The **RJS3-R** is a specific model of a **subminiature radial lead fuse** manufactured by Bel Fuse Inc. It is widely used in power supplies, chargers, and consumer electronics due to its compact form factor and reliability. --- ## 1. Component Overview The RJS3-R belongs to the "RJS" series of fuses. The suffix "-R" typically denotes compliance with RoHS (Restriction of Hazardous Substances) standards. ### Technical Specifications | Feature | Specification | | :--- | :--- | | **Type** | Subminiature Radial Lead Fuse | | **Current Rating** | 3 Amperes | | **Voltage Rating** | 600V AC | | **Interrupting Rating** | 60A @ 600V AC | | **Response Time** | Fast Acting / Quick Acting | | **Body Material** | Glass Tube with Brass Caps | | **Mounting Type** | Through-hole (Radial Leads) | --- ## 2. Key Physical Features * **Radial Leads:** Unlike traditional cylindrical fuses that fit into clips, this fuse has two wires (leads) extending from one side, allowing it to be soldered directly onto a Printed Circuit Board (PCB). * **Space Saving:** Its vertical orientation (standing up on the board) saves significant "real estate" compared to horizontal fuse holders. * **Pigtail Design:** Often referred to as a "pigtail" fuse, the leads are pre-attached to the end caps. --- ## 3. Electrical Characteristics The RJS3-R is designed for **primary circuit protection**. 1. **Fast-Acting:** It is engineered to blow almost instantly when the current exceeds 3A. This protects sensitive downstream components from sudden surges. 2. **High Voltage Rating:** With a 600V AC rating, it is suitable for industrial power applications and high-voltage power supplies where lower-rated fuses (like 125V or 250V) would be unsafe. 3. **Breaking Capacity:** It can safely interrupt a fault current of up to 60 Amps at its rated voltage without the glass tube shattering. --- ## 4. Common Applications * **Power Supplies:** Used in AC/DC adapters and switching power supplies. * **Battery Chargers:** Protecting the charging circuit from overcurrent. * **Monitors/TVs:** Guarding the internal power board. * **Telecom Equipment:** High-voltage protection for networking hardware. --- ## 5. Part Number Breakdown While codes can vary slightly by manufacturer, the Bel Fuse nomenclature generally follows: * **RJS:** Series Name (Radial, Glass Body). * **3:** Ampere Rating (3A). * **-R:** RoHS Compliant (Lead-free).