| 摘要 |
PURPOSE:To absorb effectively a surge pulse produced by the discharge in a CRT by interposing a constant voltage diode between the interstage coupling line of a video amplifying circuit or color signal amplifying circuit and a DC potential source. CONSTITUTION:Zener diodes 8R, 8G, and 8G are interposed between the ground and interstage coupling lines 3R, 3G, and 3B which perform DC coupling between the primary color driving stage of a chroma IC1 incorporating a band amplifying circuit, demodulating circuit, etc., and the primary color output amplification stage consisting of transistors (TR) 5R, 5G, and 5B. Even when large surge pulses are induced on the interstage coupling lines 3R, 3G, and 3B owing to the discharging in the CRT, they are clipped by the Zener diodes 8R, 8G, and 8B to an operating voltage level, so the chroma IC1 and the TRs 5R, 5G, and 5B for color output amplification are prevented from being supplied with an excessive pulse and thus protected. |
