The **LOR3-R0025-D** is a high-precision, low-resistance current sensing resistor, typically manufactured by companies like **Lian-Sheng (LSR)** or similar specialized resistive component firms. It is designed specifically for power management and current monitoring applications. ### 1. Part Number Breakdown While naming conventions can vary slightly by manufacturer, the code generally breaks down as follows: | Segment | Meaning | Description | | :--- | :--- | :--- | | **LOR** | Series Prefix | Open-frame or Metal Element Current Shunt Resistor. | | **3** | Power Rating | Typically represents **3 Watts** of power dissipation. | | **R0025** | Resistance Value | **0.0025 Ohms** (or 2.5 mΩ). | | **D** | Tolerance | Represents **±0.5%** precision (D-class). | --- ### 2. Technical Specifications These parts are engineered to handle high current loads while maintaining high accuracy. * **Resistance:** 2.5 Milliohms ($2.5 m\Omega$). * **Power Rating:** 3W at $70^\circ C$ (ambient). * **Tolerance:** $\pm 0.5\%$. * **Temperature Coefficient (TCR):** Usually very low (e.g., $\pm 50 ppm/^\circ C$ or better) to prevent resistance drift as the part heats up. * **Material:** Often constructed from a Manganese-Copper (Manganin) or Ni-Cr alloy element for thermal stability. --- ### 3. Key Features & Applications #### Features * **Low Inductance:** The metal element construction ensures minimal inductive interference, making it ideal for high-frequency switching power supplies. * **High Stability:** Designed to withstand high pulse currents without permanent shifts in resistance. * **Heat Dissipation:** Often features a "raised" or "open-frame" lead design to allow airflow underneath the component. #### Common Applications 1. **Battery Management Systems (BMS):** Monitoring charge and discharge cycles in Lithium-ion packs. 2. **DC-DC Converters:** Providing feedback loops for current-mode control. 3. **Motor Drives:** Sensing phase current to protect against overcurrent conditions. 4. **Power Inverters:** Used in renewable energy systems (Solar/Wind) to measure output current. --- ### 4. Typical Footprint (Radial/Through-Hole) The "LOR" series usually refers to a through-hole component with a rectangular metal body and two sturdy leads. ```text _______ | | <-- Resistive Element (Manganin) |_______| | | | | <-- Heavy-gauge Copper Leads ``` ---