Intercom. system with amplifiers compensating for line loss - uses voice signals to switch in voice-direction amplifier and to disable opposite direction amplifier

摘要

The intercommunications system has amplifiers to eliminate line losses. Each voice direction has its own amplifier switched on by the voice signal or by an AF signal while the amplifier for the opposite direction is simultaneously disabled. The voice frequency or AF signal is amplified, rectified and presented to the input of a relay that switches on the amplifier in the direction of the voice signal and disables the amplifier in the opposite direction.