Abstract: A drive control unit for a hydraulic elevator comprises: an inverter for variably driving the motor; a speed detector for detecting a rotating speed of the motor; a current detector for detecting a primary current of the motor; a speed control, unit for calculating a torque command value to the motor according to a deviation between the rotating speed detected by the speed detector and a speed command value; a torque control unit for controlling the inverter according to the rotating speed detected by the speed detector, the primary current detected by the current detector and the torque command value calculated by the speed control unit; a pump pressure detector for detecting the pump pressure of the hydraulic pump; a limiting means for limiting the torque command value output from the speed control unit when the pump pressure, detected by the pump pressure detector, decreases below a set value.

Abstract: A control device for an elevator which automatically regulates an offset to correct the offset amount contained in a control signal applied to the base circuit of an inverter for driving the hoisting motor of the elevator with a regulator for generating the control signal to detect the output current of the inverter while the elevator is stopped to operate to correct the current to a predetermined value or lower, thereby holding the corrected value even during the operation of the elevator.

Abstract: An elevator speed control device in which the cage of the elevator can be stopped at a desired floor with a high accuracy without increasing the capacity of power supply equipment to compensate for periods of low AC source voltage. A detecting circuit produces an output signal in response to the generation of a deceleration instruction signal. This signal is converted into a short duration pulse signal which is used to set the output of an integrator included in the control circuit loop to a predetermined value.