Abstract: A regulator coupled to the main supply voltage generates a B+ scan voltage for a horizontal flyback transformer of a horizontal deflection circuit. A supply voltage is developed from a trace voltage in a flyback transformer secondary winding. The supply voltage is indicatiave of the horizontal deflection current amplitude. A decrease in mains supply voltage that cannot be compensated by the regulator, causes a corresponding decrease in the B+ scan and supply voltage and in a horizontal deflection current amplitude. The supply voltage is applied to the series arrangement of first and second resistors and a zener diode. A control voltage developed from the supply voltage, at a junction of the first and second resistors, is applied to a control terminal of a vertical deflection circuit for controlling the amplitude of the vertical deflection current. A decrease in the control voltage produces a greater proportional decrease in the vertical deflection current.