| 摘要 |
PURPOSE:To cut off a PNP transistor when the shorting destruction occurs by changing the voltage supplied to a switching element and modulating and correcting by the frequency of the vertical deflection frequency simultaneously when the horizontal amplitude is changed. CONSTITUTION:When power is ON, a transistor 52 is biased through resistances 51 and 11 in the forward direction, and the current starts to flow. Then, since the collector current of the transistor 52 becomes the base current of a transistor 13, the transistor 13 starts to conduct is largely forward-biased. The voltage supplied to a switching element 3 is changed, the horizontal amplitude is changed, modulation is performed by the frequency of a vertical deflection frequency and the pin cushion distortion is corrected. Thus, when a transistor 3 and a damper diode 4 are shorting-destructed, they are grounded by the direct current resistance value of a choke coil 7, the collector current of the transistor 52 does not flow and the transistor 13 is cut off. |
