LED Blinker (555 Timer)

Circuit Diagram

How to Build It

1. Place the NE555 timer chip on the breadboard, pin 1 at the bottom-left.
2. Connect pin 1 (GND) to the negative rail and pin 8 (VCC) to the positive rail (9V).
3. Connect a 10K resistor between VCC and pin 7 (DISCHARGE).
4. Connect a second 10K resistor between pin 7 and pin 6 (THRESHOLD).
5. Connect a 100uF electrolytic capacitor between pin 6 and GND — this sets the blink speed.
6. Connect pin 2 (TRIGGER) directly to pin 6.
7. Connect pin 4 (RESET) directly to VCC.
8. Connect the LED (with its current-limiting resistor in series) between pin 3 (OUTPUT) and GND.
9. Power the circuit — the LED should blink roughly once per second.

Bill of Materials