【摘要】 在一些自动控制系统中，微机要检测某条支路是 否加有交流２２０ Ｖ 的电压。针对这种情况，本文提出了一种方法，采用电阻、电容器件等，构成一条回路，只要选择合理的参数，就能产生一个代表线路情况的逻辑量。微机通过检测这个逻辑量的数 值， 来测知该支路的情况。此外，本文就参 数的选择方法及多路时的测量情况，也做出了详细的论述。更多还原

【Abstract】 A branch circult, whether AC 220 V voltage is applled to, needs to be detected by a microprocessor in some control systems. A method is proposed in this paper, using resistors and capacitors etc to construct a circult for the purpose. Logic quantity representing the circult situation can be resulted from the selection of reasonable parameters. The values of the logic quantity are detected by the microprocessor in order to monitor the state of the branch circult. The selection manner of parameters and the measurement conditions at multi-circuit are also discussed here in detalls.更多还原