Human body sensor light, also known as human body infrared sensor light or human body movement sensor light, is an intelligent lighting device that can automatically light up when the human body approaches and automatically turn off after the person leaves. This kind of lamp is not only convenient and practical, but also can effectively save energy, so it has been widely used in many places, such as corridors, stairwells, bathrooms, etc. So, how does the human body sensor light achieve this function? Below we'll explore how this works in detail.
1. Infrared radiation and human body induction
The core principle of the human body sensor lamp is to use the infrared radiation emitted by the human body to achieve sensing. Infrared radiation is a type of electromagnetic wave with a wavelength between visible light and microwaves. As a warm-blooded animal, the human body continuously emits infrared radiation, which forms a special "thermal image" around the human body. The infrared sensor built into the human body sensor lamp can capture this infrared radiation and thereby sense the presence of the human body.
2. Working principle of sensor
Infrared sensors in human body induction lights usually use pyroelectric effect or passive infrared detection technology. The pyroelectric effect means that certain crystals generate charges when their temperature changes, thereby enabling the detection of infrared radiation. Passive infrared detection technology achieves sensing by detecting the difference in infrared radiation between the human body and the background. When the human body moves, it will destroy the original infrared radiation balance and be captured by the sensor.
3. Circuit and control system
The work of human body sensor lights also requires the support of circuits and control systems. When the infrared sensor detects infrared radiation from the human body, it sends a signal to the control system. The control system determines whether the lamp needs to be lit based on the received signal. If it is judged that it needs to be lit, the lamp will be driven to emit light through the circuit; if it is judged that it does not need to be lit, the lamp will remain off. At the same time, the control system will also adjust the brightness of the lamps according to factors such as ambient light to achieve energy saving and comfort.
4. Delay and sensitivity adjustment
In order to better adapt to the needs of different occasions, human body sensor lights usually also have delay and sensitivity adjustment functions. The delay function can keep the lights on for a period of time after people leave, making it easier for people to find the exit or perform other operations. The sensitivity adjustment function can adjust the sensor's perception range of human body infrared radiation to adapt to different environments and usage needs.
