Directions for Use
1. Circuit design
(1) The connection between PIR and other devices should be as short as possible. On the double-panel or multi-layer board, try not to trace the line below the connection, especially the high current trace.
(2) The circuit of the PIR part should be made as a separate PCB board to avoid interference. If all circuits are on the same board, the PIR part should be isolated and has a separate grounding. And the PIR parts can only connect with other circuits through the positive, negative and output three wires.
(3) PIR VDD is grounded to the capacitance of 100NF and the capacitance should be as close as possible to the VDD of PIR.
2. Application Note
PIR is a pyroelectric infrared sensor that detects changes in infrared rays. When detecting a heat source other than the human body, or if there is no temperature change or movement of the heat source, detection is not workable. Pay attention to the following matters that may affect the PIR’s detection performance.
(1) Heat source other than Human Body
1) small animals enter the detection range
2) Far-infrared directly shoot sensors such as sunlight, car headlights, incandescent lamps, etc.
3) The temperature of the detection range changes drastically due to the warm air of the cold greenhouse equipment, the cold air, or the water vapor of the humidifier.
(2) When it is difficult to detect the heat source
1) When there is a material such as glass or acrylic that is difficult to transmit far infrared rays between the sensor and the detected object.
2) The heat source in the detection range hardly moves, or moves at high speed.
(3) Cautions for use
1) When stains are attached to the window, the detection performance will be affected, so please be careful.
2) The lens is made of a weak material (polyethylene). When a load or impact is applied to the lens, it will cause deformation and damage, thereby affecting the detection performance. So please avoid the above situation.
3) Damage may be caused when static electricity of ±200V is applied. Therefore, please pay attention to the operation, avoid touching the terminal directly by hand.
4) When soldering the wire by hand, please make sure the soldering iron at a temperature of 350 ° C or less and finish the soldering within 3 seconds. When soldering through a solder bath, performance may deteriorate, so avoid it.
5) Please avoid cleaning the sensor. Otherwise, the cleaning liquid may intrude into the inside of the lens, which may cause deterioration in performance.
6) When using with cable wiring, to prevent interference, it is recommended to use shielded wires and shorten the length as much as possible.
7) Before test, be sure to install the Fresnel lens and the finished casing in advance. The sensor's iron shell and pins can not be exposed. Otherwise air blows might happen easily and the detection performance will be affected.
8) Each Fresnel lens has a fixed focal length. Please pay attention to the installation. If the focal length is not adjusted correctly, the sensitivity will be affected.