Circuit Diagram
How to Build It
- Place the NE555 timer on the breadboard.
- Connect pin 8 (VCC) to the positive rail and pin 1 (GND) to the negative rail.
- Connect pin 4 (RESET) directly to the positive rail (disabled).
- Connect a resistor from the positive rail to pin 7 (DISCHARGE) and to pin 6 (THRESHOLD).
- Connect an electrolytic capacitor from pin 6 to GND — the pulse length depends on this capacitor's and resistor's values.
- Connect pin 2 (TRIGGER) through a push button to GND (pressing it must pull pin 2 below 1/3 of the supply voltage).
- Connect pin 3 (OUTPUT) through a resistor to an LED, then to GND.
- Tap the button briefly — the LED should stay on for a fixed time, then turn off by itself, with no further button presses needed.
Bill of Materials
| Product | Code | Qty |
|---|---|---|
| Integrated circuit | — | 1 |
| Capacitor (electrolytic/ceramic/SMD/film) | 860020674015 | 1 |
| LED (3/5/10mm, SMD, power) | l-934ID-12V | 1 |
| Push button | 10100565(ALX-5A025) | 1 |
| Resistor | DR47K-8/9 | 1 |