摘要:
Process and device for controlling the drive of a conveyor system (10), specifically in the form of an escalator or passenger conveyor, which can be switched from load to no-load operation, comprising a drive motor (26) and a variable frequency converter (42), which is at least controllable with respect to the frequency of its output voltage, wherein, under load, the drive motor (26) is supplied with a line voltage with an essentially constant line frequency and, at no-load, is supplied the output voltage of the variable frequency converter's (42), wherein, prior to a changeover from no-load to load operation, the output frequency of the variable frequency converter (42) is essentially brought with phase accuracy to the line frequency by means of a PLL device (30), and wherein this changeover is brought about as soon as this phase conformance has been realized.
摘要:
An elevator car (2) comprises a cover (14; 40) extending over at least a portion of the top surface of the car (24). The cover (14; 40) is mounted on a resilient support (28, 42). The car (2) further comprises means (32; 44) for detecting displacement of the cover corresponding to the weight of a person being applied to the cover. If such displacement is detected, normal operation of the car (2) is prevented.
摘要:
An elevator system includes an electronic driver which transmits a multi-phased electric current through a relay to a motor driving an elevator car. Under normal operating conditions, the motor uses the current from the driver to move the elevator car in a hoistway. When electric power fails, the elevator car is moved by gravity for any necessary rescue or maintenance operations, and consequently moves the motor. The movement of the motor generates a multi-phased electric current therein. The generated current is utilized to power a display panel of a movement indicator, which is automatically connected to the motor by the relay when power fails in the elevator system. The powered display panel informs the operator of the direction and speed of travel of the elevator car.