SFM-27 Piezo Buzzer Alarm 3-24VDC 95dB 30x15mm

The SFM-27 Piezo Buzzer Alarm is an active buzzer module that generates a continuous alarm tone whenever a DC voltage within its operating range is applied. Because the oscillator and drive electronics are integrated, it can be powered directly from a DC supply or a digital control line without requiring any external tone-generation circuitry, which simplifies alarm and indicator designs. With a nominal body diameter of about 30mm and a height around 15mm, the buzzer offers strong acoustic output while remaining compact enough for control panels, instrument housings, and embedded enclosures.

Features:
Active piezoelectric buzzer with built‑in oscillation/drive circuit for continuous tone when powered.​
Wide 3-24VDC operating range with 12VDC rated operation for flexible use with logic and power systems.​
High sound pressure level, typically around 95–105dB at 12V depending on distance, suitable for loud alarms.​
Nominal 30mm diameter and about 15–16mm height for compact but high‑output acoustic performance.​
Resonant frequency near 2.5–3.1kHz for a clear, attention‑grabbing tone.
Specifications:
Parameter Value
Model SFM-27 / SFM-27-I
Type Active piezoelectric buzzer, continuous tone
Operating Voltage 3-24 VDC
Rated Voltage 12 VDC
Sound Pressure Level Approx. 95-105 dB (at 12 VDC, measurement distance 10-30 cm)
Resonant Frequency 2500-3100 Hz (±500 Hz)
Rated Current Typically ≤ 15-32 mA
Body Diameter ≈ 30 mm
Body Height ≈ 15-16 mm
Operating Temperature -20°C to +45/60°C
Storage Temperature -20°C to +60°C
Housing Color Black
Sound Type Continuous alarm tone when powered