Security door working principle analysis!
2018-04-29 15:00:45
It is a detection device for detecting whether a person carries a metal object, and is also called an Archway metal detector.
The principle of the security gate is a 3.5-4.95M sinusoidal oscillation generated by a crystal oscillator. A sine wave of about 7.6K is divided by a frequency divider. After the power amplification by the transistor and the coil, electromagnetic waves are emitted from the large input coil of the door (7 zones). The 1-6 zone coils are received separately. After receiving, the received signal is compared with the reference signal. After the change is found, the output level of the acquisition card is changed. The CPU scans the data of the six area acquisition cards in 280 milliseconds to determine the location of the metal and output the display.
Second, the structure 1, the door structure: consists of a large coil, 6 small coils, compensation coils and graphite. 2, chassis structure security door
Third, when the detection workflow CPU detection → a group of infrared blocked → detect whether the acquisition card data changes → alarm → detect another set of infrared → reset re-probing.