In today’s world, it is necessary for high-rise residential or commercial buildings to equip with elevators for transporting people or freight vertically. The control system of an elevator is able to monitor the lift car’s position in real time when the elevator is moving ups and downs.

We have offered our Korean client a type of bi-stable position switch that is controlled by a magnet. When the magnet approaches from one direction and passes through the switch, the switch moves and maintains the state after actuation. The switch doesn’t return to its initial state until the magnet reverses from the opposite direction. The product has the advantages of high reliability, long life, rapid response, no power consumption, easy installation, etc.

The client installed the bi-stable position switch in the elevator shaft of each floor, and the magnet on the lift car. When the lift car passes a specific floor, the corresponding switch controlled by the magnet would change the state, and the signal is fed back to the elevator control system. The system is then able to locate the floor of the lift car by collecting the state signals of position switches at each floor. The bi-stable position switch can maintain the state after the magnet passes through, and the sensing unit is designed as a passive device to maintain the switch state without power, therefore, it is still convenient to get the floor information without needing any calibration by resuming lift car back to the bottom or the top floor.  This improves stability and safety of the lifting system. In addition to floor positioning, these position switches can be used for deceleration and position-control of lift cars as well, enhancing the comfort of elevator operation.

Besides, the elevator door is also equipped with four bi-stable position switches provided by Misensor, which are the door-opening deceleration switch, the door-opening in-position switch, the door-closing deceleration switch and the door-closing in-position switch. By means of the cooperation of the mentioned four switches, the system can reasonably control opening and closing processes of the lift door so as to reduce collision and impact of it. At the same time, the system is able to monitor the state of the lift door to avoid safety accidents caused by improper operations.