Monitoring system for person in possible danger - includes transmitter which sends coded signals which are received and evaluated at central station

摘要

The person carries a monitoring device with a transmitter sending radio signals received by a central monitoring station. When a release device is operated, coded radio signals are transmitted, received in the central station and applied to an evaluator which checks the coding, and, if correct, emits an optical and/or acoustical signal. A different warning or alarm signal is given when the coded radio signal is not received during a fixed adjustable period. The circuit components include a pulse generator (1), frequency divider (2), coder (3), modulator (4) and HF transmitter (5). The pulse generator, in one embodiment of the device, is stimulated by a trigger (6) connected with a contact (8) by a cable (7). Another embodiment includes a timer (11), control unit (12) alarm (13) and optical signal unit (14).