The **S500-2-R** is a specific electronic component within the **S500 Series of Time-Delay Glass Tube Fuses**, typically manufactured by **Eaton (Bussmann Division)**. It is designed to protect electrical circuits from overcurrent conditions while allowing for temporary surges. ### 1. Key Technical Specifications The part number "S500-2-R" can be broken down to understand its electrical characteristics: | Parameter | Specification | | :--- | :--- | | **Series** | S500 (Time-Delay / Slow Blow) | | **Amperage Rating** | 2 Amps | | **Voltage Rating (AC)** | 250 VAC | | **Construction Material** | Glass Tube with Brass Endcaps | | **Standard Size** | 5mm x 20mm | | **Interrupting Rating** | 35A at 250VAC | | **RoHS Compliant** | Yes (indicated by the "-R" suffix) | --- ### 2. Physical & Material Composition Understanding the physical build is crucial for integration into PCBs or fuse holders: * **Body:** Transparent glass tube. This allows for visual inspection to see if the internal filament has melted (blown). * **Endcaps:** Nickel-plated brass construction provides high conductivity and corrosion resistance. * **Filament:** A specially wound wire designed to withstand short-term "inrush" currents without breaking, but melting if a sustained overload occurs. --- ### 3. Operational Characteristics As a **Time-Delay (Slow-Blow)** fuse, its behavior differs significantly from Fast-Acting fuses: 1. **Inrush Tolerance:** It is ideal for circuits containing motors, transformers, or large capacitors that draw a spike of power when first turned on. 2. **Safety Compliance:** Built to **IEC 60127-2 (Sheet 3)** standards, making it a globally recognized component for power supplies and consumer electronics. 3. **Resistance:** It has a typical DC cold resistance of approximately **0.036 Ohms**. --- ### 4. Common Applications The S500-2-R is found in various electronic devices where 2A protection is required: * **Power Supplies:** Primary side protection for AC/DC adapters. * **LED Drivers:** Protecting the circuitry from grid fluctuations. * **Audio/Video Equipment:** Used in amplifiers and receivers. * **Home Appliances:** Control boards for microwaves or small kitchen tools. --- ### 5. Identification Code Breakdown If you are looking at the fuse markings, here is how to read them: `S500` (Series) + `2` (Current Rating) + `-R` (RoHS Lead-Free Version).