+ (positive lead — the longer leg, under the "+" moulded on the top)
विनिर्देश
टाइप
Active (built-in oscillator, DC) or passive (needs square wave)
Rated voltage
5 V typical; 3.3 V and 12 V versions exist
करंट
≤ 30 mA (5 V active type)
Resonant frequency
≈2.3 kHz (common 12 mm active type)
Sound level
≈85 dB at 10 cm (12 mm active type)
आकार
12 mm Ø × 9.5 mm (common 12 mm type)
पोलैरिटी
Longer leg = +
नोट्स
Active buzzers just need DC applied and buzz on their own; passive buzzers need a driven square wave (PWM) at the desired frequency. Same canister, so test: a passive one only clicks on DC.
An active buzzer draws ~30mA — fine straight from a GPIO on most boards, but add a transistor for the louder 12V types.
