The **E-122-R** typically refers to a high-performance **Electromagnetic Buzzer** (specifically a Transducer or Indicator) often used in telecommunications, medical equipment, and consumer electronics. Below is the technical breakdown of its electronic components and characteristics. --- ### 1. Technical Specifications The "R" suffix often indicates "RoHS compliant" or a specific "Rear-entry/Radial" mounting style depending on the manufacturer (such as DB Products or Kingstate). | Parameter | Typical Value | | :--- | :--- | | **Rated Voltage** | 1.5V - 12V DC (Model dependent) | | **Operating Voltage** | 1.0V ~ 15V DC | | **Current Consumption** | Max 30mA - 40mA | | **Sound Pressure Level (SPL)** | 80dB - 85dB at 10cm | | **Resonant Frequency** | 2,000Hz - 2,400Hz | | **Operating Temperature** | -20°C to +70°C | --- ### 2. Internal Electronic Components An electromagnetic buzzer like the E-122-R consists of several key parts that work together to convert electrical energy into sound: * **Electromagnet (Coil):** A wire coil wound around a metal core. When current passes through, it creates a magnetic field. * **Permanent Magnet:** Provides a static magnetic field that interacts with the electromagnet. * **Vibrating Diaphragm:** A thin metal disk (often containing a small iron piece) that is physically moved by the fluctuating magnetic field. * **Housing (Casing):** Usually made of PBT or ABS plastic, designed with an acoustic chamber to amplify the sound output. * **Terminals/Pins:** "R" models often feature PCB-mount pins for direct soldering. --- ### 3. Circuit Integration Since the E-122-R is a **transducer**, it generally requires an external drive circuit to function. It does not "beep" just by applying DC power; it needs an oscillating signal. #### Basic Driver Circuit Example To drive this part using a microcontroller (like an Arduino), a simple NPN transistor circuit is recommended: ```cpp // Basic Arduino Tone Generation for E-122-R int buzzerPin = 9; void setup() { pinMode(buzzerPin, OUTPUT); } void loop() { tone(buzzerPin, 2400); // Send a 2.4KHz signal delay(500); noTone(buzzerPin); // Stop sound delay(500); } ``` --- ### 4. Application Areas * **Security Systems:** Feedback pings for keypads. * **Medical Devices:** Pulse monitors or alarm indicators. * **Industrial Controls:** Status alerts for PLC systems. * **Consumer Electronics:** Timers for microwave ovens or washers.