The **5ET3.15-R** is a specific ceramic-bodied subminiature fuse, commonly manufactured by **Bel Fuse Inc.** This electronic component is designed to provide overcurrent protection for compact electronic circuits. ### 1. Key Technical Specifications The part number follows a specific nomenclature that defines its electrical characteristics: | Characteristic | Specification | | :--- | :--- | | **Part Series** | 5ET | | **Current Rating** | 3.15 Amperes (3.15A) | | **Voltage Rating** | 250V AC | | **Fuse Type** | Time-Lag (Slow Blow) / High Breaking Capacity | | **Mounting Type** | Radial Lead (Through-Hole) | | **Body Material** | Ceramic | | **Dimensions** | Approx. 8.35mm x 7.7mm (Subminiature) | --- ### 2. Physical Design and Packaging * **Form Factor:** It is a "brick" or "square" style radial lead fuse. The "R" at the end of the part number typically denotes **Radial leads**, making it suitable for direct soldering onto Printed Circuit Boards (PCBs). * **Ceramic Body:** Unlike glass fuses, the ceramic body provides higher breaking capacity, meaning it can safely interrupt higher fault currents without the body shattering. * **Lead Spacing:** Usually features a standard 5.08mm lead spacing for easy integration into standard PCB layouts. --- ### 3. Functional Characteristics * **Slow Blow (Time-Lag):** This fuse is designed to withstand temporary "inrush" currents (spikes that occur when a device is first turned on) without blowing. It will only open the circuit if the overcurrent persists for a specific duration. * **Breaking Capacity:** It is rated for high interrupting ratings (often up to 100A or 150A at 250V AC), which is crucial for safety in power supply applications. --- ### 4. Common Applications Due to its 250V rating and slow-blow nature, the 5ET3.15-R is frequently found in: * **Power Supplies:** Primary side protection for AC/DC adapters. * **Consumer Electronics:** Televisions, monitors, and chargers. * **Industrial Equipment:** Controllers and small motorized appliances. * **LED Drivers:** Protecting against surges in lighting circuitry. --- ### 5. Part Number Breakdown (Bel Fuse Standard) ```text 5ET 3.15 - R | | | | | +-- Lead Style: Radial | +---------- Amperage: 3.15 Amps +--------------- Series Name: Time-lag, high breaking capacity ```