PURPOSE: To reduce circuit scale by using a chopper power source while sharing it for deflection and high voltage by providing a high voltage stabilizing circuit and preventing the output voltage of the chopper power source from being changed even when the high voltage regulation of a high voltage output circuit is fluctuated.

CONSTITUTION: A B voltage control circuit 7 is constituted for detecting the output fluctuation of a horizontal deflecting output circuit 6. When a divided voltage is lowered, a feedback amount is changed so as to reduce this output and inputted to a chopper power source 2. At this chopper power source 2, the output of the DC output circuit 6 is kept at a fixed level corresponding to this input. Therefore, the DC output voltage of the chopper power source 2 can be prevented from being changed by the fluctuation of the high voltage regulation of a high voltage output circuit 4 by using a high voltage stabilizing circuit 3, and the chopper power source 2 can be used both for deflection and high voltage.