The principle of electromagnetic lock is based on electromagnetic induction and magnetic force. When the electromagnetic lock is energized, the current flows through the coil of the electromagnet, creating a magnetic field. This magnetic field will attract the iron core, so that it is closely attached to the electromagnet. At this moment, the gap between the iron core of the electromagnetic lock and the lock body is filled, forming a complete magnetic channel. Because of the magnetic force, the latch is attracted and fits tightly with the lock body, thus realizing the locking function. When the electromagnetic lock is powered off, the magnetic field disappears, the iron core loses its attraction, and the locking tongue is no longer subject to the magnetic force. At this point, the latch can be moved freely under the action of external forces, thus opening the lock. Therefore, the electromagnetic lock can achieve the function of locking and unlocking by controlling the on-off current. In addition to the basic electromagnetic induction and magnetic effect, electromagnetic lock also uses a variety of technical means to improve its safety and reliability. For example, some electromagnetic locks will be equipped with anti-disassembly devices, when the lock is illegally removed, will trigger the alarm device, thus playing an anti-theft role. In addition, the electromagnetic lock can also be linked with other security systems (such as access control system, alarm system, etc.) to achieve more comprehensive security protection. Generally speaking, electromagnetic lock is a kind of lock based on electromagnetic induction and magnetic force, which has the advantages of fast locking and unlocking speed, safe and reliable, long service life, etc. , widely used in a variety of electronic access control system.