Electronic unit warning of loss of item, e.g. handbag, has radio-based separation measurement device issuing alarm in response to received signal level

摘要

An electronic warning unit has transmitter (1) and receiver units with activation knobs (3) and a status light (4). When the received signal strength falls below a threshold value, indicating separation of receiver and transmitter, an acoustic or vibration alarm is generated. The system may be preset to sound when the two parts are separated by more than a small distance such as 1.5 metres.