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
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 Alcatel Espana SAfiledCriticalAlcatel Espana SA
Publication of ES426724A1publicationCriticalpatent/ES426724A1/es
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
H04M1/31—Devices which can set up and transmit only one digit at a time by interrupting current to generate trains of pulses; by periodically opening and closing contacts to generate trains of pulses
H04M1/312—Devices which can set up and transmit only one digit at a time by interrupting current to generate trains of pulses; by periodically opening and closing contacts to generate trains of pulses pulses produced by electronic circuits
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Engineering & Computer Science
(AREA)
Signal Processing
(AREA)
Exchange Systems With Centralized Control
(AREA)
ES426724A1973-05-291974-05-29Un aparato telefonico de botonera.
ExpiredES426724A1
(es)
Una disposicion de circuito para una instalacion de telefonia con transmisores de numero de llamada para la recepcion de numeros caracteristicos cortos.
Perfeccionamientos en dispositivos para seleccionar automa-ticamente una conexion de abonado telefonico y dar paso a una senal de alarma al accionarse un interruptor de alarma.