| 摘要 |
In a circuit for setting a chrominance signal controlling the emission of an electron beam in the picture tube of a color television receiver, the circuit including an amplifier connected to amplify the chrominance signal, with the output of the amplifier being held at a constant voltage level during each horizontal line blanking period by means of a keying pulse, and in which the amplifier is provided with a feedback path including an amplification determining resistance network, keying pulses are fed into the resistance network in such a manner that variation of the resistance presented by the network produces a simultaneous change in the gain of the amplifier and the direct voltage level of the chrominance signal at the output of the amplifier. |
