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电视信号发生器是电视维修中经常使用的一种仪器,它能产生一些特殊的电视信号供调整电视机时使用。本文介绍一种用 TTL 数字集成电路构成的简单电视视频信号发生器。本仪器能产生灰阶条、棋盘格、方格等三种电视信号。一般电视信号一帧由625行组成,分奇数场与偶数场,每场由312.5行组成。对于一般维修用电视信号,可采用逐行扫描,每帧由312行组成,本仪器就采用这种方式。图(1)是本仪器的电路原理图。主要以计数器为主体,通过对计数器的输出进行逻辑组
TV signal generator is often used in television repair instrument, it can produce some special TV signals used to adjust the TV. This article describes a TTL digital integrated circuit consisting of a simple TV video signal generator. The instrument can produce grayscale, checkerboard, squares and other three kinds of television signals. A general television signal consists of 625 lines, divided into odd field and even field, each field consists of 312.5 lines. For general maintenance of TV signals, can be progressive scan, each frame consists of 312 lines, the instrument on this approach. Figure (1) is the circuit diagram of the instrument. Mainly counter as the main body, through the output of the counter logic group