| 摘要 |
PURPOSE:To establish the vertical deflection circuit in low power consumption, by turning on and off the pump up power supply and scanning power supply alternately during scanning and blanking period. CONSTITUTION:The output of the vertical oscillation circuit 11 is fed to the vertical deflection coil 14 via the saw tooth wave generation circuit 12, and vertical amplifying output circuit 13. The comparator 17 compares the output voltage of the output circuit 13 with the scanning power supply Vcc, and when the voltage at the input terminlas A, B is B>=A, an output is made. The logical sum circuit 22 receives the output of the oscillation circuit 11 and comparator 17 to control the switch circuit 21. As a result, during the scanning period, the switch 21 is opened and the scanning power supply Vcc is given to the output circuit 13 via the diode 19. During blanking period, the switch 21 is closed and the pump up power supply, Vcc<Vr, is given to the output circuit 13. In this case, the diode 19 is made to cut-off state. |
