CONTROL SWITCHING DEVICE

摘要

PROBLEM TO BE SOLVED: To reduce the fluctuation of pump rotation speed control signals or the like and to prevent erroneous operations at the time of performing changeover from automatic control to manual control in pump rotation speed control or the like by comparing output for the automatic control and the output for the manual control and performing automatic/manual changeover only when the difference of both is within a prescribed range. SOLUTION: At the time of performing the changeover from the automatic control to the manual control, changeover input to a manual/automatic switching circuit 8 is performed by an operator. Manual conditions are established by the input, the information is supplied to the respective manual conditions 12 and a comparison operation is started in respective rotation speed operation signal comparator circuits 10, 15 and 19 based on manual rotation number operation signals 5 and rotation speed operation signals 9. Then, in this device, the manual rotation speed operation signals 5 and the rotation speed operation signals 9 are compared in a first rotation speed operation signal comparator circuit 10 and the changeover from the automatic control to the manual operation is performed in the manual/automatic switching circuit 8 only when an output difference is within the prescribed range, that is within an allowable value range.