The part number **BK/PCB-3/4-R** refers to a specific type of subminiature fuse manufactured by **Eaton (Bussmann Series)**. This component is widely used for overcurrent protection on printed circuit boards (PCBs). ### Component Overview The **BK/PCB-3/4-R** is a fast-acting, through-hole fuse designed for space-constrained electronics. --- ### Technical Specifications | Parameter | Specification | | :--- | :--- | | **Manufacturer** | Eaton (Bussmann) | | **Series** | PCB Series | | **Current Rating** | 0.75 Amperes (3/4 A) | | **Voltage Rating (AC)** | 250 VAC | | **Fuse Type** | Fast-Acting (F) | | **Mounting Type** | Through-Hole (Radial Leads) | | **Body Material** | Ceramic (typically) | | **RoHS Compliant** | Yes (indicated by the "-R" suffix) | --- ### Key Features and Construction 1. **Form Factor:** It features a rectangular or "brick" style body with radial leads, allowing it to be soldered directly into a PCB without a fuse holder. 2. **Fast-Acting Characteristic:** This fuse is designed to open very quickly when it detects an overload. This protects sensitive semiconductor components that cannot withstand overcurrent for more than a few milliseconds. 3. **High Interrupting Rating:** Despite its small size, it is rated to safely interrupt a significant amount of current (typically up to 50A at 250VAC) without exploding or shattering. 4. **Lead Orientation:** The leads are spaced specifically for standard PCB grid patterns, making automated assembly easier. --- ### Common Applications * **Power Supplies:** Protecting the input or output stages of small AC/DC adapters. * **Consumer Electronics:** Used in televisions, monitors, and chargers. * **Industrial Controls:** Protecting PLCs and sensor interfaces. * **Telecommunications:** Shielding line cards and networking equipment from surges. --- ### Part Number Breakdown * **BK/**: Indicates bulk packaging. * **PCB**: The series name (Radial leaded circuit board fuse). * **3/4**: The amperage rating (0.75A). * **-R**: RoHS compliant (lead-free).