The **M2AC-AC5-R/Q** is a specific model within the **M2 Series** of signal conditioners manufactured by **M-System**. This device is a high-performance AC current transducer designed to convert an alternating current (AC) input into a standard DC output signal. --- ### 1. Model Breakdown (Part Number Analysis) Understanding the suffix codes helps identify the specific electronic characteristics of this unit: | Code | Component Segment | Specification | | :--- | :--- | :--- | | **M2AC** | Base Model | AC Current Transducer (Average sensing) | | **AC5** | Input Range | 0 – 5A AC | | **R** | Output Signal | 4 – 20mA DC (Current Output) | | **Q** | Power Input | 100 – 240V AC | --- ### 2. Key Electronic Specifications The internal circuitry is designed for industrial-grade isolation and signal processing: * **Sensing Method:** Average sensing, RMS calibrated. This means it calculates the average value of the AC wave and scales it to represent the RMS value (ideal for pure sine waves). * **Isolation Structure:** 3-way isolation. The **Input**, **Output**, and **Power** terminals are electrically isolated from each other. * **Isolation Resistance:** $\ge$ 100 M$\Omega$ with 500V DC. * **Dielectric Strength:** 2000V AC @ 1 minute (Input to output to power to ground). * **Response Time:** $\le$ 0.5 seconds (0 – 90%). * **Overload Capacity:** 10 times the rated current for 3 seconds; 2 times continuously. --- ### 3. Wiring and Terminals The unit typically uses a M3.5 screw terminal base. Below is a general representation of the electronic connections: | Terminal No. | Function | Description | | :--- | :--- | :--- | | **1** | Input (U) | AC Current Input (0-5A) | | **2** | Input (V) | AC Current Input (0-5A) | | **4** | Output (+) | 4-20mA DC Positive | | **5** | Output (-) | 4-20mA DC Negative | | **7** | Power (L) | 100-240V AC Line | | **8** | Power (N) | 100-240V AC Neutral | --- ### 4. Application Logic The electronic internal logic follows this signal flow: 1. **Input Stage:** A small internal current transformer (CT) steps down the 0-5A AC signal. 2. **Rectification/Filtering:** The signal is rectified and smoothed to determine the average AC amplitude. 3. **Amplification:** An operational amplifier scales the signal to the calibrated range. 4. **Output Stage:** A voltage-to-current converter drives the 4-20mA loop, ensuring the signal remains constant despite fluctuations in load resistance (up to 750 $\Omega$). ---