Human body microwave sensor radar technology LED light control

Human body microwave sensor radar technology is applied to LED lights to intelligently control lighting. Lighting is an indispensable part of modern human society, and lighting electricity accounts for about 19% of global electricity consumption. Therefore, green lighting has become an effective way and an important starting point for countries around the world to promote energy conservation and emission reduction, and mitigate climate change. Energy saving and emission reduction is the theme of today's social development.

LED is considered to be the green lighting source of the 21st century. LED (also known as Light Emitting Diode) is a solid-state semiconductor device that can directly convert electricity into light.

High luminous efficiency and low energy consumption. Under the same brightness, LED energy consumption is 10% of incandescent lamps and 50% of fluorescent lamps. The life of LED can reach 100,000 hours, which is 10 times that of fluorescent lamps and 100 times that of incandescent lamps.

In order to save land resources, modern buildings are generally equipped with underground parking garages. Due to the lack of light in the garage, the lights need to be on throughout the day.

However, low-light (low power consumption) lighting can be used to save electricity when there are no vehicles or people in and out of the parking lot. Therefore, the installation of human body microwave sensor radar technology LED lights in the garage can perform high-sensitivity detection of moving vehicles or people.

If people or vehicles enter or exit, the full power of the control lamp will continue to light. Until the person or vehicle leaves or stops moving, the lamp delays for a period of time, then turns into dim light (low power consumption) and continues to light. So as to achieve energy saving effect.

Radar technology is actually an electromagnetic wave between infrared and FM, with a frequency range of 300m-300gHz. The same as the speed of light, it transmits electrical signals through the air at a speed of C=29792458 m/s per second. Microwave mainly refers to its own electromagnetic wavelength of 1mm-1m, so it is called microwave. People still call it UHF electromagnetic waves.

The working frequency of the human body microwave sensor is generally fixed within the range of 5.8GHz plus or minus 75MHz. The process is as follows:

(1) Start-up - After the sensor is powered on, the oscillator circuit in the sensor will automatically generate a frequency of 5.8GHz plus or minus 75MHz, which we call the local oscillator frequency.

(2) Amplify the local vibration frequency as an electromagnetic wave carrier, and emit electromagnetic waves into the air through a high-frequency tube (or antenna).

(3) After the electromagnetic wave received and transmitted is reflected by surrounding objects, it is selected by the frequency selection network of the oscillator. Compared with the original 5.8G frequency, the difference signal is used as the basic signal for self-test (surrounding environment detection).

(4) When a moving object appears around, the reflected electromagnetic wave is analyzed by the circuit, which is different from the basic signal during self-checking. At this time, the signal is used as the basis of the trigger signal, and the module outputs the control signal.

The human body microwave sensor works at 5.8GHz, integrates radar transceiver, intermediate frequency circuit, MCU processing, etc. The periphery is matched with the antenna and a small amount of peripheral circuits to form a complete radar sensor, which can be used in various places such as supermarkets, schools, and home lights.

People started using touch to control light tubes. The working mode is: the finger touches the switch light on, and the circuit forces the delay 30S to turn off the light. Later, people felt it was inconvenient. They looked at voice-activated LED tubes. Working mode: When the sound light is detected, the sound disappears, and the light is turned off after a forced delay of 30S. However, voice control is easily affected by external noise, and then the infrared sensing LED light appeared, which solved the defect of voice control. However, infrared induction is easily affected by temperature, and the signal is easily attenuated during the transmission process, which affects the reception at normal distances.

The human body microwave sensor is transmitted by electromagnetic waves. Using the principle of Doppler effect and Fourier transform technology, the accurate high-frequency phase and frequency difference analysis system can accurately detect the high sensitivity of moving objects, whether it is a person or a vehicle, as long as it moves can be detected by the sensing device.

Human body microwave sensor radar sensing technology is one of the most advanced intelligent LED lamp product technologies. It can effectively reduce lighting power consumption, reduce energy waste, and achieve the purpose of energy saving and emission reduction.