| 摘要 |
PURPOSE:To reduce the power consumption of a horizontal output stage by changing a power voltage of the said horizontal output stage so as to control the horizontal amplitude and changing interlockingly the power voltage of the horizontal drive stage in a horizontal deflection circuit suitable for a monitor or a video projection with high resolution. CONSTITUTION:In changing a horizontal amplitude of a video picture, a slider 14a of a variable resistor 14 to adjusted to change the voltage obtained at the emitter of a transistor (TR) 12 thereby changing the horizontal amplitude of the video picture. In changing the horizontal amplitude on the video picture since the power voltage of a horizontal drive transformer 3 is changed similarly, a base current iB of a TR 6 is changed proportional to a collector current iC of the TR 6 and when the video pattern is small, the base current iB is changed into a current iB0, and when the video pattern is large, the base current iB is changed into a current iB1. Thus, even when the size of the video pattern is changed, the power loss due to the base current iB of the TR 6 is minimized always. |
