Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Nippon Telegraph and Telephone Corp
Original Assignee
Nippon Telegraph and Telephone Corp
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Nippon Telegraph and Telephone CorpfiledCriticalNippon Telegraph and Telephone Corp
Priority to JP16175381ApriorityCriticalpatent/JPS5862996A/ja
Publication of JPS5862996ApublicationCriticalpatent/JPS5862996A/ja
Publication of JPS6137838B2publicationCriticalpatent/JPS6137838B2/ja
H04M1/00—Substation equipment, e.g. for use by subscribers
H04M1/26—Devices for calling a subscriber
H04M1/30—Devices which can set up and transmit only one digit at a time
H04M1/50—Devices which can set up and transmit only one digit at a time by generating or selecting currents of predetermined frequencies or combinations of frequencies
Landscapes
Engineering & Computer Science
(AREA)
Signal Processing
(AREA)
Sub-Exchange Stations And Push- Button Telephones
(AREA)