visual display of telephone operation symbols
10/05/1982US4352956 Multi-responder telephone intercept apparatus
09/1982
09/29/1982EP0061189A1 Subscriber line testing system
09/28/1982US4352182 Method of and device for testing the quality of digital speech-transmission equipment
09/28/1982US4351987 Telephone line circuit hold arrangement
09/28/1982US4351986 Electronic telephones with cooperative interaction between a master set and members' sets in a group
09/22/1982EP0060598A1 Subscriber line circuit test system
09/22/1982EP0060318A1 Broadband switching system
09/21/1982US4350849 Varying impedance line test termination device
09/21/1982CA1132275A1 Subscriber's connecting network comprising a symmetrical power amplifier for feeding a subscriber's line
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