Piezoelectric Sensor/Transducer/Buzzer - 26mm Diameter

26mm Piezoelectric Transducer (Buzzer & Knock Sensor)

This 26mm Piezoelectric Transducer is an incredibly versatile and low-cost component for any electronics project. A "transducer" is a device that converts one form of energy into another. This piezo element excels at two functions: it converts electrical energy into mechanical energy (creating sound) and mechanical energy into electrical energy (sensing vibration). This dual-use capability makes it an essential part for adding audio feedback or sensing user interaction.

🔧 Key Features

• Dual Functionality: Use it as a buzzer to create beeps, tones, and alarms, or as a sensor to detect knocks, taps, and vibrations.
• Sound Output (Buzzer): When driven with an oscillating signal (like a PWM or `tone()` function from an Arduino), the element vibrates to produce a clear, high-pitched sound.
• Sensor Input (Knock Sensor): When the ceramic disc is tapped, flexed, or exposed to vibration, it generates a small analog voltage. This "piezoelectric effect" is perfect for creating a knock sensor or a simple vibration detector.
• Standard 26mm Size: A common diameter that provides a good balance between sound output and sensing sensitivity.
• Solid-State & Thin: No moving coils or magnets. Its extremely thin profile allows it to be mounted discreetly on surfaces.
• Easy to Interface: A simple two-wire connection (positive and ground) makes it incredibly easy to connect to any microcontroller.

💡 Applications

• Audio Feedback: Add confirmation beeps to buttons, create alarm sounds, or build simple musical toys.
• Knock & Tap Sensors: Create a "knock-to-unlock" secret lock, a tap-activated switch, or a drum pad for a DIY electronic drum kit.
• Vibration Detection: Use it as a simple sensor to detect if a machine is running or if an object has been moved.
• Contact Microphone: Can be used to amplify and record surface vibrations, like a DIY stethoscope.

⚙️ Technical Specifications

📦 Package Includes

• 1 × 26mm Piezoelectric Transducer with Wires

✅ Why Choose This Component?

• Two Components in One: Why buy a separate buzzer and knock sensor? This versatile disc does both jobs perfectly.
• Incredibly Simple to Use: Drive it with a `tone()` command or read it with an `analogRead()` (often with a parallel resistor).
• Low Cost, High Utility: An extremely affordable way to make your projects interactive and responsive.
• Flat Profile: Its thin, disc-like shape makes it easy to glue or tape onto any flat surface for sensing or sound.

Note: As a buzzer, this is an "external drive" type. It will not make a sound if you connect it to a steady DC voltage. It must be driven with an AC or oscillating signal (like from a PWM pin) to produce a tone.