The **S501-1-R** is a specific model of a glass tube fuse manufactured by **Eaton (Bussmann Series)**. It is a high-performance miniature fuse commonly used to protect electronic circuits from overcurrent and short-circuit conditions. --- ### ## Technical Specifications The following table summarizes the key electrical and physical characteristics of the S501-1-R: | Feature | Specification | | :--- | :--- | | **Current Rating** | 1 Amp (1A) | | **Voltage Rating (AC)** | 250 VAC | | **Fuse Type** | Fast-Acting / Quick-Acting (F) | | **Material** | Glass Tube with Nickel-plated Brass Endcaps | | **Size / Dimension** | 5mm x 20mm (Standard Miniature) | | **Interrupting Rating** | 35A @ 250VAC | | **Resistance (Cold)** | Approximately 0.152 Ohms | | **RoHS Compliant** | Yes (indicated by the "-R" suffix) | --- ### ### Key Characteristics 1. **Fast-Acting (F Speed):** Unlike "Slow-Blow" fuses, the S501-1-R is designed to open very quickly when an overload occurs. This is critical for protecting sensitive semiconductor components (like ICs or transistors) that cannot withstand even brief surges. 2. **The "-R" Suffix:** In the Bussmann numbering system, the "R" stands for **RoHS Compliance**, meaning the part is manufactured without lead or other restricted hazardous substances. 3. **Physical Construction:** It features a transparent glass body, allowing for easy visual inspection to see if the internal filament has melted (blown). --- ### ### Common Applications This fuse is typically found in: * **Power Supplies:** Protecting the input stage of AC/DC adapters. * **Consumer Electronics:** Televisions, audio equipment, and chargers. * **Industrial Controls:** Small control panels and PLC outputs. * **Test Equipment:** Multimeters and signal generators. --- ### ### Installation Note When replacing an S501-1-R, ensure the replacement is also rated for **1A** and **250V**. Using a fuse with a higher current rating (e.g., 2A) will fail to protect the circuit, while using a "Time-Delay" (Slow-Blow) fuse instead of this "Fast-Acting" version could allow damage to occur before the fuse blows.