Piezoelectric Sensor /Buzzer/Transducer 27mm
Piezoelectric Sensor /Buzzer/Transducer 27mm
Piezoelectric Sensor /Buzzer/Transducer 27mm
Piezoelectric Sensor /Buzzer/Transducer 27mm
Piezoelectric Sensor /Buzzer/Transducer 27mm
Piezoelectric Sensor /Buzzer/Transducer 27mm

Piezoelectric Sensor / Buzzer / Transducer 27mm

Sensors
BUZ001
€2.00
In Stock
Immediate Dispatch
Piezoelectric Sensor / Buzzer / Transducer 27mm — a dual-purpose piezo disc that detects vibration, knock, or tap inputs and acts as a compact audio transducer. Outer disc 27mm, ceramic disc 21mm, thickness ~0.45mm. Ideal for Arduino knock sensors and buzzer circuits.

Quantity Price
10+ €1.50
50+ €1.00
 

The Piezoelectric Sensor / Buzzer / Transducer 27mm (SKU: BUZ001) is a versatile piezo disc element that works in two directions: it generates a voltage when mechanically stressed (sensor mode) and produces sound when driven by an electrical signal (buzzer/transducer mode). This dual nature makes it one of the most cost-effective components in any maker's toolkit.

Key Features

  • Dual functionality: Works as a vibration/knock sensor AND as an audio transducer — two components in one
  • Outer Disc Diameter ~27mm: Large enough for reliable vibration pickup — easy to mount on surfaces or enclosures
  • Ceramic Disc Diameter ~21mm: The active piezo ceramic area determines sensitivity — good signal output for knock detection
  • Ultra-thin profile ~0.45mm: Extremely low-profile design — fits into tight spaces and thin enclosures
  • Passive piezoelectric type: Requires an external oscillator signal to produce sound — gives full frequency control from your microcontroller
  • No polarity restriction in sensor mode: Outputs an analog voltage proportional to impact force — simple to read with any analog input pin

Typical Applications

  • Knock / tap sensor: Attach the disc to a surface and read the analog voltage spike on your Arduino or ESP32 — ideal for knock-activated switches, drum triggers, or interactive surfaces
  • Vibration detector: Mount on machinery or enclosures to detect mechanical vibration and trigger alerts
  • Compact buzzer: Drive with a PWM signal from a microcontroller to produce tones, beeps, or simple melodies
  • Musical / audio projects: Use as a contact microphone or piezo speaker element in DIY synthesizers and noise instruments
  • Security / alarm systems: Embed in doors or windows to detect glass-break or physical impact events

Compatibility

  • Arduino UNO / Nano / Mega: Connect directly to any analog input pin (A0–A5) for sensor mode, or to a digital PWM pin (with a current-limiting resistor) for buzzer mode — 5V system compatible
  • ESP32 / ESP8266: Use with a voltage divider or series resistor to protect the 3.3V ADC input when used as a sensor
  • Raspberry Pi: Use in sensor mode via an external ADC (e.g. MCP3008) since Raspberry Pi has no native analog input
  • Any microcontroller: Passive element — works with any platform that can read analog voltage or output a PWM signal

Technical Specifications

ParameterValue
TypePiezoelectric (passive)
Outer Disc Diameter~27mm
Ceramic Disc Diameter~21mm
Thickness~0.45mm
SKUBUZ001

FAQ

Q: What is the difference between a passive piezo transducer and an active buzzer?
A: A passive piezo transducer (like this one) requires an external oscillating signal — typically a PWM output from a microcontroller — to produce sound, giving you full control over frequency and tone. An active buzzer has a built-in oscillator and beeps at a fixed frequency when power is applied.

Q: Do I need a resistor when connecting this as a knock sensor to Arduino?
A: Yes — it is recommended to add a 1MΩ resistor between the two leads to discharge the piezo element slowly and prevent voltage spikes from damaging the ADC input pin of your microcontroller.

Package Contents: 1 × Piezoelectric Disc Transducer 27mm (leads pre-attached)

⚠ Note: This is a passive piezo element. It does not include a driver circuit or oscillator. When used as a knock sensor, add a 1MΩ bleed resistor across the leads to protect your microcontroller's analog input from voltage spikes.
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