The **W2VS-15AB-R2** is a high-performance **rotary variable differential transformer (RVDT)** or a specialized rotary displacement sensor, typically manufactured by companies like **Tamagawa Seiki**. It is designed for high-precision angular position sensing in demanding industrial or aerospace environments. --- ### 1. Key Technical Specifications Below are the typical electronic and mechanical characteristics for this series: | Parameter | Specification (Typical) | | :--- | :--- | | **Type** | Rotary Variable Differential Transformer (RVDT) | | **Input Voltage** | 7V AC (RMS) | | **Input Frequency** | 3 kHz to 10 kHz (Variable) | | **Transformation Ratio** | 0.5 ± 10% | | **Operating Range** | ±40° to ±60° (Model dependent) | | **Linearity** | < ±0.5% FS (Full Scale) | | **Phase Shift** | < 10° | --- ### 2. Internal Electronic Structure The device functions based on electromagnetic induction. It consists of several internal coil windings: * **Primary Winding:** The excitation coil where the AC input voltage is applied. This creates a primary magnetic field. * **Secondary Windings:** Two identical coils placed symmetrically. As the internal rotor turns, the magnetic coupling between the primary and each secondary coil changes. * **Rotor:** A specially shaped ferromagnetic core that rotates, directing the magnetic flux toward the secondary coils based on its angular position. --- ### 3. Operating Principle The sensor outputs an AC voltage that represents the physical angle of the shaft: 1. **Excitation:** An AC carrier signal is fed into the primary. 2. **Induction:** The rotor's position determines how much voltage is induced in the two secondary coils. 3. **Differential Output:** The output is calculated as the difference between the two secondary voltages ($V_{s1} - V_{s2}$). 4. **Signal Conditioning:** To use this in a digital system, the output must be sent to an **R/D Converter (Resolver-to-Digital)** or a synchronous demodulator circuit. --- ### 4. Comparison: RVDT vs. Potentiometer | Feature | W2VS-15AB-R2 (RVDT) | Standard Potentiometer | | :--- | :--- | :--- | | **Contact** | Non-contact (Inductive) | Contact (Wiper/Carbon) | | **Life Span** | Extremely high (No wear) | Limited (Wear and friction) | | **Environment** | High vibration/moisture resistant | Sensitive to dust/vibration | | **Signal Type** | AC Analog | DC Analog | --- ### 5. Application Areas Because of its "R2" designation (often implying high reliability/ruggedization), it is commonly used in: * **Aerospace:** Flight control surface positioning (flaps, rudders). * **Heavy Machinery:** Precise angle control for hydraulic valves. * **Military:** Turret positioning and gimbal stabilization systems.