| 摘要 |
PURPOSE:To correspond to the horizontal frequency of a wide range by connecting a drain becoming the minus power source of FET in a power modulation circuit for horizontal deflection output to a DC power source which is dropped to 1/2 to 1/4 of a main power source for horizontal deflection without dropping it to ground. CONSTITUTION:The secondary-side rectification voltage V1 of a switching transformer T1 is supplied to the drain of N-channel type FETQ2 as the main power source for horizontal deflection. The DC power source V5 dropped to 1/2 to 1/4 of the main power source for horizontal deflection V1 is supplied to the drain of P-channel type FTQ3. A sawtooth wave and a parabolic wave, which are vertically synchronized, are usually used for a correction wave for horizontal deflection modulation V3, and a waveform obtained by modulating V1 by V3 is obtained. Horizontal deflection power modulation output V2 is obtained from the sources of FETQ2 and Q3, and it is feed back-controlled by an operand amplifier IC1 so that it becomes equal to V4. Thus, the voltage of V2-V5 is applied across the source and the drain of P-channel FETQ3. |
