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本文以测试汽油机的油耗时间为例,介绍一个简单实用的开关信号时间显示电路,见图1。它由三块CL102型十进计数显示器、RC环形振荡器和开关信号逻辑门,加上光开关信号放大电路组成。其工作原理简述如下: 当油泡中的油面下降到位置A时,光敏管G_1受光照,为BG_1提供基极电流。从而使BG_1导用,使F_1输出为逻辑1(高电平)。这时因BG_2截止,使F_3输出为逻辑1。由图可知,F_1输出的高电平,一方面利用其上升沿去触发由双D触发器组成的清零脉冲发生器,发出一个CL102计数显示器的清零信号;另一方面去打开与非门YF,让RC环形振荡器产生的0.1秒脉冲
In this paper, the test gasoline engine fuel consumption time, for example, introduces a simple and practical switch signal time display circuit, shown in Figure 1. It consists of three CL102 decimal counter display, RC ring oscillator and switching signal logic gate, coupled with the optical switch signal amplifier circuit. The working principle is briefly described as follows: When the oil surface of the oil bubble drops to the position A, the light-sensitive tube G_1 is illuminated to provide the base current for BG_1. Thus making BG_1 lead, so that F_1 output logic 1 (high). At this moment BG_2 ends, making F_3 output logic 1. As can be seen from the figure, F_1 output high level, on the one hand to use its rising edge to trigger the double-D flip-flop composed of reset pulse generator, issued a CL102 counter display clear signal; on the other hand to open the NAND gate YF, a 0.1 second pulse for the RC ring oscillator