SFM-20B Active Piezo Buzzer Alarm Speaker DC 3–24V for Arduino
SFM-20B Active Piezo Buzzer Alarm Speaker DC 3–24V for Arduino
SFM-20B Active Piezo Buzzer – High-Decibel Alarm Speaker for Arduino & Electronics Projects
The SFM-20B Active Piezoelectric Buzzer is a compact, high-decibel alarm speaker designed for makers, hobbyists, and engineers. With a wide operating voltage range of DC 3V to 24V, it delivers a continuous, loud tone the moment power is applied — no additional signal generation required. Whether you're building security alarms, timer alerts, or interactive Arduino projects, this buzzer gets the job done reliably and efficiently.
Key Features
- Model: SFM-20B Active Piezoelectric Buzzer
- Operating Voltage: DC 3V – 24V (wide compatibility)
- Type: Active buzzer — produces continuous sound without an external signal
- High Decibel Output: Loud, clear alarm tone ideal for alert and notification applications
- Piezoelectric Design: Low power consumption and long operational lifespan
- Arduino Compatible: Plug-and-play integration with Arduino, Raspberry Pi, ESP32, and other microcontrollers
- Versatile Quantity: Available in packs of 1 to 10 — stock up for multiple projects
- Compact Form Factor: Easy to mount on breadboards or PCBs
What Is an Active Buzzer?
Unlike passive buzzers that require an external frequency signal, an active buzzer has a built-in oscillator circuit. Simply apply power within the rated voltage range and it emits a steady continuous tone instantly. This makes the SFM-20B perfect for beginners and rapid prototyping where simplicity is key.
Typical Applications
- Arduino & microcontroller alarm systems
- Security and intrusion alert circuits
- Timer and countdown notification devices
- DIY electronics and maker projects
- Robotics and automation feedback
- Educational electronics kits
Technical Specifications
| Model | SFM-20B |
| Type | Active Piezoelectric Buzzer |
| Operating Voltage | DC 3V – 24V |
| Sound Type | Continuous Tone |
| Compatibility | Arduino, Raspberry Pi, ESP32, and more |
Made in Mainland China.
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Frequently Asked Questions
Q: What is the difference between an active and passive piezo buzzer?
A: An active buzzer like the SFM-20B has an internal oscillator, so it produces a continuous tone as soon as DC voltage is applied — no external frequency signal needed. A passive buzzer requires a PWM or square wave signal from a microcontroller to generate sound. The SFM-20B is ideal for simple, plug-and-play alarm applications.
Q: Is the SFM-20B compatible with Arduino and Raspberry Pi?
A: Yes! The SFM-20B operates from DC 3V to 24V, making it fully compatible with Arduino (5V), Raspberry Pi (3.3V/5V), ESP32, ESP8266, and virtually any other common microcontroller or development board. Simply connect the positive pin to your digital output pin (or direct power) and the negative pin to ground.
Q: Can I buy multiple units in one order?
A: Absolutely. This listing offers packs ranging from 1 to 10 pieces, so you can order exactly the quantity you need for your project — whether it's a single prototype or a batch build.
Q: Does the buzzer require any programming to work?
A: No programming is required for basic operation. Because it is an active buzzer, applying voltage within the 3–24V DC range is all it takes to start the continuous alarm tone. For on/off control, you can simply use a digital output pin on your microcontroller.