The **5VT1.25-R** is a specific model of a subminiature, slow-blow (time-delay) fuse manufactured by **Bel Fuse Inc.** This part is widely used in consumer electronics and industrial power supplies to provide overcurrent protection. ### 1. Technical Specifications The part number follows a specific nomenclature that defines its electrical characteristics: | Parameter | Specification | | :--- | :--- | | **Fuse Type** | Subminiature Radial Lead (Slow Blow / Time Delay) | | **Current Rating** | 1.25 Amperes | | **Voltage Rating (AC)** | 250 Volts | | **Interrupting Rating** | 35A @ 250V AC / 100A @ 125V AC | | **Body Material** | Thermoplastic (UL 94 V-0 Flammability rated) | | **Lead Material** | Tin-plated Copper | | **Operating Temperature** | -55°C to +125°C | --- ### 2. Breakdown of the Part Number Understanding the code helps in identifying replacements or similar components: * **5VT**: Refers to the series (Radial Lead, Time-Delay, 5x5mm approx. size). * **1.25**: Represents the Ampere rating (1.25A). * **-R**: Indicates **RoHS Compliance** (Lead-free). --- ### 3. Key Features and Applications The 5VT series is designed for space-constrained PCB (Printed Circuit Board) layouts. * **Time-Delay Function:** Unlike "Fast-Acting" fuses, this model can withstand temporary surges (inrush current) without blowing. This is crucial for devices with capacitors or motors that draw more power at startup. * **Form Factor:** It is a "Radial" fuse, meaning the pins come out of the bottom, allowing it to stand vertically on a circuit board to save horizontal space. * **Common Uses:** * Battery chargers. * Power supplies (AC/DC adapters). * Set-top boxes and monitors. * Industrial controllers. --- ### 4. Circuit Diagram Representation In a schematic, this part is represented by a standard fuse symbol with the following attributes: ```text F1 (1.25A) ---[ ~~~~~~~~ ]--- 5VT1.25-R ```