Emergency call branch transmitter - is connected through main switch as extension to public telephone network

摘要

The circuit arrangement comprises a telephone terminal jack (1) connected with a main button switch (2), call number automatic response unit (3), miniature tape recorder (4), parallel set of push buttons (5), speaker control switch (6) and loudspeaker (7). When one of the several push-buttons (5) is operated, the automatic transmitter for an emergency call is started, and then the miniature tape recorder (4) with a short endless tape loop. A prerecorded message and address are then repeatedly transmitted through a magnetic head and an amplifier. The system may be used to transmit emergency messages to the police without the need for actual speech delivery through the normal public telephone receiver.