12V Active Piezoelectric Buzzer – Small PCB Mount Self-Driven Buzzer with Built-in Oscillator

12V Active Piezoelectric Buzzer – Small PCB Mount with Built-in Oscillator

The 12V Active Piezoelectric Buzzer (CMP-QC2898) is a compact, self-contained sound-generating component with a built-in oscillator circuit. Unlike passive buzzers that require an external PWM signal to produce sound, this active buzzer produces a continuous fixed-frequency tone (~2.5 kHz) simply by applying a 12V DC supply across its terminals — making it the simplest possible solution for audio alert, alarm, and notification applications in electronic circuits.

Its PCB through-hole / panel mount form factor, low power consumption, compact size, and wide operating temperature range make it suitable for integration into alarm systems, timers, home automation controllers, industrial indicators, and embedded electronics projects.

Key Features

• Active Buzzer: Built-in oscillator — produces sound directly from DC voltage, no PWM needed
• Operating Voltage: 12V DC
• Fixed Frequency Output: ~2.5 kHz — consistent audible tone every time
• Low Power Consumption: Long operating life with minimal current draw
• PCB Through-Hole Mount: Easy soldering and secure board integration
• Compact & Lightweight: Minimal footprint for space-constrained PCB designs
• Wide Temperature Range: -20°C to +60°C — suitable for indoor and light industrial environments
• Polarity Sensitive: Observe correct polarity (+ and −) when connecting

Technical Specifications

Active vs Passive Buzzer – Key Difference

How to Use with Arduino (via NPN Transistor BC547)

Since the buzzer operates at 12V DC, it cannot be driven directly from a 5V Arduino GPIO pin. Use an NPN transistor (e.g. BC547 or 2N2222) as a switch:

// Arduino GPIO → 1kΩ resistor → BC547 Base
// BC547 Collector → Buzzer (−)
// Buzzer (+) → 12V supply
// BC547 Emitter → GND (shared with Arduino GND)

#define BUZZER_PIN 8

void setup() {
  pinMode(BUZZER_PIN, OUTPUT);
}

void loop() {
  digitalWrite(BUZZER_PIN, HIGH);  // Buzzer ON
  delay(1000);
  digitalWrite(BUZZER_PIN, LOW);   // Buzzer OFF
  delay(1000);
}

Compatible Platforms

• Standalone 12V DC circuits (direct connection)
• Arduino Uno, Nano, Mega (via NPN transistor or relay)
• ESP32, ESP8266 (via NPN transistor or MOSFET — 3.3V GPIO)
• Raspberry Pi (via transistor switching circuit)
• 12V relay-controlled alarm and timer circuits
• Industrial PLCs and control panels (12V logic systems)

Applications

• Alarm Systems: Burglar alarms, fire alarms, door/window open alerts
• Timers & Counters: End-of-cycle beep indicators
• Home Automation: Motion detection alerts, doorbell circuits
• Industrial Indicators: Process complete / fault notification buzzers
• Electronic Toys: Sound effects and game alert circuits
• Embedded Systems: Boot-up confirmation beep, error alert
• Educational Projects: Arduino alarm labs, STEM kits

Important Usage Notes

• Do NOT connect directly to Arduino 5V GPIO — this buzzer requires 12V DC to operate correctly.
• Polarity sensitive — always connect positive (+) terminal to 12V and negative (−) to GND/transistor collector.
• Use a BC547, 2N2222, or IRF540N MOSFET as a switch when controlling from a 5V or 3.3V microcontroller GPIO.
• Add a 1N4007 flyback diode in parallel (cathode to +12V) for back-EMF protection in sensitive circuits.
• This is an active buzzer — it produces a fixed tone only; it cannot play melodies or variable frequencies.

Package Contents

• 1 × Small 12V Active Piezoelectric Buzzer (PCB Through-Hole)

Tip: For variable tone / melody generation, consider the 5V Passive Buzzer paired with Arduino's tone() function instead.