交通灯控制系统，东西向绿灯亮若干秒，黄灯闪烁几次后红灯亮，红灯亮后，南北向由红灯变为绿灯，若干秒后南北向黄灯闪烁几次后变红灯，东西向变绿灯，如此重复-Traffic light control system, something the green light for several seconds, the yellow light flashes a few times after the red light after red light, red light into green light from the north to south, the north and south to the yellow light flashes several times changed several seconds after the red light something to change the green, so repeat