SFM-20B Piezo Buzzer Alarm 3-24VDC 95dB 23x12mm The SFM-20B Piezo Buzzer Alarm is an active piezoelectric sounder that generates a continuous tone when supplied with a DC voltage between 3V and 24V. It integrates the drive circuit inside the housing, so no external oscillator is required, making it suitable for direct connection to microcontrollers, alarm outputs, and low‑power DC supplies. The unit uses a molded ABS plastic body with two insulated leads and mounting ears, providing a robust and easy‑to‑install solution for panel or enclosure‑mounted alarms. Features: Active piezoelectric design with built-in drive circuit for easy activation. Wide operating voltage range of 3-24VDC for versatile power compatibility. High sound pressure level up to 95dB for effective audible alerts. Compact dimensions of 23mm diameter and 12mm height for space-saving installation. Two mounting holes and pre-attached wires for simple mounting and connection. Specifications: Parameter Value Model SFM-20B. Type Active piezoelectric buzzer, continuous tone. Operating Voltage 3-24VDC. Rated Voltage 12VDC. Sound Pressure Level 95dB Frequency 3300-3900Hz(±500Hz). Current Consumption 10-12mA Body Diameter 22-23mm. Body Height 10-12mm. Wire Length ≈90mm. Mounting Hole Spacing 30mm center‑to‑center. Housing Material ABS plastic, black. Applications: Audible alerts in security and alarm systems. Notification sounds in electronic toys and gadgets. Warning signals in automotive electronic equipment. Feedback tones in computers, printers, and copiers. Status indicators in timers and access control devices. Sound devices in DIY Arduino and IoT projects. Package Include: 1x SFM-20B Piezo Buzzer Alarm 3-24VDC 95dB 23x12mm. Documents: Certification
