1. Mainly consisting of clock generation circuit and decimal counter circuit.
2. The self-excited multivibrator with NE555 as the core, the power supply charges the capacitor C1 via R2, R3, R4. When C1 starts charging, NE555s 2-pin is still at low level, so the output pin 3 is at high level. When the power supply via R2, R3 and R4 is charged to the 2/3 power supply voltage, the level of the output pin 3 changes from high to low, and the internal discharge tube of the NE555 is switched on. The C1 capacitor is discharged via the 7-pin of R4, R3 and NE555. Until the voltage at C1 is less than 1/3 of the supply voltage, the level of the NE555 3-pin changes from low level to high level. C1 is recharged and the cycle forms a vibration.
3. The charging time is:0.695(R2+R3+R4) C1, the discharge time is:0.695(R4+R3) C1, R4 can be adjusted to control the output frequency of the oscillator, and the clock oscillation signal of NE555 is continuous to 14. is continuous . Pin added by CD4017.
4. Ten LEDs are connected to the 10 outputs of the CD4017. When the 10 outputs of the CD4017 alternately produce a high level under the action of the clock signal, D1--D10 are illuminated one by one another to create a water light effect.
5. Adjust the R4 to adjust the flow speed of the LED light.

Specification:
Item type: water flowing light
Voltage: 2.5~14.5V
Size: 5.4 x 2.1 cm / 2.13 x 0.83 inches.
Thickness: 1.6 mm.

Box contents:
2 x module.