NE555+CD4017

As can be seen from the circuit diagram, the 3-pin output of NE555 is connected to pin 14 of CD4017, and pin 13 of CD4017 is connected to ground, indicating that the CD4017 triggers counting on the rising edge of the pulse. Regarding the function of pin 15, when pin 15 is at low level, the chip CD4017 will automatically reset and clear after counting ten times and count again. When pin 15 is at high level, it cannot be reset and cleared.

When turned on, pin 3 of the chip CD4017 will be in a high level state, while the other output terminals will be in a low level state, so only the LED light D2 will light up. Every time pin 14 inputs a rising edge, the high level output by the output terminal of CD4017 will move downward, from pin 3 to pin 2, then LED light D3 will light up, and the other lights will go out. After the 14-pin input clock pulse repeatedly, the 10 LED lights from D1 to D10 light up one by one, thus forming a flowing effect. Since the 15-pin of CD4017 is grounded, the automatic reset and clear function is realized. The ten LED lights from D1 to D10 are Each LED light will repeatedly create the effect of flowing water.