The **AI-4228-TWT-R** is a high-output, 12VDC electromagnetic audio transducer (buzzer) manufactured by PUI Audio. It is widely used in industrial equipment, security systems, and automotive applications due to its reliability and loud output. --- ### 1. Key Technical Specifications The following table highlights the critical electrical and physical parameters of the component: | Feature | Specification | | :--- | :--- | | **Rated Voltage** | 12 VDC | | **Operating Voltage Range** | 3 ~ 20 VDC | | **Rated Current (Max)** | 10 mA | | **Sound Pressure Level (SPL)** | 98 dBA @ 10cm | | **Resonant Frequency** | 2,800 Hz ± 500 Hz | | **Tone Type** | Continuous | | **Mounting Type** | Through Hole (Flange Mount) | | **Termination** | Wire Leads (140mm) | | **Operating Temperature** | -20°C to +60°C | --- ### 2. Electronic Architecture & Working Principle The AI-4228-TWT-R is an **indicator** type buzzer, meaning it has internal circuitry. * **Integrated Driver:** Unlike "transducers" that require an external AC signal to oscillate, this "indicator" includes an internal oscillation circuit. When a DC voltage (3-20V) is applied, it automatically produces sound. * **Electromagnetic Mechanism:** It utilizes a coil and a magnet. When current flows through the coil, it creates a magnetic field that moves a metal diaphragm at the resonant frequency (2.8 kHz), creating sound waves. * **Efficiency:** With a maximum current draw of only **10mA**, it can be driven directly by many microcontroller GPIO pins (though a transistor buffer is recommended for long-term reliability). --- ### 3. Implementation Circuit (Typical) To integrate this part into a digital system (like an Arduino or ESP32), a simple NPN transistor switch is standard practice: ```cpp // Example: Driving via NPN Transistor // VCC (12V) ---- (+) Buzzer (-) ---- Collector (Transistor) // Base (Transistor) ---- Resistor (1k) ---- GPIO Pin // Emitter (Transistor) ---- GND ``` --- ### 4. Physical Dimensions & Material * **Housing:** Black ABS (Acrylonitrile Butadiene Styrene) material. * **Size:** 41.8mm diameter x 16mm height. * **Weight:** Approximately 15 grams. * **Environmental:** RoHS compliant, designed for rugged environments where high decibel output is necessary for alerts.