| 摘要 |
A synchronizing signal amplifier which has an input terminal coupled to a source of synchronizing signals and noise signals by means of a capacitor has its common terminal coupled to reference potential by means of a switching circuit having its input terminal coupled to the source of synchronizing signals and noise signals. When signals produced by the source of synchronizing signals and noise signals are less than a noise threshold level established by the switching means, the common terminal of the amplifier is coupled to reference potential by the switching means and the current through the capacitor is basically a function of the input impedance of the amplifier. |
