12mm Passive Buzzer with 5V Operating Voltage

A passive buzzer is a type of sound-emitting device that lacks an in-built oscillating circuit. This means it relies on an external signal to generate sound. This signal could be an AC (alternating current) or a PWM (pulse-width modulation) signal from a microcontroller or another external circuit.

Key Features

• No Built-in Oscillator: Unlike active buzzers, passive buzzers require an external oscillating signal to generate sound.
• Operating Voltage: They typically operate at low DC voltages, usually between 3V and 12V.
• Versatile Sound Generation: Capable of generating a wide range of frequencies and tones based on the input signal.
• Flexible Control: The input signal can be modulated to generate various sounds, melodies, and frequencies.

Technical Specifications

• Dimensions: Available in various sizes, often similar to active buzzers, such as 12mm or 9mm in diameter.
• Sound Level: Typically produces sound levels between 70 to 85 dB, but this can vary based on the input signal.
• Frequency Range: Can generate a wide range of frequencies, typically between 1kHz and 5kHz, depending on the input.
• Current Consumption: Usually low, around 10-30 mA, but can vary based on the input signal characteristics.

Applications

• Electronic Projects: Commonly used in Arduino and other microcontroller projects for specific tones or melodies.
• Alarm Systems: Used in security and alarm systems to generate various alert sounds.
• Home Appliances: Employed in appliances like washing machines and microwaves to provide alert or status sounds.
• Toys and Games: Integrated into toys and electronic games to generate sound effects and music.

Advantages

• Sound Customization: Can generate a wide range of sounds and tones by varying the input signal, allowing for complex sound generation.
• Cost-Effective: Generally inexpensive and widely available.
• Flexible Integration: Easily controlled by microcontrollers and other digital circuits to produce specific sound patterns.

Disadvantages

• Requires External Circuitry: Needs an external oscillating signal, making the circuit design more complex compared to using an active buzzer.
• Dependent on Input Signal: Sound quality and volume can significantly vary based on the input signal's characteristics.

Example Connection

To use a passive buzzer with a microcontroller like an Arduino:
 

1. Connect the positive terminal of the passive buzzer to a PWM-capable digital pin on the microcontroller.
2. Connect the negative terminal to the ground (GND) of the microcontroller.
3. Use the microcontroller to generate a PWM signal or oscillating signal to drive the buzzer.

Example Code for Arduino

int buzzerPin = 9; // PWM-capable pin
void setup() {
  pinMode(buzzerPin, OUTPUT);
}
void loop() {
  tone(buzzerPin, 1000); // Generate 1kHz tone
  delay(1000);           // Wait for 1 second
  noTone(buzzerPin);     // Stop the tone
  delay(1000);           // Wait for 1 second
}

This simple code generates a 1kHz tone for 1 second, followed by a 1-second silence, repeating indefinitely.