Active buzzer · Exterior view
Wash label (over the sound hole)+ markBody · Ø 12 × 9.5 mmPins (+ long) · 7.6 mm spacing
Black cylindrical body, sound hole and protective label on top, long leg marked “+”
≈ 12 mm diameter × 9.5 mm high
Outputs

Active buzzer

In simple terms
What is this?

A small alarm with its own sound maker inside. Give it electricity and it always beeps with the same sound.

What is it for?

Gives a single-tone beep when voltage is applied; for alarms and confirmation sounds.

Where do you see it?

Alarm clock, the end-of-cycle beep of a microwave oven.

How do you spot it?

A cylindrical black body with a sound hole on top; the plus leg is marked.

Caution:

Connect plus and minus correctly; do not confuse it with a passive buzzer, which shows a light green board underneath.

Technical definition

An audible alert that carries its own oscillator circuit inside. It sounds at a fixed tone as soon as DC voltage is applied to its terminals in the right direction. Its tone can't be changed; beep rhythms are made by switching it on and off.

Voltage5 V
Current≤ 30 mA
Tone≈2.3 kHz
Schematic symbol Same in IEC and ANSI

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

Pins 2
1Plus (+)Long leg; “+” mark on the body+
2Minus (−)Short leg; GND−
Features typical
Rated voltage
5 V (3 V and 12 V types also exist)
Current
≤ 30 mA
Audio frequency
≈2.3 kHz
Volume
≈85 dB (10 cm)
Polarity
Yes
Example part
12 mm 5 V active buzzer
Common mistakes
Mixing it up with a passive buzzerAn active buzzer’s base is usually resin-sealed; a passive one shows a green circuit board. PWM distorts an active buzzer’s tone.
Connecting it backwardsAn active buzzer has polarity. It stays silent if connected in reverse.
Overloading the pin30 mA may be at the limit for a pin. If it will run for long, drive the buzzer with a transistor.

Test with a multimeter

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

Take a measurement
Where it is used
Alarm and warning soundKey confirmation beepTimer finished signal
Related lessons
Sound with a buzzer
Module 5 · Sensors and outputssoonSwitching with a transistor
Module 4 · Diode and transistorsoon
Try it in the Lab