Improvements in devices to select automatically a telephone subscriber connection and give passage to an alarm signal when an alarm switch is activated. (Machine-translation by Google Translate, not legally binding)

摘要

Improvements in devices for automatically selecting a telephone subscriber connection and giving way to an alarm signal when an alarm switch is operated, of the type composed of a selector device equipped with an accumulator for the telephone number to be selected, which repeats several times the selection of the telephone number, and of an alarm signal emitter connectable to the telephone line, characterized in that the telephone line is linked with a selective amplifier that reacts to a certain frequency range and that on the one hand connects the signal emitter and on the other hand it disconnects the selector device. (Machine-translation by Google Translate, not legally binding)