(三) 频率、计时电路 普教实验室中还有一类通用仪器是进行计时和测量频率的仪器。大规模集成电路的发展使目前已有可能设计数字式的单片频率计,使用单片集成电路,加几个元件,就可以构成一台能够测试频率、周期、频率比、时间间隔、单位计数等的通用频率测试仪。 (C) frequency, timing circuit General education lab there is a general type of instrument is to carry out timing and measuring the frequency of the instrument. The development of large scale integrated circuits makes it possible to design a digital monolithic frequency meter so far. Using a monolithic integrated circuit and adding a few components, it is possible to construct a test system capable of testing frequency, period, frequency ratio, time interval, unit count Such as the universal frequency tester.