The **WSBS-1AD-R/Q** is a high-precision, low-resistance shunt resistor designed primarily for high-current sensing applications, such as automotive battery management systems (BMS). It is part of the Vishay Dale Power Metal Strip® series. ### 1. Technical Specifications The following table summarizes the key electrical and physical parameters of the WSBS-1AD-R/Q: | Parameter | Specification | | :--- | :--- | | **Resistance Range** | 50 $\mu\Omega$ to 1000 $\mu\Omega$ (Typical) | | **Power Rating** | Up to 36 W (Continuous) | | **Tolerance** | ± 1.0% or ± 5.0% | | **Temperature Coefficient** | < 20 ppm/°C (Resistive Element) | | **Operating Temperature** | -65 °C to +170 °C | | **Construction** | Electron-beam welded Manganin/Aluchrom alloy | --- ### 2. Key Electronic Features #### A. Power Metal Strip® Technology Unlike standard thick-film resistors, this part uses a solid metal alloy as the resistive element. This construction allows it to handle massive current surges without suffering from thermal drift or permanent resistance shifts. #### B. Extremely Low Resistance (Shunt) Because the resistance is in the micro-ohm ($\mu\Omega$) range, it minimizes power loss ($P = I^2R$). This is critical in electric vehicles (EVs) where efficiency and heat management are priorities. #### C. Thermal EMF and Stability The "R/Q" variants are often characterized by: * **Low Thermal EMF:** Minimizes voltage errors caused by temperature gradients across the terminals. * **AEC-Q200 Compliance:** The "Q" in the suffix typically denotes automotive grade qualification, meaning it has passed rigorous stress testing for vibration, thermal shock, and moisture. --- ### 3. Connection and Configuration The physical design is specific to high-current environments: * **Terminals:** Large copper terminals designed for bolting or welding directly to busbars or heavy-gauge wiring. * **Kelvin Connection (4-Terminal Sensing):** In electronic circuits, this part is used with a Kelvin sensing setup. Two terminals carry the high load current, while two smaller sensing points measure the voltage drop ($V = I \times R$) to calculate current accurately via a BMS controller. --- ### 4. Typical Applications 1. **Automotive BMS:** Monitoring state-of-charge (SoC) and state-of-health (SoH) in EV batteries. 2. **Solar Inverters:** Measuring DC string currents. 3. **Industrial Power Supplies:** Overcurrent protection in high-power motor drives.