The Jotron (PHONTECH) BTS 4000 system is an emergency telephone system without the requirement for any external power supply.
All energy required for 6-9 minutes of continuous operation is produced by the call generator.
The system is equipped with a sophisticated, extremely low power amplifier with high power and low distortion output. The amplifier is integrated in one of the telephone units to reduce the installation cabling.
The system may also be connected to an external 24 V DC power supply to ensure continuous operation under normal conditions.
The system automatically switches to batteryless and emergency operation in case of mains power failure.