Parts List
| Reference | Component | Notes |
|---|---|---|
| R1, R2, R3 | Resistor 10 kΩ | Three standard resistors |
| C1 | Capacitor 4.7 µF | Polarized capacitor |
| L1 to L10 | LED | Standard light-emitting diode |
| U1 | NE555 | 555 Timer IC |
| U2 | CD4017BE | 4017 Decade Counter |
Comments
The 555 timer circuit decides how fast the LEDs are “running”. Specifically R1, R2, and C1.
Since the 4017 chip only supports up to 2-3 mA of current out of its outputs, be sure to limit the current sufficiently with R3. 10 kΩ will limit the current to less than 1 mA.