此十字路口交通灯控制系统，分东西道和南北道，设东西道为A道，南北道为B道。规定：首先，东西路口红灯亮，南北路口绿灯亮，同时开始25s倒计时，以7段数码管显示时间。25s倒计时结束后开始5s倒计时，南北路口的绿灯闪烁，计时到最后2s时，南北路口黄灯亮。完成1次这样的循环需要30s。30s结束后，南北路口红灯亮，东西路口绿灯亮，并重新30s倒计时，依次循环。若有紧急车辆要求通过时，此系统应能禁止普通车辆，而让紧急车辆通过。

-This control system for traffic lights at a crossroads, and North-South Road at East-West Road, located east-west Road for A Road, B Road, North-South Road. Requirements: First of all, what the red light at the junction, north-south road junctions green, at the same time the beginning of 25s countdown to 7 digital tube display time. 25s countdown 5s after the end of the beginning of the countdown, the green light flashes at the junction of the North and the South, a time to the last 2s, the north-south road junctions yellow light. Complete 1st cycle of the need for such 30s. 30s after the end of the red light at the junction north-south, east-west road junctions green and re-30s countdown, followed by the cycle. If so called for the adoption of emergency vehicles, this system should be able to prohibit ordinary vehicles, and let emergency vehicles through.