| 摘要 |
PURPOSE:To improve the clamping capacity with a simple constitution, by connecting one end of a parallel circuit consisting of a resistance and a capacitor to the base of a transistor and grounding the other end and connecting the collector of the TR to a constant power source and applying a video signal to the emitter through the capacitor. CONSTITUTION:When the video input signal is inputted to an input terminal 8, the potential of a connection point 3 is lowered in the part of a vertical synchronizing signal. When the potential of the connection point 3 becomes lower than that of a connection point 2 by a certain value, a transistor (TR) 16 is operated. When the collector current of the TR16 is flowed from this connection point 2, the collector current of the TR16 is flowed from a terminal 5 with a magnitude several tens times as high as the base current. The sum of the base current and the collector current is flowed as the emitter current of the TR16 to the connection point 3 to charge a capacitor 9. Thus, the rise characteristic of the TR16 is improved, and an excellent clamping capacity is obtained. |
