CIRCUIT ARRANGEMENT FOR STABILIZING THE ELECTRON BEAM FOCUSING THEREOF FOR AN ELECTROMAGNETIC FOCUSING TYPE CAMERA TUBE

摘要

CIRCUIT ARRANGEMENT FOR STABILIZING THE ELECTRON BEAM FOCUSING THEREOF FOR AN ELECTROMAGNETIC FOCUSING TYPE CAMERA TUBE A circuit arrangement for stabilizing the electron beam focusing thereof is used for an electromagnetic focusing type camera tube having a high voltage generating circuit for supplying voltage for operation to electrodes of the camera tube, a focusing current supplying circuit for supplying current of focusing to an electron beam focusing coil of the camera tube, and a voltage source for applying voltage for operation to said high voltage generating circuit and said focusing current supplying circuit. The focusing current supplying circuit comprises an operational amplifier having an output terminal to which the focusing coil is connected, a resistor for detection connected at one end thereof to the focusing coil and an inverting input terminal of the operational amplifier and at the other end thereof to ground, a first resistor connected between said voltage source for applying voltage for operation and a non-inverting input terminal of said operational amplifier, a reference voltage source, and a second resistor connected between the reference voltage source and the noninverting input terminal of the operational amplifier.