Description

1.Principle:

Press S1, U1 NE555 integrated circuit 2, 4 pin will get low level at the same time; 555 output 3 pin is low level, 7 pin is discharging and 6 pin is low level. If loosen S1, 4 pin will become high level, then 2, 6 pin are both low level. Therefore, U1 NE555 output 3 pin is high level, Q2 is connected and the 4pcs LEDs on the left group will be on; at the same time, Q3 is connected, U2555 output low level, and the LEDs on the right group will be off.

2.Work Status:

the controller can control the on/off of the red lamp, green lamp and yellow lamp from four directions. When the red lamp on the east and west is on, the lamp on the south and north is on, and the cars and passers-by can go across the street; when the lamp on the east and west is transforming into green from red and the lamp on the south and north is transforming into red from green, the yellow lamp will flash

3.Parameter:

4.Component List:

NOTE:You can complete the installation by PCB silk screen and component listing.