HYDRAULIC CONTROLLER FOR CARGO

摘要

PURPOSE:To prevent the stepping out of a stepping motor by keeping constant a torque generated in the stepping motor. CONSTITUTION:This hydraulic controller has a CPU 12 into which an operating amount of a cargo lever 1 detected by a potentiometer 2 is inputted through an A/D converter 15. The CPU 12 controls a stepping motor 9 pivotably through a motor driving circuit 17 on the basis of the operating amount of the cargo lever 1 to control the positioning of a spool 8 for a control valve 5. The change of a voltage supplied to the stepping motor 9 is inputted into the CPU 12 through a voltage detection circuit 16. The CPU 12 pivotably controls the stepping motor at a driving frequency corresponding to the detected voltage so that a torque generated in the stepping motor 9 is kept constant, thereby preventing the stepping out of the stepping motor 9.