摘要 |
An active, relatively high gain, low power consuming band pass filter circuit centered at approximately 6 KHZ and having a pass band of 100-200 HZ. In a disclosed glass breakage sensor, the filter couples sensed ambient sounds of breaking glass to associated detection, driver and annunciator means. Signals of appropriate duration and frequencies indicative of breaking glass are thereby monitorable to define and induce an alarm condition within a security system.
|