JPS57193811A - Monitor controlling system - Google Patents

Abstract

PURPOSE:To make the operation easy, by providing a grip confirming switch for a handle of an operation switch and illuminating a display light on a monitored instrument corresponding to this operating switch when the operator grips the operating switch. CONSTITUTION:When the operator 1 grips an operating handle 7 and touches a touch button switch, the switch is connected to ground through the body of the operator 1 via an electrostatic capacitance to ground 21. A closed circuit consisting of a resistor 13, a resistor 16, a coupling electrostatic capacitor 23, the operator 1, the electrostatic capacitor to ground 21, and ground from an AC power supply 22 is formed, and a voltage V1 superimposing a prescribed DC voltage on an Ac voltage is applied across the resistor 16, i.e. to the gate of a field effect transistor, and an amplified voltage V2 is inputted to a Schmitt trigger circuit 18. Since this voltage is set so that it exceeds a threshold value of the Schmitt trigger circuit 18, an output of the Schmitt trigger circuit 18 changes from ''L'' to ''H'' level, a relay 20 is operable, a contact 20a is closed, a display lamp 6 is illuminated, allowing to quickly and easily confirm instruments to be monitored.