在工业中,经常需要进行频率测量。例如测试振荡器的输出频率或是监视由变换器反映的机械振动频率。商业上有各种类型的频率表可用。但是在这里我们为那些希望建立自己实验手段的读者们介绍一个简单的线路。(该线路是由SGS—Fairchild发明的)。线路是由一个由晶体管Tr1和Tr2组成的放大器,及晶体管Tr3和Tr4组成的单稳多谐振荡器组成,如图所示。在工作时,待测信号馈给Tr1的基极,被 In industry, frequency measurement is often required. Such as testing the output frequency of the oscillator or monitoring the mechanical vibration frequency reflected by the converter. There are various types of frequency tables available commercially. But here we introduce a simple line for those who want to build their own experimental methods. (This line was invented by SGS-Fairchild). The line consists of an amplifier consisting of transistors Tr1 and Tr2 and a monostable multivibrator consisting of transistors Tr3 and Tr4, as shown. At work, the signal under test is fed to the base of Tr1