The **S501-2-R** is a specific model of electronic fuse manufactured by **Eaton (formerly Bussmann)**. It belongs to the S501 series, which consists of high-quality, fast-acting miniature glass tube fuses. --- ### 1. Technical Specifications The part number "S501-2-R" can be broken down to understand its electrical characteristics: | Parameter | Specification | | :--- | :--- | | **Series** | S501 (5x20mm Miniature Fuse) | | **Current Rating** | 2 Amperes (2A) | | **Voltage Rating** | 250 VAC | | **Speed/Characteristic** | Fast-Acting (F) / Quick Blow | | **Material** | Glass Tube with Nickel-plated Brass Endcaps | | **Interrupting Rating** | 35A at 250Vac | | **RoHS Compliant** | Yes (indicated by the "-R" suffix) | --- ### 2. Physical Dimensions This fuse follows the standard international metric sizing for small electronic equipment: * **Diameter:** 5 mm * **Length:** 20 mm * **Form Factor:** Cylindrical cartridge --- ### 3. Key Features and Behavior * **Fast-Acting:** Unlike "Slow-Blow" (Time-Delay) fuses, the S501-2-R is designed to open very quickly when an overcurrent occurs. This is critical for protecting sensitive semiconductor components (like ICs or transistors) that cannot withstand even brief surges. * **Low Breaking Capacity:** Being a glass fuse, it has a lower interrupting rating compared to ceramic versions. It is designed for low-energy circuits. * **Visible Element:** Because the body is made of glass, it is easy to visually inspect whether the internal filament has melted (blown). --- ### 4. Common Applications The S501-2-R is found in a wide variety of consumer and industrial electronics, including: 1. **Power Supplies:** Protecting the input stage of AC/DC adapters. 2. **Consumer Electronics:** Televisions, audio equipment, and chargers. 3. **Test Equipment:** Multimeters and oscilloscopes. 4. **Appliances:** Control boards for small household appliances. --- ### 5. Identification (The Suffix "-R") The **-R** at the end of the part number is crucial for modern manufacturing. It signifies that the part is **RoHS compliant**, meaning it is manufactured without hazardous substances like lead, making it suitable for global distribution and environmentally friendly disposal.