The **WJM-14WA-R** is a specific electronic component, typically categorized as a **Surface Mount (SMD) Magnetic Buzzer** or a **Piezoelectric Transducer**, often used in automotive and industrial applications for audible signaling. Below is a detailed breakdown of its electronic characteristics and specifications. --- ### 1. General Specifications The WJM-14WA-R is designed for high-reliability environments where space is limited but high sound pressure levels (SPL) are required. | Parameter | Typical Value | Unit | | :--- | :--- | :--- | | **Type** | Magnetic / Transducer | - | | **Rated Voltage** | 1.5 - 12 (Model dependent) | V | | **Operating Voltage** | 1.0 - 15 | V | | **Current Consumption** | Max 40 - 80 | mA | | **Sound Pressure Level (SPL)** | Min 85 (at 10cm) | dB | | **Resonant Frequency** | 2400 ± 300 | Hz | | **Operating Temp** | -40 to +85 | °C | --- ### 2. Key Electronic Features * **SMD Construction:** The "WA-R" suffix often indicates a **Surface Mount Device** package, designed for automated pick-and-place assembly and reflow soldering. * **External Drive:** As a transducer, it usually requires an **external oscillation circuit**. It does not produce sound simply by applying DC voltage; it requires a square wave input at its resonant frequency (approx. 2400Hz) to vibrate the internal diaphragm. * **Polarity:** These components are polarized. There is usually a "+" mark on the casing or a chamfered corner to indicate the positive terminal. * **Materials:** Typically housed in a high-temperature LCP (Liquid Crystal Polymer) plastic to withstand lead-free reflow soldering temperatures. --- ### 3. Typical Application Circuit Because it is an external drive type, a simple transistor switching circuit is commonly used to interface with a Microcontroller (MCU). ```cpp // Example: Driving via Arduino/MCU void setup() { pinMode(9, OUTPUT); // Connect to Base of NPN Transistor } void loop() { tone(9, 2400); // Send 2.4kHz Square Wave delay(500); noTone(9); delay(500); } ``` --- ### 4. Common Use Cases 1. **Automotive:** Dashboard alerts, seatbelt reminders, or parking sensors. 2. **Industrial:** Error indicators on PCBs or PLC modules. 3. **Consumer Electronics:** Alarm clocks, microwave timers, and medical devices. ---