The **PEWCT1109** is a precision current transformer, specifically designed for mounting on Printed Circuit Boards (PCBs). These components are primarily used for sensing, monitoring, and measuring alternating current (AC) in electronic circuits. --- ### 1. Technical Specifications The following table summarizes the typical electronic characteristics of the PEWCT1109 series: | Parameter | Typical Value / Range | | :--- | :--- | | **Turns Ratio** | 1000:1 (Commonly) | | **Rated Input Current** | 0 - 20A | | **Max Input Current** | 50A - 60A | | **Frequency Range** | 50Hz - 400Hz | | **Dielectric Strength** | 2500V AC / 1 minute | | **Insulation Resistance** | 1000MΩ @ 500V DC | | **Operating Temperature** | -40°C to +85°C | --- ### 2. Core Components and Materials The electronic performance of the PEWCT1109 relies on three main internal parts: * **Magnetic Core:** Usually made of High-Permeability Nanocrystalline or Permalloy. This ensures high accuracy and minimal phase shift even at low currents. * **Secondary Winding:** Comprised of fine copper wire wound precisely around the core. The number of turns determines the transformation ratio. * **Encapsulation:** The internal parts are potted with epoxy resin inside a flame-retardant plastic casing (UL94-V0 rated) to provide moisture resistance and electrical insulation. --- ### 3. Application Circuit To convert the output current into a readable voltage for a Microcontroller (MCU) or ADC, a **Burden Resistor ($R_b$)** must be used. **Basic Calculation:** $V_{out} = (\frac{I_{primary}}{Turns Ratio}) \times R_b$ ```cpp // Example: Calculating Current in C++ float getACCurrent(float voltageRead, int turnsRatio, float burdenResistor) { float secondaryCurrent = voltageRead / burdenResistor; return secondaryCurrent * turnsRatio; // Returns Primary Current } ``` --- ### 4. Key Advantages 1. **Galvanic Isolation:** Physically separates the high-power AC line from the low-power control electronics. 2. **Linearity:** Provides a very linear output relative to the input current across its rated range. 3. **Compact Form Factor:** The "Pin-thru-hole" design allows for easy integration into power meters and smart plugs.