The **MDL-1/2-R** is a specific model of electronic fuse manufactured by Eaton (formerly Bussmann). It is a standard glass tube fuse used widely in power supplies, consumer electronics, and industrial equipment. --- ### 1. Technical Specifications The part number can be decoded to understand its electrical characteristics: | Parameter | Value / Description | | :--- | :--- | | **Series** | MDL (Standard 1/4" x 1-1/4" glass tube) | | **Current Rating** | 0.5 Amps (1/2 Amp) | | **Voltage Rating** | 250 VAC | | **Response Characteristic** | Time-Delay (Slow-Blow) | | **Material** | Glass Tube with Nickel-plated Brass Endcaps | | **RoHS Compliant** | Yes (Indicated by the **-R** suffix) | --- ### 2. Key Features * **Time-Delay Function:** Unlike "Fast-Acting" fuses, the MDL-1/2-R is designed to withstand temporary surges or "inrush currents." It will not blow immediately if the current slightly exceeds 0.5A for a fraction of a second, which is common when motors or large capacitors start up. * **Physical Dimensions:** It follows the standard physical size of **6.3mm x 32mm** (1/4" x 1-1/4"). * **Interrupting Rating:** At 250VAC, it typically has an interrupting rating of 35A; at 125VAC, it can handle up to 10,000A. --- ### 3. Comparison: MDL vs. AGC It is common to confuse MDL fuses with AGC fuses. Here is the primary difference: | Feature | MDL Series | AGC Series | | :--- | :--- | :--- | | **Response Type** | **Time-Delay** (Slow) | **Fast-Acting** (Quick) | | **Internal Filament** | Usually a coiled wire or thick element | Usually a straight, thin wire | | **Application** | Inductive loads (Motors, Transformers) | Resistive loads (Light bulbs, simple circuits) | --- ### 4. Circuit Symbol and Implementation In a schematic, the MDL-1/2-R is represented by a standard fuse symbol. It is typically placed on the "Hot" or "Live" side of the AC input. ```mermaid graph LR A[AC Power In] --> B{Fuse MDL-1/2-R} B --> C[Transformer / Load] C --> D[Neutral] ``` --- ### 5. Common Applications * **Control Transformers:** Protecting the primary or secondary windings. * **Audio Equipment:** Protecting internal power rails. * **Industrial Solenoids:** Managing the high initial current required to move the plunger.