论文部分内容阅读
有线广播在农村宣传工作中占据非常重要的地位,但由于自然或人为的原因,广播线路常常中断,使有线广播不能很好地发挥其应有的作用。为此,笔者设计了一套实用的有线广播断线告知器,它在广播线路中断后,会立即发出声光告警信号,提醒广播工作人员及时查找断线部位,保证广播线路畅通。 工作原理 该装置由载波发射部分、载波接收及告警部分组成。图1为载波发射部分电路,安装于有线广播线路的终端。由IC1两个“非”门电路组成的高频振荡器产生振荡
Cable broadcasting occupies a very important position in rural publicity work. However, due to natural or man-made reasons, the broadcasting lines are often interrupted, so that cable broadcasting can not play its due role well. To this end, I designed a set of practical wired broadcast disconnection notifier, which interrupts the broadcast line, it will immediately sound and light alarm signals to remind radio staff to find broken parts in time to ensure smooth broadcasting lines. Working principle The device consists of a carrier transmitting part, a carrier receiving part and an alarm part. Figure 1 shows the carrier transmission part of the circuit, installed in the cable broadcast line terminal. High-frequency oscillator composed of two “NOT” gates of IC1 oscillates