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.)
Siemens Brothers and Co Ltd
Original Assignee
Siemens Brothers and Co Ltd
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 Siemens Brothers and Co LtdfiledCriticalSiemens Brothers and Co Ltd
Application grantedgrantedCritical
Publication of FR700547ApublicationCriticalpatent/FR700547A/fr
H04Q1/00—Details of selecting apparatus or arrangements
H04Q1/18—Electrical details
H04Q1/30—Signalling arrangements; Manipulation of signalling currents
H04Q1/44—Signalling arrangements; Manipulation of signalling currents using alternate current
H04Q1/444—Signalling arrangements; Manipulation of signalling currents using alternate current with voice-band signalling frequencies
H04Q1/45—Signalling arrangements; Manipulation of signalling currents using alternate current with voice-band signalling frequencies using multi-frequency signalling
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Engineering & Computer Science
(AREA)
Computer Networks & Wireless Communication
(AREA)
FR700547D1929-07-291930-07-15Perfectionnements aux systèmes téléphoniques
ExpiredFR700547A
(fr)