The **5HF800-R** is a specific type of electronic component, primarily known as a **Subminiature Quick-Acting Fuse**. It is part of the "5HF" series manufactured by Bel Fuse Inc. Below is a detailed breakdown of its electronic specifications and characteristics. --- ## 1. Core Technical Specifications The "R" suffix in the part number typically denotes **RoHS compliance** (Restriction of Hazardous Substances). | Parameter | Specification | | :--- | :--- | | **Fuse Type** | Fast-Acting (Quick-Acting) | | **Current Rating** | 800 mA (0.8 Amps) | | **Voltage Rating (AC)** | 250 V | | **Body Material** | Ceramic | | **Form Factor** | 5x20 mm (Standard Miniature Size) | | **Interrupting Rating** | 1500A @ 250V AC | | **Resistance (Cold)** | Approximately 0.150 - 0.200 Ohms | --- ## 2. Key Electronic Features ### A. Fast-Acting Characteristic Unlike "Slow-Blow" (Time-Delay) fuses, the 5HF800-R is designed to open the circuit almost instantly when the current exceeds the 800mA threshold. This is critical for protecting sensitive semiconductor components (like ICs or transistors) that cannot withstand even short durations of overcurrent. ### B. High Interrupting Capacity The ceramic body construction allows this fuse to have a higher breaking capacity compared to glass fuses. It can safely interrupt a short circuit current of up to **1500 Amps** without the fuse body shattering. ### C. Construction * **Tube:** High-grade ceramic for thermal stability. * **End Caps:** Nickel-plated brass for high conductivity and corrosion resistance. * **Filament:** Precision-engineered wire designed to melt at a specific $I^2t$ (Ampere-squared seconds) value. --- ## 3. Common Applications Due to its small size and fast response time, the 5HF800-R is commonly found in: 1. **Power Supplies:** Protecting the input stage of small electronic devices. 2. **Test Instruments:** Protecting internal circuitry in multimeters or oscilloscopes. 3. **Industrial Controls:** Used in PLC (Programmable Logic Controller) modules. 4. **Consumer Electronics:** Chargers, monitors, and audio equipment. --- ## 4. Part Number Decoder (5HF Series) To understand the nomenclature: * **5HF:** Series name (Ceramic Tube, Fast-Acting, 5x20mm). * **800:** Current rating (800 Milliamps). * **-R:** RoHS compliant (Lead-free). ---