The **MDL-2-R** is a specific model of electronic component belonging to the **MDL series** of fuses. It is a small-dimension, time-delay (slow-blow) glass tube fuse widely used in consumer electronics and industrial equipment. ### 1. Technical Specifications The part number "MDL-2-R" can be broken down to understand its core specifications: | Feature | Specification | Description | | :--- | :--- | :--- | | **Series** | MDL | Time-delay, glass tube series | | **Current Rating** | 2 Amperes | Maximum continuous current it can carry | | **Voltage Rating** | 250 VAC | Maximum operating voltage | | **Fuse Type** | Time-Delay | Also known as "Slow-Blow" | | **Dimensions** | 1/4" x 1-1/4" | Standard size (6.35mm x 31.75mm) | | **Material** | Glass Tube | Allows for visual inspection of the filament | | **Termination** | Ferrule | Nickel-plated brass end caps | | **RoHS Compliant** | Yes (indicated by "-R") | Lead-free and environmentally friendly | --- ### 2. Internal Mechanism and Function Unlike a "Fast-Acting" fuse that blows instantly upon exceeding the current limit, the MDL-2-R is designed with a specific thermal characteristic: * **Temporary Surges:** It can withstand brief high-current surges (inrush current) without blowing. This is essential for devices with motors or large capacitors that draw a lot of power for a split second when turned on. * **Sustained Overload:** If the current stays above 2A for a prolonged period, the internal element melts, breaking the circuit to prevent fire or component damage. --- ### 3. Key Electronic Characteristics The performance of the MDL-2-R is defined by its **I²t (Ampere-squared seconds)** value, which measures the thermal energy required to melt the fuse element. * **Interrupting Rating:** At 250VAC, it typically has an interrupting rating of 100A. At 125VAC, this rating increases significantly (up to 10,000A). * **Resistance:** It has a very low cold resistance (typically measured in milliohms) to ensure minimal voltage drop across the fuse during normal operation. --- ### 4. Common Applications The MDL-2-R is typically found in: * **Power Supplies:** Protecting the input stage from surges. * **Consumer Appliances:** Microwaves, chargers, and older television sets. * **Industrial Controls:** Small motors and solenoid valves where "start-up" current is higher than "running" current.