Abnormal analysis of gate system

Does the car pass?
1. Is the vehicle detector wiring correct (1, 2 to 220V power supply; 7, 8 grounding inductance coil; 3, 4 connection gate main board signal interface);
2. When there is no car, the signal light of the vehicle detector will be on (it will ind

Direct-acting solenoid valve

For our oil purifier, we often involved in how to use the solenoid valves in the oil purifier system. There are the Recoil types, Pilot type, Direct-acting types, etc. So we need to know the function and

What is the free handle of the smart lock?

The so-called free handle in the fingerprint lock is actually the handle will become free after unlocking with the correct unlocking method, while the free state means the state of being unstressed, although the handle is still level with the ground, but if the handle is held down The pressur