Solenoids are widely used in smart locks. They are connected to the lock's circuit and control the lock by controlling the on-off of the current. When the circuit is energized, the solenoid produces a magnetic field and locks the door; when the circuit is de-energized, the magnetic field of the solenoid disappears, and the door can be opened.

The following are the advantages of solenoids in smart locks:

1.  Security: Solenoids are safe because they require electricity to generate a magnetic field and disappear when the electricity is turned off.

2.  Convenience: The control of solenoids is simple and can be controlled through the lock's circuit or smart phone software, making it easy to use.

3.  Reliability: Solenoids are reliable because they are not affected by the external environment and can operate stably for a long time.

Solenoids are widely used in smart locks, not only improving the security of the locks, but also the convenience and reliability of use.