The **SL15-M2KT-R** is a high-performance **Current Limiting Negative Temperature Coefficient (NTC) Thermistor** manufactured by **AMETHERM**. It is primarily designed to suppress high inrush currents in power supplies and motor controllers. --- ## 1. Technical Specifications The following table summarizes the key electronic characteristics of the SL15-M2KT-R: | Parameter | Specification | Unit | | :--- | :--- | :--- | | **Resistance at 25°C ($R_{25}$)** | 15.0 | $\Omega$ | | **Max Steady State Current ($I_{max}$)** | 2.0 | Amperes | | **Resistance at Max Current** | 0.380 | $\Omega$ | | **Max Capacitance @ 120VAC** | 1000 | $\mu$F | | **Max Capacitance @ 240VAC** | 250 | $\mu$F | | **Dissipation Constant** | 15.0 | mW/°C | | **Thermal Time Constant** | 45 | Seconds | --- ## 2. Key Electronic Functions The SL15-M2KT-R operates based on the thermal properties of semiconductor materials: ### Inrush Current Limitation When a device is first powered on, capacitors act as short circuits, drawing a massive spike of current. Because the NTC has a resistance of **15 $\Omega$** at room temperature, it acts as a "buffer" to limit this initial spike, protecting fuses and diodes. ### Self-Heating Transition As current flows through the device, it generates heat. Because it is an NTC (Negative Temperature Coefficient) thermistor, its **resistance drops** as its temperature increases. At its maximum steady state, the resistance drops to approximately **0.38 $\Omega$**, minimizing power loss during normal operation. --- ## 3. Physical & Design Attributes * **Package Type:** Radial leaded (through-hole). * **Disc Diameter:** Approximately 15mm. * **Coating:** High-temperature silicone or phenolic resin for electrical insulation. * **Durability:** Designed to withstand repeated thermal cycling. --- ## 4. Common Applications 1. **Switch Mode Power Supplies (SMPS):** Limiting charging current for bulk capacitors. 2. **AC Motors:** Reducing starting torque and current spikes to prevent tripping breakers. 3. **LED Drivers:** Protecting sensitive internal circuitry from grid surges. 4. **Transformers:** Preventing magnetic inrush current from saturating the core. ---