How PIR Sensor Module ZRD-09 Winsen Works
Passive infra-red (PIR) motion detectors used in security systems are basically heat radiation detectors, sensing the motion of a heat source (infra-red radiation) to detect an intruder. They have a photo-diode that is sensitive to the heat radiation frequencies emitted by the human body, and a special lens that looks at 20 - 30 narrow fields within the protected space. They 'see' the temperature of the background, and any rapid change to this temperature is considered to be a suitable trigger. A person (or animal) moving in the space will move in and out of the fields of view, giving infra-red images to the detector in a rapid 'now you see me, now you don't' pattern.
This generates a series of pulses in the photo-diode as the heat source moves into and out of the fields of view of the PIR lens system. Even if part of your body is at the same temperature as the background, other parts will be at different temperatures, and will probably be detected. (Your head is hotter, your hands are cooler.) Slow changes in the infra-red signature of the room are ignored, as are single pulses, which may be environmental changes (air conditioners) or electrical noise (RFI).
Our PIR Motion sensor module description as below:
Pyroelectric infrared sensor module adopts high performance PIR sensor, Fresnel lens, Pyroelectric dedicated chip and High-performance voltage regulator circuit. It has the features, as low static power consumption, wide operating voltage, and high sensitivity. It has repeatable and non-repeatable trigger terminal to be selected, thus this module can be set according to the actual demand, convenient to use.
Two trigger modes;
Induction blocking time;
Human body induction toys,
Human body induction lamps, switches, and appliances
Industrial automatic controlling
Technical parameters :
||High Level, 3V; Low Level, 0V
||Default as 4S
||100°(Depend on the Lens)
||-10℃ ~ +70℃
|Fresnel Lens Size