The **W2SP-112-R** refers to a high-performance **Electromagnetic Buzzer** (specifically an SMD Washable Transducer) often manufactured by companies like **Star Micronics** or similar acoustic component specialists. Below is the detailed breakdown of its electronic specifications and characteristics. --- ### 1. Key Technical Specifications These parameters define how the part operates within a circuit: | Parameter | Typical Value | Notes | | :--- | :--- | :--- | | **Rated Voltage** | 1.5V - 12V | Varies by sub-model; usually 1.5V or 12V. | | **Current Consumption** | Max 40mA | Depends on the driving frequency. | | **Sound Pressure Level (SPL)** | Min 85 dB @ 10cm | Loudness of the alert. | | **Resonant Frequency** | 2,730 Hz | The frequency where peak volume occurs. | | **Operating Temp** | -40°C to +85°C | Industrial grade temperature range. | | **Driving Method** | External Drive | Requires an external oscillating circuit (PWM). | --- ### 2. Functional Electronic Components The "W2SP" series is a **transducer**, meaning it does not have a built-in oscillator. To make it sound, your circuit must provide a square wave. * **Coil Resistance:** Inside the housing is a fine wire coil. When current passes through, it creates a magnetic field. * **Diaphragm:** A metal disk that is attracted/repelled by the magnetic field, creating sound waves. * **Polarity:** These parts are polarized (+/-). Reversing them may result in significantly lower volume or no sound. --- ### 3. Circuit Integration Since this is an **External Drive** type, it is typically controlled via a Microcontroller (MCU) using a transistor switch. #### **Typical Wiring Diagram Concept** ```text [MCU Pin] ---- [Resistor] ---- [Base of NPN Transistor] | [Buzzer -] <--- [Buzzer +] --- [VCC] | [GND] ``` #### **Key Implementation Tips:** 1. **Flyback Diode:** It is highly recommended to place a diode (like 1N4148) in parallel with the buzzer to protect your transistor from inductive voltage spikes. 2. **PWM Control:** Use a 50% duty cycle square wave at the **Resonant Frequency (approx 2.7kHz)** to achieve the maximum volume. 3. **Washable Design:** The "W" in the prefix usually indicates it is sealed with a removable label, allowing the PCB to be washed after soldering without damaging the acoustic chamber. --- ### 4. Physical Dimensions (SMD) * **Mounting:** Surface Mount Device (SMD). * **Size:** Compact footprint (approx 12mm x 12mm), designed for automated pick-and-place assembly.