Circuit Diagram
How to Build It
- Connect the electret microphone's + terminal to +9V through a 4.7K resistor, and the - terminal to ground.
- Connect a coupling capacitor (100nF or similar) from the microphone's output to the transistor's base.
- Connect a 10K bias resistor from the transistor's base to +9V.
- Connect the transistor's emitter to ground.
- Connect the LED (with current-limiting resistor) between the transistor's collector and +9V.
- Clap near the microphone — the LED should flash briefly on each loud sound.
Bill of Materials
| Product | Code | Qty |
|---|---|---|
| LED (3/5/10mm, SMD, power) | OSR5PA5111A | 1 |
| Microphone | 04 148 | 1 |
| Resistor | DR100R-418 | 1 |
| Resistor | #N/A | 2 |
| Transistor (incl. IGBT) | — | 1 |