The part number **209010** is most commonly associated with **Littelfuse**, a global leader in circuit protection. Specifically, it refers to a **5x20mm Time-Delay (Slo-Blo) Glass Body Cartridge Fuse**. --- ### 1. Technical Specifications This fuse is designed to protect electronic circuits from overcurrent conditions while allowing for temporary surges (like motor startups). | Parameter | Specification | | :--- | :--- | | **Manufacturer** | Littelfuse | | **Series** | 209 Series | | **Current Rating** | 10A (Amperes) | | **Voltage Rating** | 125V AC / 250V AC | | **Fuse Type** | Time-Delay / Slow-Blow | | **Body Material** | Glass | | **Dimensions** | 5mm x 20mm (Standard size) | | **Termination** | Cartridge (Ferrule) | --- ### 2. Key Features * **Time-Delay Characteristic:** Unlike "Fast-Acting" fuses, the 209010 is engineered to withstand high inrush currents for a short duration without blowing. * **Glass Body:** Allows for easy visual inspection to see if the internal filament has melted. * **Global Standards:** These fuses are typically UL and CSA recognized, making them suitable for consumer electronics and industrial machinery worldwide. --- ### 3. Common Applications Due to its 10A rating and slow-blow nature, this part is frequently found in: 1. **Power Supplies:** Protecting the input stage of desktop computers or servers. 2. **Home Appliances:** Used in microwaves, refrigerators, and high-end audio equipment. 3. **Industrial Equipment:** Protecting control circuits and small motors. 4. **LED Lighting Drivers:** Handling the initial power surge when lights are turned on. --- ### 4. Safety and Replacement > **Warning:** When replacing a 209010 fuse, always ensure the replacement has the same **Ampere (10A)** and **Voltage (250V)** rating. Never replace a "Slow-Blow" fuse with a "Fast-Acting" fuse, as it will likely blow immediately upon device startup.