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.)
Nokia Spain SA
Original Assignee
Alcatel Espana SA
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Filing date
Publication date
Application filed by Alcatel Espana SAfiledCriticalAlcatel Espana SA
Publication of ES295545A1publicationCriticalpatent/ES295545A1/en
An asymmetric direct current signaling system comprising a number of subscriber apparatuses each connected on two wires to a common exchange, said subscriber apparatuses comprising transmission means by push buttons for selectively grounding said two wires as a start signal and for simultaneously indicating selected key signals comprising said central means receiving start signal signals in response to said start signal, key signal receiving means connected to said two wires acting in response to the operation of said signal receiving means. starting to successively apply a first and a second potential of opposite polarity to said two wires, rectifying means associated with said transmission means in said subscriber apparatuses for coupling and decoupling said two wires in response to the polarity of said interrogation potential to form said s selected key signal and means in said key signal receiver to receive and register said selected key signal. (Machine-translation by Google Translate, not legally binding)
ES0295545A1963-01-311964-01-21Signaling system (Machine-translation by Google Translate, not legally binding)
ExpiredES295545A1
(en)