Cloth Spreading/Cutting Machine Ngai Shing Development Limited , https://www.ngaishinghk.com
Explosion-proof infrared intrusion detector principle knowledge
Light travels in a straight line, hence the name "ray". If the path of light is blocked, the light is interrupted and the light cannot continue to propagate. The active light intrusion detector utilizes the linear propagation characteristics of light for intrusion detection. It consists of a light emitter and a light receiver. The receiver and the transmitter are installed separately, and a light warning line is formed between the transceivers. When the intruder crosses the warning, the intruder crosses the warning. When the line is blocked, the light is blocked, and the receiver loses its illumination and gives an alarm signal. In general, the infrared radiation outside the visible light spectrum is selected as the light source of the emitter, so that the intruder cannot detect the presence of the warning light. In order to avoid interference from natural sunlight, two technical measures are usually taken:
Explosion-proof infrared intrusion detector; add a color filter on the light receiving window of the receiver to filter other light;
Explosion-proof infrared intrusion detector; amplitude (intensity) modulation of the transmitter light, the specific method is: using infrared light-emitting diode as the light-emitting device of the emitter light source, and using the modulation signal with a frequency of several KHz, the power supply for the transmitter light source The voltage or current is modulated so that the intensity of the light emitted by the transmitter also changes according to the law of the modulated signal. In the receiver, an infrared receiving diode is used to receive the optical signal, and the signal is subjected to frequency selective amplification by an amplifier having a tuning loop, so that interference of other signals different from the frequency of the modulated signal can be filtered out, and sunlight is not modulated. The steady light, the signal it produces on the receiving diode, is naturally filtered out without responding.
The explosion-proof shell of this product is seamlessly welded with high-quality 4mm thick carbon steel or stainless steel. The surface is electrostatically sprayed after high-speed shot blasting, and the appearance is beautiful. The inside of the explosion-proof enclosure is suitable for installing the company's single beam, two beams, three beams, four. Beam infrared detector.