The **MAH12TCG-R** is a specific model of a **Miniature Magnetic Buzzer** (or Magnetic Transducer), commonly used in electronics to provide audible alerts. It is designed for surface mount technology (SMT) applications. ### 1. Technical Specifications The following table summarizes the key electrical and physical characteristics typically associated with the MAH12TCG-R: | Parameter | Value/Description | | :--- | :--- | | **Type** | Magnetic Transducer (External Drive) | | **Rated Voltage** | 1.5V - 3.0V (Standard operating range) | | **Operating Voltage** | 1.0 ~ 5.0 Vp-p | | **Rated Current** | Max 70mA - 80mA (at rated voltage) | | **Sound Pressure Level (SPL)** | Min 85dB at 10cm | | **Resonant Frequency** | 2,700 Hz (approx.) | | **Coil Resistance** | 16 $\pm$ 3 $\Omega$ | | **Mounting Type** | Surface Mount (SMD) | | **Dimensions** | ~ 12mm x 12mm x 9mm | --- ### 2. Key Electronic Components & Working Principle Unlike an "indicator" (which has internal circuitry to make a sound when DC is applied), the **MAH12TCG-R** is a **transducer**. This means it requires an external oscillating signal to function. * **The Coil:** A copper wire winding inside the plastic housing. When an AC signal or a PWM (Pulse Width Modulation) signal passes through, it creates a fluctuating magnetic field. * **The Magnet:** A permanent magnet provides a static magnetic field. * **The Diaphragm:** A thin metal disk that is attracted and released rapidly by the interaction of the coil's magnetic field and the permanent magnet's field. This vibration creates the sound waves. ### 3. Application Circuitry To drive the MAH12TCG-R, you typically need a transistor-driven circuit, as a microcontroller (like an Arduino or STM32) cannot provide enough current directly from its I/O pins. ```cpp // Example Arduino Pseudocode to drive the buzzer int buzzerPin = 9; // Connected to the base of a transistor void setup() { pinMode(buzzerPin, OUTPUT); } void loop() { tone(buzzerPin, 2700); // Send 2.7kHz square wave delay(500); noTone(buzzerPin); delay(500); } ``` ### 4. Comparison: Transducer vs. Indicator | Feature | MAH12TCG-R (Transducer) | Active Buzzer (Indicator) | | :--- | :--- | :--- | | **Drive Signal** | Requires PWM / Square Wave | Requires simple DC Voltage | | **Frequency Control** | Variable (can play different tones) | Fixed frequency | | **Circuit Complexity** | Higher (needs oscillator) | Lower (Plug and Play) | ---