The elevator is driven by an electr

The elevator is driven by an electric motor. The first escalator appeared in 1900. But in 1949, group control elevators began to appear and put into use. Then in 1955, a minicomputer for controlling elevators appeared (the development of elevators began with the actual elevator, vacuum tube, designed and manufactured by Otis (Otis) in 1889). In 1967, thyristors were applied to elevators, which greatly improved the performance of elevators and greatly simplified the driving system of elevators. Since 1976, microprocessors have been used to control elevators, which makes the electrical control of elevators more convenient and can meet the changing needs of people. Since then, elevators have entered a new period of development. The development of elevator control technology has gone through three stages: relay control stage, microcomputer control stage and field bus control stage.