27mm Piezoelectric Ceramic Disc Sensor – Vibration & Knock Sensor for Arduino & DIY Instruments

Overview 

The 27mm Piezoelectric Sensor (also known as a transducer or pickup) is a versatile component that works as both a sensor and a sounder. When the ceramic element is bent or hit, it generates a small electrical charge, making it ideal for detecting impacts. Conversely, if you apply an oscillating signal to it, it will vibrate and act as a thin, high-pitched buzzer. At 27mm, it offers a great balance between sensitivity and surface area, making it the most popular choice for makers building instrument pickups or touch-sensitive surfaces.

Key Features 

• Dual-Functionality: Use it as a vibration/knock sensor (input) or as a basic buzzer/beeper (output).

• High Sensitivity: Capable of detecting even slight taps or nearby vibrations.

• Ultra-Thin Profile: Easily mounts under surfaces, inside guitar bodies, or on top of drum pads without adding bulk.

• Easy Interface: Simple two-wire connection (Positive and Ground).

• Robust & Reliable: No moving parts to wear out, providing a long lifespan for industrial or hobbyist projects.

Technical Specifications 

Feature	Specification
Diameter	27mm
Material	Brass (Plate) + Ceramic (White Element)
Resonant Frequency	$4.0 \pm 0.5 \text{ kHz}$
Resonant Impedance	$200 \Omega$ (Max)
Static Capacitance	$25.0 \text{ nF} \pm 30\%$
Operating Temp	-20°C to +70°C
Thickness	Approx. 0.5mm