CONTROLLER OF ELECTRIC/HYDRAULIC SERVO MECHANISM

摘要

PURPOSE:To prevent the transistor of an output circuit from being broken and a battery from being reduced in its potential by putting a servo mechanism in the inoperative condition when the driving engine of a hydraulic pump makes no running operation. CONSTITUTION:A change-over device 32 is disposed between the operation circuit 13 and the output circuit 14 of a controller 31. The output circuit 14 controls both solenoid valves 10 and 11 which control oil pressure transmitted to a servo cylinder 7. The change-over device 32 is operated by the signal relating to revolutional speed N of an engine 2. When the engine 2 is in stop, the change- over device 32 cuts off the connection to the output circuit 14. The change-over device 32, instead, makes connection to the output circuit 34 which actuates indicators 33A and 33B such as Diodes. In short, if the engine 2 is in stop, the output signal from the operation circuit 13 triggers both the indicators 33A and 33B to inform said state of the engine.