| 摘要 |
PURPOSE:To stabilize a high voltage with a few components without isolating a horizontal output circuit from a high voltage output circuit, by detecting the fluctuation of a beam current to change the capacitance of a capacitor of a resonance circuit of the horizontal primary system with this detected output. CONSTITUTION:A horizontal output transistor (TR)18 is driven with a horizontal output drive circuit 17 and a high voltage is applied to an anode 16 of a cathode-ray tube by a flyback transformer 6 and a high-voltage rectifier diode 9. When a beam current increases, the high voltage is dropped and a potential at point (b) split by resistors 14, 15 is dropped. When the potential at the point (b) is lowered, its change is outputted from an operational amplifier 10, the base potential of a resonance capacitance varying TR20 is lowered and the resonance capacitance comprising resonance capacitors 4, 19 is lowered. Thus, the voltage between secondary windings of the flyback transformer 8 is raised. When the beam current decreases, the reverse operation is performed. |
