Circuit of bilateral intercommunication (Machine-translation by Google Translate, not legally binding)

摘要

Bilateral intercommunication circuit characterized in that it comprises two communication circuits each of the caules includes two amplifiers connected in series to transmit in opposite directions, the first amplifier of each circuit being in the direction of the polarized communication normally to transmit and the second amplifier insufficiently polarized for said transmission and switching means that inject a direct voltage in the second amplifier of the first circuits sufficient to allow its transmission and a negative voltage in the first amplifier of the second circuits sufficient to block it in response to the appearance of a signal in the first amplifier of the first circuit. (Machine-translation by Google Translate, not legally binding)