The **3JS125-R** is a specific model of a **Miniature Cartridge Fuse** belonging to the 3JS series. It is widely used in electronic circuits to provide overcurrent protection. ### 1. Technical Specifications The "R" suffix typically denotes that the part is **RoHS compliant** (lead-free). Below are the primary electronic characteristics: | Property | Specification | | :--- | :--- | | **Fuse Type** | Miniature Cartridge (3AG / 6.3x32mm) | | **Current Rating** | 125mA (0.125A) | | **Voltage Rating** | 350V AC | | **Response Characteristic** | Slow Blow / Time Delay | | **Material** | Glass Body with Silver-Plated Brass Caps | | **Interrupting Rating** | 100A @ 350V AC | --- ### 2. Key Electronic Features * **Time-Delay (Slow Blow):** Unlike "Fast-Acting" fuses, the 3JS125-R is designed to withstand temporary surges or inrush currents. This prevents "nuisance blowing" when a device is first turned on. * **Physical Dimensions:** It follows the standard **1/4" x 1-1/4"** (6.3mm x 32mm) form factor, making it compatible with standard panel-mount or PCB-mount fuse holders. * **Glass Construction:** The transparent glass body allows for easy visual inspection to determine if the internal filament has melted. --- ### 3. Applications The 3JS125-R is commonly found in sensitive electronic equipment where low current protection is required but high initial startup voltages are present: 1. **Power Supplies:** Protecting the primary side of small transformers. 2. **Industrial Instrumentation:** Monitoring equipment that requires precise low-amperage protection. 3. **Consumer Electronics:** Older audio/video equipment and appliances. --- ### 4. Part Number Breakdown Understanding the nomenclature helps in sourcing replacements: | Prefix | Value | Suffix | | :--- | :--- | :--- | | **3JS** | Series ID (Slow Blow, Glass) | **125** | Current (125mA) | **-R** | RoHS Compliant | ---