The **S500-1-R** is a specific model of a subminiature, fast-acting glass tube fuse manufactured by **Eaton (formerly Bussmann)**. It is a critical passive electronic component used for overcurrent protection. --- ### 1. Key Technical Specifications The following table summarizes the primary electrical and physical characteristics of the S500-1-R: | Parameter | Specification | | :--- | :--- | | **Current Rating** | 1 Amp (1A) | | **Voltage Rating (AC)** | 250 VAC | | **Interrupting Rating** | 35A at 250 VAC | | **Fuse Type** | Fast-Acting / Quick-Acting (F) | | **Material** | Glass Tube with Nickel-plated Brass Endcaps | | **Dimensions** | 5mm x 20mm (Standard Small Cartridge) | | **Resistance** | ~0.115 Ohms (Typical Cold DCR) | | **Compliance** | RoHS Compliant, IEC 60127-2 | --- ### 2. Functional Description The S500-1-R is designed to protect sensitive electronic circuits. Its primary roles include: * **Fast-Acting Characteristic:** Unlike "Time-Delay" (Slo-Blo) fuses, this model is designed to open (blow) very quickly when the current exceeds 1A. This is vital for protecting components like semiconductors (IC chips, transistors) that cannot withstand even brief surges. * **Physical Form Factor:** The **5x20mm** size is one of the most common fuse standards globally, making it easily replaceable in standard fuse holders or PCB-mounted clips. * **"R" Suffix:** In the Eaton/Bussmann naming convention, the "R" indicates that the part is **RoHS compliant**, meaning it is manufactured without hazardous substances like lead. --- ### 3. Common Applications Due to its 1A rating and fast response time, the S500-1-R is typically found in: 1. **Consumer Electronics:** Power supplies for laptops, printers, and monitors. 2. **Industrial Equipment:** Control circuits and PLC (Programmable Logic Controller) protection. 3. **Test Equipment:** Multimeters and oscilloscopes often use this size and rating for internal protection. 4. **Lighting:** Ballasts and LED drivers. --- ### 4. Selection Criteria (Replacement Note) If you are replacing an S500-1-R, ensure the replacement meets these three criteria: 1. **Dimensions:** Must be 5x20mm. 2. **Amperage:** Must be 1A (lower may blow prematurely; higher may damage the device). 3. **Speed:** Must be "Fast-Acting" (usually marked with an **'F'**). Do not replace with a 'T' (Time-delay) fuse.