| 摘要 |
PURPOSE:To simplify and miniaturize a device for phase control by supplying a different criteria to one variable gain circuit synchronizing with an input signal of the color TV. CONSTITUTION:A synchronizing-signal separating circuit 9 separates a synchronizing signal from an input color TV signal (a). On the basis of this synchronizing signal, a pulse generating circuit 11 generates a driving pulse for a burst gate signal generating circuit 13. This circuit 13 generates and supplies a burst gate signal (b) to a changeover circuit 8. During the color burst signal period of the signal (a), the circuit 8 is connected to the side of a burst level circuit 7 by the signal (b) and a level criterion generated by the circuit 7 is supplied to the control input of the circuit 3 to adjust the level of the signal (b) automatically. In any period other than that of the signal (b), the circuit 8 is connected to the side of a video level circuit 6 and a level criterion generated by the circuit 6 is supplied to the control input of the circuit 3 to adjust the level of a video signal automatically. |
