夜间行车,若开远光灯会车常常影响行车安全。为此设计一种电路图,以实现会车时自动变换灯光。 下图为远近灯光自动变换原理图,图中K表示开关,电阻R是用来控制会车时,从CdS流过继电器J的最大电流。CdS是硫化镉光敏电阻,有光线照射时阻值变小,反之变大。J表示双极继电器,触点1和2是固定的触点,3是活动触点,触点1和3常闭合。闭 Driving at night, if the high light cars will often affect traffic safety. To this end, the design of a circuit diagram, in order to achieve when the car will automatically change the light. The following picture shows the principle of automatic conversion of the near and far light. In the figure, K denotes the switch. The resistance R is used to control the maximum current flowing from the CdS through the relay J when it meets a car. CdS is a cadmium sulfide photoresistor, the resistance of light irradiation becomes smaller, on the contrary, larger. J indicates a bipolar relay, contacts 1 and 2 are fixed contacts, 3 is a movable contact and contacts 1 and 3 are normally closed. close