The design of the electromagnet in automatic door locks is the same as that of ordinary electromagnets. It utilizes the principle of generating a magnetic field by an electric current. When the electric current passes through the silicon steel for a moment, the electromagnetic lock will generate a huge suction force to firmly hold the adsorption iron plate, achieving the effect of locking the door.
Even a very small electric current can make the electromagnetic lock of the automatic door lock electromagnet generate a large magnetic force. Once the access control system that controls the power supply of the electromagnetic lock accurately identifies the personnel, it cuts off the power. Then the electromagnetic lock loses its suction force and the door can be opened. Since the electromagnetic lock does not have a complicated mechanical structure or a latch bolt structure, it is suitable for controlling the access of emergency exit doors or fire doors. Its interior is protected by pouring epoxy resin to protect the lock body. Currently, the suction strength of the electromagnetic lock is expressed in pounds (LB), and the testing method is static pressure application. The so-called static pressure application means that after the electromagnetic lock is energized, the pulling force on the adsorption iron plate is gradually increased slowly. When it exceeds the suction force of the electromagnetic lock of the automatic door lock electromagnet, the adsorption iron plate is suddenly pulled open, and this pulling force data is the pulling force value of the electromagnetic lock. Moreover, the acting force between the electromagnetic lock and the adsorption iron plate must be face to face and applied in a straight line (collinear load test), so that the suction force (Holding Force) of the electromagnetic lock can be relatively large. The adsorption iron plate may be temporarily magnetized due to being affected by the magnetic force of the electromagnet for a long time.
When the electromagnetic lock of the automatic door lock loses its suction force, the door can be opened.
The Working Principle of the Magnetic Lock
We know that each magnet has two poles, a north pole (N pole) and a south pole (S pole). Magnets have the characteristic that like poles repel each other and opposite poles attract each other. The magnetic lock precisely takes advantage of this characteristic of magnets. Lock-picking tools made of permanent magnets (magnetic beads) are manufactured. Some people also call it an "electronic lock". The design of the magnetic lock (or electromagnetic lock) is the same as that of the electromagnet. When the electric current passes through the silicon steel for a moment, the electromagnetic lock of the automatic door lock electromagnet will generate a huge suction force to firmly hold the adsorption iron plate to achieve the effect of locking the door. With just a small electric current, the electromagnetic lock will generate a huge magnetic force. Once the access control system that controls the power supply of the electromagnetic lock accurately identifies the personnel, it cuts off the power and the electromagnetic lock loses its suction force.
