| 摘要 |
The device comprises a storage battery B and an inverter I which can supply the motor M of the lift 2 with an alternating voltage or a system of alternating voltages such as to enable the motor M to operate at low speed in order to return the car 3 to one of the two levels between which it stopped when the normal supply to the motor M failed. A detector device R supplies an electrical signal indicative of the intensity of the current absorbed by the motor M. The control unit ECU analyses the gradient of a portion of the signal which is indicative of the load condition of the motor M and sends to the inverter I drive signals which, in dependence on the result of the analysis of the gradient, may reverse the sense of rotation of the motor M. <IMAGE> |
