The **AI-4228-P-C48-R** is a high-performance **piezoelectric audio indicator (buzzer)** manufactured by **PUI Audio**. It is designed for applications requiring high sound output with low power consumption. --- ### 1. Technical Specifications The following table summarizes the core electronic and physical characteristics of the component: | Feature | Specification | | :--- | :--- | | **Technology** | Piezoelectric | | **Input Type** | DC (Internal Circuitry/Indicator) | | **Rated Voltage** | 12 VDC | | **Voltage Range** | 3 ~ 28 VDC | | **Current Consumption** | 8 mA (at Rated Voltage) | | **Sound Pressure Level (SPL)** | 95 dBA @ 30cm | | **Resonant Frequency** | 2,800 Hz ± 500 Hz | | **Tone Type** | Continuous | | **Mounting Type** | Panel Mount with Lead Wires | | **Operating Temperature** | -20°C to +60°C | --- ### 2. Key Internal Parts & Construction The device consists of several critical internal layers that allow it to function directly from a DC power source: * **Piezo Ceramic Element:** The core "motor" of the part. It consists of a ceramic disc bonded to a metal diaphragm. When voltage is applied, the ceramic expands and contracts, vibrating the diaphragm to create sound. * **Internal Oscillator Circuit:** Unlike a "transducer" (which requires an external AC signal), this "indicator" contains a built-in circuit. This circuit converts the incoming DC voltage into the specific frequency (2.8 kHz) needed to drive the piezo element. * **ABS Plastic Housing:** The 42mm diameter casing acts as an acoustic chamber, tuned to mechanically amplify the 2.8 kHz frequency to reach the high 95 dB output. * **Lead Wires:** 28 AWG wires are used for electrical connection, typically color-coded (Red for Positive, Black for Negative). --- ### 3. Application Use Cases Due to its high decibel output and wide voltage range, this part is commonly found in: 1. **Industrial Controls:** Status alarms for machinery. 2. **Security Systems:** Audible alerts for control panels. 3. **Medical Equipment:** High-reliability notification pings. 4. **Marine Electronics:** Water-resistant alerts (when properly mounted). --- ### 4. Circuit Integration Tips * **Polarity:** Since it has internal circuitry, you must observe polarity. Reversing the red and black wires will result in no sound and potentially damage the oscillator. * **Driving with a Microcontroller:** While the current draw is low (8mA), it is often best to drive this through a **BJT (NPN) transistor** or a **MOSFET** if your MCU operates at 3.3V or 5V, as the buzzer performs best at 12V.