Analysis of LED lighting fixtures and sensor technology 5

The longitudinal oscillation characteristics of ultrasound can propagate in gases, liquids, and solids at different speeds; It also has refraction and reflection phenomena. When it propagates in air, its frequency is lower and it decays faster, while in solids and liquids, it decays less and propagates further. Ultrasonic sensors utilize these characteristics of ultrasound. Ultrasonic sensors have the characteristics of a large sensitive range, no visual blind spots, and are not affected by obstacles. This technology has been used in commercial and security fields for more than 25 years and has been proven to be the most effective method for detecting small object motion. Therefore, the system composed of LED lamps can sensitively control the switch.diode

Figure 8: Application scheme of ultrasonic sensor and microprocessor diode

Due to the high sensitivity of ultrasonic sensors, air vibrations, ventilation, heating, and cooling systems, as well as movements in adjacent spaces, can cause false triggering of ultrasonic sensors. Therefore, ultrasonic sensors need to be calibrated in a timely manner. Table 1 compares the performance of infrared PIR sensors and ultrasonic sensors.diode

Table 1: Performance Comparison between Passive Infrared Sensors and Ultrasonic Sensors  diode