Sound hole (open)+ markBody · Ø 12 × 8.5 mmPins (+ long) · 7.6 mm spacing

Black cylindrical body, green circuit board visible on the underside, two legs
≈ 12 mm diameter; a bit lower than the active type

Outputs

Passive buzzer

In simple terms

What is this?

A small membrane with no sound of its own that turns incoming vibration into sound. Like a drum; you provide the rhythm.

What is it for?

Plays different notes when you send different frequencies; you can make a melody.

Where do you see it?

In toys and cards that play a tune.

How do you spot it?

A cylinder similar to an active buzzer; look underneath and you see a light green board, and one pin has a plus sign.

Caution:

Connect it straight to a battery and you only hear a click; give it a changing signal instead.

Technical definition

A buzzer with no oscillator of its own that turns the incoming signal into sound. Give it DC and you hear only a click; give it a square wave and it sounds at that frequency. This way it can play different notes and melodies.

DrivingSquare wave (PWM)

Resonance≈2–4 kHz

Voltage3–5 V

Schematic symbol Same in IEC and ANSI

IEC 60617: the drawing style used in Türkiye and Europe.

Pins 2

1Pin 1 (marked +)Signal or transistor output1

2Pin 2GND2

Features typical

Driving: Square wave / PWM
Resonance: ≈2–4 kHz (depends on model); loudest here
Voltage: 3–5 V
Type: Electromagnetic or piezo
Example part: 12 mm passive buzzer (green board on the underside)

Common mistakes

Applying DCA passive buzzer stays silent at a constant voltage; in the electromagnetic type, the coil also draws current for nothing.

Driving directly from a pinAn electromagnetic type has a low coil resistance. Drive it with a transistor to protect the pin.

Test with a multimeter

Test whether this part is good with the multimeter on the measurement screen.

Take a measurement

Where it is used

Playing a melodyAlerts in different tonesSimple piano projectTone generator with 555