3-24V Active Buzzer 95dB SFM-27🚨

The SFM-27 Active Buzzer is a compact, high-performance piezoelectric sounder with a built-in oscillator, engineered to deliver a loud, clear continuous tone for emergency and security applications. Designed for DC 3–24 V operation (with 12 V recommended), it’s ideal for integration into Arduino, Raspberry Pi, and other microcontroller-based projects via a simple driver stage. Sound intensity increases with supply voltage, providing flexible performance across a range of systems and electronics modules.

🔧 Key Features and Specifications

• Model: SFM-27
• Operating Voltage: DC 3–24 V (recommended: 12 V)
• Working Current: 20 mA (typical)
• Sound Level: 95 dB at DC 12 V
• Operating Temperature Range: -20°C to +80°C
• Colour: Cream
• Dimensions: Print: 30 mm; Height: 15 mm; Mounting holes: 40 mm; Earpiece: 48 mm
• Cable Length: 10 cm
• Weight: 16 g
• Type: Active buzzer (built-in oscillator for continuous tone)

🔌 Compatibility and Integration

This active buzzer module runs directly from a DC supply and does not require an external tone generator. For Arduino, Raspberry Pi, or other microcontroller boards, switch the buzzer’s supply using a small NPN transistor or logic-level MOSFET when operating at 12 V (or above logic voltage). Use a suitable series resistor or driver if controlling from lower logic levels. Observe polarity and never exceed 24 V DC.

📈 Typical Applications

• Security alarms, intrusion detectors, and emergency warning systems
• Industrial panels, fault indicators, and process alerts
• DIY electronics projects and educational labs
• Automation modules, power supply fault beepers, and battery monitors

📝 Notes and Best Practices

• Sound level increases with applied voltage; 12 V yields approximately 95 dB.
• Mount to a rigid surface and keep the earpiece unobstructed for maximum acoustic output.
• Ensure correct wiring and polarity; use appropriate insulation and strain relief on the 10 cm cable.
• Suitable for operation across -20°C to +80°C in most indoor and protected outdoor enclosures.

📦 Package Contents

1 × SFM-27 90 dB Buzzer