| 摘要 |
<p>The invention relates to a warning method and device meant for the acoustical signalling of robbery. According to the invention, the method detects when a protected object is relatively moved away from its owner, by using a customized device which is protected against detection-proof means and meant to acoustically warn when a preset distance between the owner and the protected object is exceeded, while allowing the accurate and convenient localization of the protected object. The claimed device operates as follows: an emitter (1) generates an electromagnetic field which is modulated with customizing code sequences and received by a receiver (2) tuned with the emitter (1), the signal being processed by the receiver (2) for determining the field quenching depending on the relative distance between the receiver (2) and the emitter (1), and depending on the result, if the distance between the emitter (1) and the receiver (2) exceeds a preset value, or if the received signal is a jamming signal, the receiver (2) proceeds to the identification of the code sequence and to the acoustic warning.</p> |
