Combination infrared microwave intrusion detector.

摘要

The independent outputs of the microwave system (26) and the passive infrared detector (28) are processed separately in electronic circuits so that there will be no final alarm output signal unless both systems are activated by the radiation of a moving target. A time-AND gate is used to combine the signals and generate an alarm. The upper portion (12) of the housing includes a circular well wall and ribs which radiate from the well wall and the lower portion of the housing includes a circular well wall and a coaxial circular wall. The bottom edge of the printed circuit board (PCB) of the detector butts against the upper edge of the ribs and a portion of the PCB bears against the circular well wall while the upper edge of the PCB butts against the upper edge of the circular wall and a portion of the PCB bears against the well wall formed in the upper housing. The PCB also engages a swivel ring (18) which is rotatable with the housing and which includes notches engageable with a protection extending from the inner surface of the lower housing.