| 摘要 |
The structure-borne sound detector contains a sensor for picking up structure-borne sound and an electronic evaluation system connected to the latter. The electronic evaluation system has a comb-filter circuit which comprises two comb filters arranged in parallel and of mirror-image construction and whose outputs are fed to a minimum stage. From the minimum stage only the smaller of the output signals of the two comb filters is supplied in each case for further processing. Unwanted signals situated in the frequency range of the typical structure-borne sound vibrations generated during a break-in attempt can be reliably suppressed by the comb-filter circuit and false alarms consequently prevented.
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