Patents
Sitemap › H04 - Electric communication technique › H04M - Telephonic communication › H04M 11 - Telephonic communication systems specially adapted for combination with other electrical systems
Patents for H04M 11 - Telephonic communication systems specially adapted for combination with other electrical systems (53,055)
02/1979
02/20/1979CA1049169A1 Telephone troubleshooting circuit for electric motor drives
02/20/1979CA1048938A2 Control current generator for central dictation system
02/06/1979CA1047941A2 Control signal decoder particularly for a central dictation system
02/06/1979CA1047940A1 Central dictation system
01/1979
01/30/1979US4137429 Digital dialers for use in the security field
01/30/1979CA1047658A1 Method for detecting the presence of speech band activity in a telephone connection and a circuit for carrying out such method
01/24/1979EP0000459A1 Arrangement for the remote display of progressive information
01/23/1979US4136261 Automatic answering device in facsimile
01/16/1979USRE29884 Key telephone system for subscribers
01/16/1979CA1046420A1 Central dictation system
12/1978
12/19/1978US4130738 Bidirectional data transfer and storage system
12/19/1978US4130732 Remote alarm reset apparatus
12/19/1978CA1044605A1 Power line communication system having a protective terminating impedance arrangement
12/12/1978CA1044388A1 Intercom call signaling mechanism
11/1978
11/21/1978US4126762 Method and system for accumulating data over nondedicated telephone lines
11/07/1978US4124895 Acoustic measuring system
11/07/1978US4124773 Audio storage and distribution system
10/1978
10/24/1978US4122307 Telephone voice frequency response system for message recording
10/24/1978US4122305 Dictating machine control unit
10/24/1978US4122300 Data transmission system and application thereof to the transmission of analog signals and of data in a network with delta modulation
10/17/1978US4121060 Touch button switch for dictation handset
10/17/1978US4121053 Telephone command apparatus
10/10/1978US4119815 Central station system including secondary communication path established through commercial telephone network
09/1978
09/26/1978US4117277 Arrangement for simultaneous two-way data transmission over two-wire circuits
09/26/1978CA1039420A1 Detector for coded speech signals
09/19/1978CA1038979A1 Transponder for transmitting data from digital encoding transducers over a telephone line
09/19/1978CA1038978A1 Alarm and utility meter reading system employing telephone lines
09/12/1978US4114139 Security controlled information exchange system
09/12/1978US4113986 Telephone controlled lock release arrangement
09/12/1978US4113985 Mine dial and page phone system
08/1978
08/15/1978US4107473 Two-way paging system transmission direction sensing and control apparatus and method
08/15/1978US4107467 Electronic order placement system using signals over telephone line
08/15/1978US4107466 Individual room energy control system
08/15/1978CA1036504A1 Multiple-channel dictate station apparatus with automatic release of selected channel
08/01/1978US4104486 System for accumulating data over nondedicated telephone lines
07/1978
07/18/1978US4101833 Duplex data transmission modem utilizing an injected tone for shifting power within the transmit spectrum
07/18/1978US4101743 Test circuit for a protective coupler
07/11/1978US4100375 Telephone, intercom and remote control system
06/1978
06/27/1978US4097696 Method and apparatus for polling security alarm installations
06/27/1978US4097694 Time-division telephone system embodying trunks having demodulating-adder circuits
06/27/1978US4097690 Intercommunication and alarm telephone system
06/20/1978US4096524 Television receivers
06/13/1978US4095277 Method for communicating text commands and instructions using conventional coded text characters and a structure for decoding and presenting command and instruction signals
06/13/1978US4095050 Monitor and control system
06/06/1978US4093825 Data transmission system
05/1978
05/09/1978US4088844 Telephone station set interface circuit
05/09/1978US4088838 Voice response system
05/02/1978US4087638 DTMF Communication system
05/02/1978US4087635 Method of and system for carrying out calculations by means of a telephone set
04/1978
04/25/1978US4086434 Remote condition reporting system
04/18/1978US4085449 Digital modem
04/18/1978US4085292 Combination alarm and automatic telephone answering system
04/04/1978US4083039 Voltage enhancement circuit for central station monitored alarm systems
04/04/1978US4082921 Automatic subscriber interrogation system
02/1978
02/21/1978US4075659 Electronic door announcer
02/21/1978US4075426 Parallel silent communicator
02/07/1978US4072986 Message synthetizer
02/07/1978US4072825 Hotel/motel automatic control system
02/07/1978US4072824 Automatic dialer for paging system or the like
01/1978
01/31/1978US4071716 Dictation system
01/31/1978US4071698 Telephone system for audio demonstration and marketing of goods or services
01/31/1978US4071697 Interactive video/telephone transmission system
01/24/1978US4070669 Anti-fraud alarm transmission line security system
01/24/1978US4070554 Digital testing and power control in a digital communication system
01/24/1978US4070549 Remote location electronic actuator and system that includes the same
01/17/1978US4069396 Power saving circuit for use with a converter circuit in a telephone switching installation
01/10/1978US4068097 Remote monitoring system
01/10/1978US4068096 Pressure monitoring system
01/10/1978US4068092 Voice control circuit
12/1977
12/27/1977US4065642 Message signaling and alerting system and method thereof
12/20/1977US4064368 Closed-loop emergency alarm and response system
12/06/1977US4061977 Phase tracking network
11/1977
11/22/1977US4059727 Data transmission system between telephone subscriber location and telephone exchange location during idle telephone condition
11/08/1977US4057690 Method and apparatus for detecting the presence of a speech signal on a voice channel signal
11/01/1977US4056684 Surveillance system
10/1977
10/25/1977US4055729 Apparatus for the direct connection of ancillary equipment to a telephone network
10/18/1977US4054752 Cash register protection recording and alarm system
09/1977
09/27/1977US4051327 Telephone alarm system
09/13/1977US4048621 Coding system for an alarm system and the like
08/1977
08/23/1977US4044351 System monitor with innate line security ability
08/09/1977US4041249 Central dictation system with privacy signal used for transcribing scanning
08/09/1977US4041242 Telephone signalling system having interruption preventive means
08/02/1977US4039751 Method and apparatus for closed loop testing of first and second modulators and demodulators
07/1977
07/19/1977US4037059 Intercom system for a key telephone system
06/1977
06/21/1977US4031329 Time limited telephone paging employs a relay switch actuated by dual frequency tone
06/21/1977US4031322 Telephone operated signalling system
06/07/1977US4028688 Refrigeration unit air temperature detection alarm system
06/07/1977US4028493 Call progress signal detector
05/1977
05/31/1977US4027103 Burglar alarm improvements
05/24/1977US4025730 In-band signal receiver
05/17/1977US4024345 Audio program and telephonic communication system
05/10/1977US4022977 Automatic meter-reading and controlling system
05/03/1977US4021615 Apparatus for conserving energy in a building
04/1977
04/26/1977US4020287 Telephonic troubleshooting circuit for electric motor drives
04/12/1977US4017686 Telephone line voltage actuated switches
04/05/1977US4016360 System for remotely checking equipment
03/1977
03/22/1977US4013844 Line circuit for a universal key/internal telephone system
03/22/1977US4013838 Telephonic enquiry system
03/15/1977US4012599 Telephone communications system for the deaf
03/15/1977US4012595 System for transmitting a coded voice signal
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