10-LED chaser: 555 + CD4017
Open in the lab ▸Make my own copy
The classic “running light”. A 555 timer ticks about six times a second, and a CD4017 decade counter moves one step on every tick, lighting its ten outputs one after another. Only one LED is on at a time, so all ten share one 470 Ω resistor. Try it: change C1 to 1 µF and the light runs twice as fast; change it to 10 µF and it crawls. Add a pot in series with R2 to make a speed knob.
What is on the bench
39 parts, 59 wires.
| LED | 10 |
|---|---|
| Resistor | 3 |
| 9 V battery | 1 |
| 555 timer | 1 |
| Electrolytic capacitor | 1 |
| Ceramic capacitor | 1 |
| CD4017 decade counter | 1 |
Put it on your page
The project runs live inside the frame: readers can press buttons, turn knobs and read the meters.
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Link
https://zencircuitlab.com/p/zclchaser10
Published by its author under the lab's community terms: it may be opened, copied and changed by anyone. Simulation results are for learning; check a real build against the parts' datasheets.