| 摘要 |
PURPOSE: A horizontal output transistor protective circuit is provided to protect a horizontal output transistor by constraining the increase in a collector voltage of the horizontal output transistor. CONSTITUTION: A microprocessor(20) detects the change of an input frequency and outputs a control signal according to a mode change. A signal transfer section(100) is switched according to the control signal from microprocessor(20). A synchronous processor(41) outputs a duty change signal to controlling a current flowing through a deflection coil of a horizontal output circuit according to a signal from signal transfer section(100). A horizontal size control circuit controls a voltage necessary to an operation of a horizontal output transistor(Q1) according to a duty of a pulse from synchronous processor(41). A horizontal drive circuit provides a driving voltage to a base of horizontal output transistor(Q1) according to a signal from synchronous processor(41). A horizontal output circuit receives an output of horizontal drive circuit and a voltage of horizontal size control circuit and provides an operation current to a horizontal deflection coil.
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