HC12G-04B-G Passive Buzzer 1-3V

The HC12G-04B-G is a passive buzzer suitable for 1V–3V DC systems. It produces a  2731 Hz tone when driven with a square wave signal. 

Technical Specifications

• Dimensions: Ø12 x 7.5 mm
  Rated Voltage: 1.5 V
  Operating Voltage: 1 ~ 3 V
  Rated Frequency: 2731 Hz
  Rated Current: <= 70 mA
  SPL (sound pressure level) at 10cm: >= 88 dB
•  
• Usage Note

This is a passive buzzer. It must be driven by a square wave signal, such as using PWM from an Arduino or similar microcontroller. 

Arduino code: 

#define buzzerPin 9

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

void loop() {
 tone(buzzerPin, 4000);  // 4 kHz frekans
 delay(500);
 noTone(buzzerPin);
 delay(500);
} 

 Note: Passive vs Active Buzzer

• A passive buzzer needs a square wave signal (like from a microcontroller PWM).
• An active buzzer has a built-in oscillator and works with direct DC power.