How Much do You Know about the Working Principle of Cars Traffic Lights

I believe that many people know what the cars traffic light is, and also know how it looks like, but few people know how it work. Today, I will simply share the working principle of cars traffic light with you:


(1) The timer

The timer consists of a counter that synchronizes with the system’s second pulse (provided by the clock pulse generator). It requires the counter to be cleared at first under the action of the status signal ST, and then under the action of the rising edge of the clock pulse, the counter begins to work by adding by 1 count from zero every time, providing the controller with the timing signal TY of mode 5 and TL of mode 25.


(2) The controller

The controller is the core of traffic management, and it should be able to control the transition of signal lights' working condition according to traffic management rules. Two D flip-flops FF1 and FFO are selected as the timing register to generate 4 conditions. The prerequisites for the controller condition transition are TL and TY. When the controller is in the condition of Q1n+1Q0n+1= 00, if TL= 0, the controller stays in the condition of 00; If TL=, then the controller will switch to the condition of Q1n+1Q0n+1= 01. These two cases are independent of the condition TY, so that it is denoted by the independent term "X", and so on.


(3) The decoder

The main task of the decoder is to translate the four working conditions of the output Q1 and Q0 of the controller into the working conditions of the 6 signal lights on the lane A and lane B.


This is how cars traffic lights work. If you have any questions, please contact Sinowatcher. We will be happy to serve you.

Related Product