Build an NE555 LED Flasher Circuit
Beginner
Est. Time: 30 minutes
Est. Total: $12.38
The classic first electronics project. Build an astable multivibrator using the NE555 timer IC to flash an LED at an adjustable rate. No microcontroller needed — just pure analog electronics. Perfect for understanding how timing circuits work and a great intro to breadboard prototyping.
Bill of Materials — Available in Our Shop
| Part | Qty | Price | Total | Status |
|---|---|---|---|---|
| NE555 Timer IC (DIP-8) Timer IC — generates the oscillating signal |
1 | $0.99 | $0.99 | In Stock |
| 830-Point Breadboard + Jumper Wires + Power Supply Kit Prototyping platform with power supply and jumper wires |
1 | $7.99 | $7.99 | In Stock |
| Subtotal (from our shop) | $8.98 | |||
Additional Parts Needed
These common parts are available at most electronics retailers. Estimated prices shown for budgeting.
| Part | Qty | Est. | Total |
|---|---|---|---|
| 5mm LED (any color) | 1 | $0.10 | $0.10 |
| 220 ohm Resistor | 1 | $0.05 | $0.05 |
| 10K ohm Resistor | 1 | $0.05 | $0.05 |
| 47K ohm Resistor | 1 | $0.05 | $0.05 |
| 10uF Electrolytic Capacitor | 1 | $0.10 | $0.10 |
| 0.01uF Ceramic Capacitor | 1 | $0.05 | $0.05 |
| 9V Battery + Snap Connector | 1 | $3.00 | $3.00 |
| Est. external subtotal | $3.40 | ||
Parts from our shop$8.98
Est. external parts$3.40
Est. Project Total$12.38
Step-by-Step Instructions
- Place the NE555 IC on the breadboard, straddling the center channel. Pin 1 goes to the ground rail, pin 8 to the positive rail.
- Connect the 10K resistor between pin 7 (Discharge) and the positive rail. Connect the 47K resistor between pin 7 and pin 6 (Threshold).
- Connect the 10uF capacitor between pin 6 and ground. This capacitor controls the flash rate — larger values flash slower.
- Bridge pin 6 to pin 2 (Trigger) with a short jumper wire. Place the 0.01uF capacitor between pin 5 (Control Voltage) and ground.
- Connect the 220 ohm resistor from pin 3 (Output) to the LED anode. Connect the LED cathode to ground.
- Connect the 9V battery snap to the power rails (or use the included power supply module via USB). The LED should begin flashing immediately at roughly 1 Hz. Swap resistor values to adjust the rate.