| 摘要 |
PURPOSE: A supply power varying circuit of a horizontal output part is provided, which varies a power supply voltage applied to a horizontal driving transformer according to each inputted horizontal frequency. CONSTITUTION: A horizontal synchronous signal is applied to a base of a switching transistor(Q1) from a horizontal drive circuit. When a low level signal is inputted, the switching transistor is turned off. Therefore a B+ voltage is applied to a primary part(T1) of a horizontal driving transformer(T) through a resistor(R1), and at the same time is applied to a capacitor(C4) through a diode(D2) and thus the capacitor is charged. Also, a power supply voltage is induced to a secondary part(T2) of the horizontal driving transformer, and a horizontal output transistor(Q2) is driven. If a high level signal is inputted to a base of the switching transistor, the switching transistor is turned on and thus a power is not applied to the primary part of the horizontal transformer and thus charges in the capacitor are inverted and thus flowed to B+ through a diode(D3) and a resistor(R2). Finally, a voltage(Vcc) applied to the primary part of the horizontal driving transformer is controlled by the B+ voltage.
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