由于电力行业的特点，变电所安全运行钟不仅要求准确计时，而且要求在电网发生故障或掉电时能够锁定故障发生或掉电的时间．当故障消除或来电后，经过确认恢复到正常显示。为了达到这些要求，又使电路简单，系统运行可靠，我们采用了ATMEL公司的微处理器芯片89C51作为控制芯片 Due to the characteristics of the power industry, the safe operation of substation bell not only requires accurate timing, but also requires that the fault or power failure can be locked in the event of a power failure or power failure. When the fault is eliminated or calls, after confirmation to restore to normal display. In order to achieve these requirements, but also to make the circuit simple, reliable system operation, we use the ATMEL microprocessor chip 89C51 as a control chip