The **HPR-24-R** is a high-performance, chassis-mount power resistor commonly used in industrial and military-grade electronics. It is designed to dissipate significant heat while maintaining a compact footprint. --- ### 1. Key Technical Specifications The electrical characteristics define how this part functions within a circuit: | Parameter | Typical Value / Range | | :--- | :--- | | **Power Rating** | 24 Watts (with appropriate heatsink) | | **Resistance Tolerance** | ±1%, ±5%, or ±10% | | **Temperature Coefficient** | ±50 ppm/°C to ±100 ppm/°C | | **Operating Temperature** | -55°C to +155°C | | **Mounting Style** | Chassis Mount (Bolted) | --- ### 2. Internal Composition and Build The HPR-24-R series is engineered for durability and thermal efficiency: * **Resistive Element:** Typically utilizes a **wirewound** or **thick film** element. Wirewound versions are preferred for high-pulse stability, while thick film versions offer lower inductance. * **Encapsulation:** The core is encased in an **Anodized Aluminum housing**. This housing protects the element from environmental factors and provides the surface area needed for heat transfer. * **Termination:** Features rugged screw terminals or solder lugs (depending on the specific sub-model) to ensure low-resistance connections even under vibration. --- ### 3. Electronic Functionality The "HPR" (High Power Resistor) designation signifies its primary roles in a system: 1. **Dynamic Braking:** Absorbing excess energy from motors to slow them down safely. 2. **Current Sensing:** Used in power supplies to monitor high current flow by measuring the voltage drop across the resistor. 3. **Inrush Limiting:** Protecting sensitive components from the initial surge of current when a device is powered on. 4. **Dummy Load:** Simulating an electrical load during the testing of power amplifiers or power supplies. --- ### 4. Thermal Management Requirements Because this is a 24W resistor, it cannot dissipate its full rated power in free air. It relies on **Conduction Cooling**. * **Heatsink dependency:** To reach the 24W rating, it must be mounted to a metal plate (typically aluminum). * **Thermal Compound:** It is standard practice to apply thermal grease between the resistor base and the chassis to eliminate air gaps.