The **S500-80-R** is a specific model within the **S500 series** of high-performance, time-delay (slow-blow) glass tube fuses manufactured by **Eaton (formerly Bussmann)**. Below is a detailed breakdown of its electronic specifications and characteristics. ### 1. Core Specifications The S500-80-R is a subminiature fuse designed for circuit protection against overcurrent events. | Property | Specification | | :--- | :--- | | **Current Rating** | 80mA (0.08 Amps) | | **Voltage Rating (AC)** | 250 VAC | | **Fuse Type** | Time-Delay / Slow-Blow (T-type) | | **Body Material** | Glass Tube | | **End Cap Material** | Nickel-plated Brass | | **Size** | 5mm x 20mm | | **Interrupt Rating** | 35A @ 250VAC | | **RoHS Compliant** | Yes (indicated by the "-R" suffix) | --- ### 2. Electronic Characteristics To understand how this part functions in a circuit, we must look at its thermal and electrical behavior: * **Time-Delay (Slow-Blow):** Unlike "fast-acting" fuses, the S500-80-R is designed to withstand temporary surges or "inrush currents." This is crucial for circuits with capacitors or small motors that pull more power momentarily during startup. * **Low Current Sensitivity:** At 80mA, this fuse is designed for precision protection of sensitive electronic components, such as control circuits, small power supplies, or instrumentation. * **Resistance & Voltage Drop:** At such a low amperage, the internal filament has a measurable resistance. When 80mA flows through it, there is a minor voltage drop across the fuse that should be accounted for in precision low-voltage designs. * **Breaking Capacity:** The "35A @ 250VAC" interrupt rating means the fuse can safely clear a short circuit of up to 35 Amperes without the glass tube shattering or exploding. --- ### 3. Part Number Decoding The Eaton/Bussmann part numbering system provides specific details: | Segment | Meaning | | :--- | :--- | | **S500** | Series designation (5x20mm, Time-delay, IEC standard) | | **80** | Rated current (80 milliamps) | | **-R** | Lead-free and RoHS compliant construction | --- ### 4. Common Applications Due to its small form factor and slow-blow nature, the S500-80-R is commonly found in: * **Consumer Electronics:** Power adapters and chargers. * **Industrial:** PLC (Programmable Logic Controller) I/O protection. * **Medical Equipment:** Sensitive diagnostic tools. * **Power Supplies:** Primary side protection for low-wattage SMPS. ---