The WaterLight LED module uses an NE555 timer and a CD4017 counter to drive ten LEDs in a smooth water‑like running pattern - What it is A compact standalone LED driver that creates a dynamic chase effect using ten LEDs connected to the CD4017 outputs - How it works An RC network around the NE555 sets the clock that feeds the CD4017. The counter advances on each pulse and lights LEDs D1–D10 in sequence, producing a water light effect - Speed control Adjust the resistor R4 to change the clock frequency and thus the speed of the LED flow - Outputs and wiring Ten LEDs are connected to the ten CD4017 outputs. As clock pulses arrive, the LEDs illuminate one after another for a continuous running effect - Compatibility and build Operates from common DC supply ranges (typical 5 to 12 V). Built on a compact PCB with standard components for easy integration into projects - Benefits No microcontroller required for the effect, simple RC timing, reliable operation, low component count, easy to power and fit into small enclosures - Use cases decorative lighting for home, bars, or aquarium backdrops; educational electronics project to learn RC timing and counter operation; stage props or signage needing a subtle moving light effect