How to Use Buzzer: Examples, Pinouts, and Specs

A buzzer is an audio signaling device that produces sound when an electric current passes through it. It is widely used in various electronic applications to provide audible alerts or notifications. Buzzers are commonly found in alarms, timers, household appliances, and embedded systems. They are available in two main types: active buzzers, which generate sound when powered, and passive buzzers, which require an external signal to produce sound.

Below are the general technical specifications for a typical buzzer. Note that specific values may vary depending on the manufacturer and model.

• Operating Voltage: 3V to 12V (commonly 5V)
• Current Consumption: 10mA to 50mA
• Sound Frequency: 2 kHz to 4 kHz (typical)
• Sound Pressure Level (SPL): 85 dB to 100 dB at 10 cm
• Type: Active or Passive
• Operating Temperature: -20°C to 70°C

The buzzer typically has two pins, as described below:

Note: For active buzzers, simply applying a voltage will produce sound. For passive buzzers, a PWM (Pulse Width Modulation) signal is required to generate sound.

1. Identify the Type of Buzzer: Determine whether the buzzer is active or passive. Active buzzers are easier to use as they only require a DC voltage, while passive buzzers need a PWM signal.
2. Connect the Pins:
   • Connect the positive pin of the buzzer to the power supply or control signal (e.g., a microcontroller pin).
   • Connect the negative pin to the ground (GND) of the circuit.
3. Power the Buzzer:
   • For an active buzzer, apply the appropriate voltage (e.g., 5V) to the positive pin to produce sound.
   • For a passive buzzer, generate a PWM signal from a microcontroller to drive the buzzer.

Below is an example of how to connect and control a passive buzzer using an Arduino UNO.

• Connect the positive pin of the buzzer to Arduino digital pin 9.
• Connect the negative pin of the buzzer to the GND pin of the Arduino.

// Example code to control a passive buzzer with Arduino UNO
// This code generates a tone on the buzzer using the tone() function.

#define BUZZER_PIN 9  // Define the pin connected to the buzzer

void setup() {
  pinMode(BUZZER_PIN, OUTPUT);  // Set the buzzer pin as an output
}

void loop() {
  tone(BUZZER_PIN, 1000);  // Generate a 1 kHz tone on the buzzer
  delay(1000);             // Wait for 1 second
  noTone(BUZZER_PIN);      // Stop the tone
  delay(1000);             // Wait for 1 second
}

• Voltage Compatibility: Ensure the operating voltage of the buzzer matches the power supply or control signal.
• Current Limitation: If the buzzer draws more current than the microcontroller pin can supply, use a transistor or MOSFET as a driver.
• Sound Level: Place the buzzer in an open area for maximum sound output. Avoid obstructing the sound hole.
• Type Selection: Use an active buzzer for simple applications and a passive buzzer for more control over sound frequency and patterns.

1. No Sound from the Buzzer:

   • Cause: Incorrect wiring or insufficient voltage.
   • Solution: Verify the connections and ensure the power supply matches the buzzer's operating voltage.

2. Low or Distorted Sound:

   • Cause: Insufficient current or obstructed sound hole.
   • Solution: Check the current supply and ensure the buzzer is not blocked.

3. Buzzer Not Responding to PWM Signal:

   • Cause: Using an active buzzer instead of a passive one.
   • Solution: Confirm the type of buzzer and use a passive buzzer for PWM control.

4. Overheating:

   • Cause: Exceeding the voltage or current rating.
   • Solution: Use a resistor or driver circuit to limit the current.

• Q: Can I use a buzzer with a 3.3V microcontroller?
  A: Yes, but ensure the buzzer operates at 3.3V. If not, use a transistor or MOSFET to drive the buzzer with a higher voltage.

• Q: How do I generate different tones with a passive buzzer?
  A: Use the tone() function in Arduino to generate different frequencies, which correspond to different tones.

• Q: Can I use a buzzer for continuous sound?
  A: Yes, for an active buzzer, simply apply a constant voltage. For a passive buzzer, generate a continuous PWM signal.

• Q: What is the difference between active and passive buzzers?
  A: Active buzzers have an internal oscillator and produce sound when powered. Passive buzzers require an external signal to generate sound.