PIEZO BUZZER INSIDE

Circuit

Piezeo electric crystal based buzzer circuit

Program (Arduino -for 20KHz)

void setup() {
    pinMode(13,OUTPUT);
}
void loop() {
    digitalWrite(13,HIGH);
    delayMicroseconds(10);
    digitalWrite(13,LOW);
    delayMicroseconds(12);
}

Waveforms

(Note : attenuation probe *10 used)

voltage wave form across piezeo electric crystal (40v ,Cout =0.1uF , f=4.7KHz)

voltage wave form across piezeo electric crystal (50v  ,Cout =0.01uF , f=4.7KHz)

voltage wave form across piezeo electric crystal (52v  ,Cout=220pF, f=4.7KHz)

voltage wave form across piezeo electric crystal (28v  ,Cout =0.01uF , f=20KHz)