Abstract: An LC oscillation-based magnetic lock is described, which mainly includes an electromagnet set having an E-type iron core and a magnetic field generating coil set, and an armature plate. The electromagnet set and the armature plate are installed on a door panel and a door jamb, respectively. By means of the attractive or repelling force between the aforementioned each other, and by controlling the magnetism of the electromagnet set, the door panel is caused to be opened or closed. The LC oscillation-based circuit being a coil set disposed nearby the magnetic field generating coil set and oscillating in an oscillation frequency when an inductance variation has occurred, the oscillation frequency is then corresponded to the inductance variation; and a control circuit is to determine an open/close state of the door panel according to the oscillation frequency calculated.

Abstract: An electronic lock includes a housing, a solenoid, a lock bar, a solenoid cover, and a faceplate. The solenoid is received in and mounted to the housing and the solenoid has a retractable rod being spring biased to a first position when the solenoid is not energized and magnetically moved to a second position when the solenoid is energized. The lock bar is pivotably mounted to a pivot pin, and the pivot pin is mounted with a spring member and fixed to two ends of the housing. The solenoid cover is covered on the solenoid and the faceplate is mounted to the housing. The solenoid cover and the faceplate define a latch bolt cavity. When the solenoid is energized, the retractable rod is withdrawn to the second position, so that the lock bar can be transversely rotated, thereby detaching from a latch bolt and allowing a door to be opened.

Abstract: A demagnetizable electromagnetic door lock is actuated by generating or degenerating magnetic force of an electromagnetic coil. A magnetic field direction driving circuit is electrically connected to the electromagnetic coil. Under the control of a controller, after the magnetic field direction driving circuit is applied to eliminate the residual magnetic force of the electromagnetic coil, the door lock can work smoothly in due course.