The **M2AC-AC4W-R** is a specific model within the **M2AC Series** of signal conditioners manufactured by **M-System**. This device is a compact, plug-in type signal transmitter designed to convert an alternating current (AC) input into a standard direct current (DC) output. --- ### 1. Key Technical Specifications The model number can be broken down into specific electronic parameters: | Component Code | Description | Specifications | | :--- | :--- | :--- | | **M2AC** | Series Name | AC Transmitter (Plug-in) | | **AC** | Input Signal | AC Current (e.g., from a CT) | | **4W** | Output Signal | 4 – 20 mA DC (Load resistance 550 $\Omega$ max.) | | **R** | Power Input | 24V DC (Allowable range: 24V $\pm$ 10%) | --- ### 2. Functional Electronic Design The device operates through four primary electronic stages to ensure signal integrity and safety: 1. **Input Conditioning:** It accepts AC current (typically 0–1A or 0–5A AC). It utilizes an internal transformer or shunt to sample the current. 2. **Rectification & Filtering:** The AC signal is converted to a proportional DC voltage. High-quality capacitors and filters are used to ensure the output is a "Mean Value Analysis" of the input sine wave. 3. **Isolation (3-Port):** This is a critical electronic feature. The device provides galvanic isolation between: * **Input** * **Output** * **Power Supply** * *Isolation Resistance:* $\ge$ 100 M$\Omega$ at 500V DC. 4. **Amplification/Conversion:** The signal is scaled to a linear 4–20 mA output, which is the industry standard for PLCs and SCADA systems. --- ### 3. Physical & Installation Features * **Construction:** Modular plug-in design. The electronic components are housed in a flame-resistant black resin case. * **Connection:** Uses an 8-pin circular socket for easy replacement without disconnecting wires. * **Adjustments:** Contains zero and span adjustments (trimmer potentiometers) on the front panel to calibrate the output signal. --- ### 4. Application Use Case This part is primarily used in **Power Monitoring**. For example, if a large industrial motor is drawing 0–5A AC, the M2AC-AC4W-R converts that fluctuating AC value into a steady 4–20mA DC signal that a control computer can understand.