公开(公告)号：US3692933A

公开(公告)日：1972-09-19

申请号：US3692933D

申请日：1970-10-28

Applicant: ADMIRAL CORP

Inventor： KNOLL RONALD S

IPC: H03G3/26 ,  H04N3/20 ,  H04N5/68

CPC classification number: H03G3/26 ,  H04N3/20

Abstract: A protective circuit is disclosed which is adapted to detect and indicate an overvoltage condition in a television receiver by blanking both sound and picture information. The circuit is coupled between an output of the receiver''s high voltage transformer and an input of the receiver''s automatic gain control (AGC) system. The normal input signal to the AGC circuit is a video information component of a broadcast television signal selected by the tuner and amplified. The AGC system normally responds to the varying signal strength of the synchronizing signal information of the video signal to control the gain of the receiver''s tuner and IF amplifier sections. Should the output of the receiver''s high voltage transformer rise above a predetermined level, the protective circuit generates a failure signal which causes the AGC system to cut off signal flow through the tuner and IF sections, thus terminating both audio and video reproduction by the receiver.

Abstract translation: 公开了一种保护电路，其适于通过消隐声音和图像信息来检测和指示电视接收机中的过电压状况。 电路耦合在接收机的高压变压器的输出端和接收机的自动增益控制（AGC）系统的输入端之间。 AGC电路的正常输入信号是由调谐器选择并广播的广播电视信号的视频信息分量。 AGC系统通常响应视频信号的同步信号信息的变化信号强度来控制接收机的调谐器和IF放大器部分的增益。 如果接收机的高压变压器的输出高于预定电平，则保护电路产生故障信号，使得AGC系统切断通过调谐器和IF部分的信号流，从而终止接收机的音频和视频再现。