Piezo disc (passive)
27 mm passive piezo disc · about 20 nF · makes no sound on DC: drive it with a tone (tone(), PWM or an oscillator) · loudest near its 4 kHz resonance · also works as a knock sensor
Try it on the benchThe lab drops it on an empty bench and opens its datasheet card.
Typical part: 27 mm passive piezo disc
Pins
- Red
- Black
Ratings and limits
| Capacitance | ≈ 20 nF |
|---|---|
| Resonance | ≈ 4 kHz |
| Drive | 3–30 V p-p |
How to use it
Unlike an active buzzer it has no oscillator: feed it a square wave (tone(pin, f) or a 555). It also works backwards as a knock or vibration sensor.