The **3AG300-R** is a specific type of electronic component belonging to the **Small Dimension Fuse** family. Specifically, it is a 3AG (Size 0) fast-acting fuse designed for circuit protection. ### 1. Key Technical Specifications The "3AG" designation refers to the physical dimensions, while the "300" typically refers to the current rating, and the "R" indicates RoHS compliance. | Parameter | Specification | | :--- | :--- | | **Type** | Cartridge Fuse | | **Size Designation** | 3AG (Equivalent to 1/4" x 1-1/4" or 6.3mm x 32mm) | | **Current Rating** | 300mA (0.3 Amperes) | | **Voltage Rating** | Typically 250V AC | | **Response Characteristic** | Fast-Acting (F) | | **Body Material** | Glass | | **Termination Style** | Cartridge (Ferrule) | --- ### 2. Part Number Breakdown Understanding the nomenclature helps identify the exact physical and electrical properties: * **3AG:** This is a North American standard for glass fuses measuring **1.25 inches in length** and **0.25 inches in diameter**. * **300:** Represents the Rated Current. In this context, it stands for **300 milliamperes**. * **-R:** Stand for **RoHS Compliant**, meaning the part is manufactured without lead or other restricted hazardous substances. --- ### 3. Construction and Materials The 3AG300-R is built to provide visible circuit protection: * **Glass Tube:** The transparent body allows for easy visual inspection to see if the internal filament has melted (blown). * **Nickel-Plated Brass Caps:** The end caps provide high conductivity and corrosion resistance. * **Filament:** A precision-calibrated wire or strip designed to melt when the current exceeds 300mA for a specific duration. --- ### 4. Common Applications Due to its low current rating and fast-acting nature, this fuse is commonly found in: 1. **Consumer Electronics:** Power supplies for radios, older televisions, and hi-fi audio equipment. 2. **Test Equipment:** Multimeters and oscilloscopes where sensitive internal components need immediate protection from overcurrent. 3. **Industrial Controls:** Low-power control circuits and PLCs.