Abstract: A passive infrared detection and conversion circuit includes a pyrosensor, a current amplifier, a capacitor, and a signal processor circuit. The signal processor is operable to charge the capacitor to a first voltage level and to measure a capacitor discharge time, the time required for the capacitor to discharge from the first voltage level to a second voltage level. The signal processor is further operable to generate an electrical control signal responsive to a variation in the capacitor discharge time which corresponds to a significant motion event. When the pyrosensor is exposed to infrared motion, it generates a transient current, and the capacitor discharge time corresponds to the transient current. The signal processor circuit includes logic operable to compare the capacitor discharge time with a long-term average capacitor discharge time.

Abstract: A passive infrared motion detector with a 360.degree. field of view. The motion detector includes an integrated-circuit infrared sensor package containing an infra-red sensor having one or more sensing elements. The integrated-circuit sensor package is provided with viewing windows on both sides and the sensing elements are mounted within the integrated-circuit package so that both sides of the sensing elements are able to receive infrared radiation through the viewing windows from the areas in front of and behind the integrated-circuit package. The motion detector includes infrared-reflecting means that are disposed with respect to the front and rear surfaces of the sensing elements so as to reflect radiation to the surfaces from lateral areas on both sides of the integrated-circuit package.

Abstract: A motion sensor having front and rear fields of view includes a housing containing an infrared sensor mounted on a surface which may be a circuit board containing associated electronics to form the motion detector which produces an output in response to the motion of a warm body passing through the sensor's field of view. A front part of the housing is provided with a forward looking optical system, preferably a multifaceted Fresnel lens, and a rear part of the housing is provided with at least one rearward looking optical system. A reflector is provided directly between the sensor and the forward looking optical system for reflecting infrared light entering the rearward looking optical system onto the detector. According to one embodiment of the invention, the rearward looking optical system includes a pair of Fresnel lenses and the reflector is a flat mirror.

Abstract: A motion sensor assembly has a housing with an opening therein, an infrared detector, a lens which may be of the Fresnel type, a holder, a circuit, and a transformerless direct current power supply that provides power to the circuit and detector. The housing has an interior space bounded by at least one wall. The opening is formed in the wall. The holder receives and secures both the lens and the detector so that the lens focuses a field of view on the detector. The holder also orients the detector and lens so as to reduce internal reflections between the lens and detector. The holder further mounts both the lens and the detector adjacent the opening in the wall. A radiation permeable covering disposed in the opening conceals the elements of the assembly within the interior space of the housing. In one embodiment, the radiation permeable covering includes louvers.

Abstract: A passive infrared motion detector with a 360.degree. field of view. The motion detector includes an integrated-circuit infrared sensor package containing an infra-red sensor having one or more sensing elements. The integrated-circuit sensor package is provided with viewing windows on both sides and the sensing elements are mounted within the integrated-circuit package so that both sides of the sensing elements are able to receive infrared radiation through the viewing windows from the areas in front of and behind the integrated-circuit package. The motion detector includes infrared-refracting means that are disposed with respect to the front and rear surfaces of the sensing elements so as to direct radiation to the surfaces from lateral areas on both sides of the integrated-circuit package.