The Infrared PIR (Passive Infrared) Motion Sensor Switch DIY Soldering Kit is a practical project for hobbyists, students, and engineers to explore motion-sensing technology. This kit provides hands-on experience in assembling a fully functional motion sensor switch capable of detecting human presence and controlling a relay based on movement within the sensing area. This kit is ideal for creating automatic lighting systems, security alarms, or other motion-activated devices. Features Fully automatic sensing: When a person enters the sensing range, the relay is triggered (the red LED lights up). After the person leaves, the relay will release automatically after a delay (the red LED turns off). Photoresistor control: (Not included in the kit; users can install a photoresistor of their choice.) The photoresistor can disable sensing during the day or in bright environments. Two trigger modes (set by jumper cap): a. Non-retriggerable mode: When the sensor detects motion and the relay is activated, the relay will release after the set delay time, regardless of further movement. b. Retriggerable mode: When the sensor detects movement, the relay stays activated. If there is continuous movement within the delay period, the relay remains activated, and the delay resets. The relay only releases after no movement is detected, plus the delay time starting from the last movement. Parameters Operating Voltage: 4.5 – 5V Standby Current: 65µA Operating Current: 40mA Load Power: ≤ 300W Block Time: 2.5 seconds Delay Time: 4 – 300 seconds Trigger Modes: L: Non-retriggerable H: Retriggerable Sensing Range: Less than 120° cone angle, adjustable within 5 meters Operating Temperature: -15°C to +70°C Lens Diameter: 24mm Sensor PCB Dimensions: 27 × 27 mm Control PCB Dimensions: 40 × 60 mm Notes If you choose a version with a photoresistor included, do not install the photoresistor immediately. Test the module first to ensure it works normally. Install the photoresistor only after verifying normal operation, as the module requires a dark environment to function properly once the photoresistor is installed. During the first power-up, the sensor needs around 1 minute to initialize. During this time, the relay will engage and release about three times before entering standby mode and becoming operational. For initial use, set the delay potentiometer (VR2) to the minimum (MIN), and the distance potentiometer (VR1) to the maximum (MAX) to test the module’s functionality. Avoid direct light interference on the lens from nearby sources like lamps to prevent false triggers. Also, avoid placing the module in areas with moving air, as wind can interfere with detection. Positioning tips: Align the sensor window parallel to the direction where human activity is most frequent. To enhance the sensing range, a lens can be added to the front of the sensor. Note that the sensor’s sensitivity is stronger on the left and right sides compared to the top and bottom directions.
