The **CT01-020-R** is a high-precision, surface-mount (SMD) current transformer manufactured by **Coto Technology** (RedRock). It is specifically designed to provide non-intrusive current sensing in a compact form factor. --- ### ## Technical Specifications Below are the primary electronic characteristics of the CT01-020-R: | Parameter | Value / Specification | | :--- | :--- | | **Primary Current Range** | 0.1A to 20A | | **Turns Ratio** | 1:20 (Standard) | | **Secondary Resistance** | ~0.75 Ω | | **Frequency Range** | 50Hz to 1kHz | | **Isolation Voltage** | 2500 Vrms | | **Mounting Type** | Surface Mount Device (SMD) | | **Operating Temperature** | -40°C to +125°C | --- ### ## Core Electronic Components & Operation The functionality of the CT01-020-R relies on three main electronic principles: 1. **Toroidal Core:** The device uses a high-permeability magnetic core. The primary conductor (carrying the current to be measured) passes through the center, while the secondary winding is wrapped around the core. 2. **Electromagnetic Induction:** As AC current flows through the primary wire, it creates a magnetic field. This field induces a proportional current in the secondary winding based on the **1:20 turns ratio**. 3. **Burden Resistor Requirement:** To convert the induced secondary current into a measurable voltage (for an ADC or Microcontroller), an external **burden resistor** must be placed across the secondary terminals. --- ### ## Typical Application Circuit When integrating this part into a PCB design, the following configuration is standard: ```c // Simplified logic for calculating Output Voltage V_out = (I_primary / Turns_Ratio) * R_burden // Example: // I_primary = 10A // Turns_Ratio = 20 // R_burden = 10 Ohms // V_out = (10 / 20) * 10 = 5V AC ``` ### ## Key Features & Advantages * **High Isolation:** The 2500Vrms rating ensures that the sensitive monitoring electronics are physically and electrically isolated from high-voltage power lines. * **Compact Footprint:** Unlike traditional through-hole current transformers, the CT01-020-R is designed for automated SMT assembly, saving significant board space. * **Linearity:** It offers excellent linearity over its rated current range, making it suitable for power metering and over-current protection. ---