The **M2VT-B1-R/K** is a high-performance **Mini-M series signal conditioner** manufactured by M-System (now MG CO., LTD.). It is specifically designed to convert a variable resistance input (such as a potentiometer) into a standard DC output signal. ### 1. Key Technical Specifications The model code **M2VT-B1-R/K** can be broken down into the following electronic characteristics: | Component Code | Description | Details | | :--- | :--- | :--- | | **M2VT** | Model Series | Potentiometer Transmitter (Mini-M Series) | | **B** | Input Type | Potentiometer (100 $\Omega$ to 10 k$\Omega$) | | **1** | Output Type | 4 – 20 mA DC (Load resistance max. 750 $\Omega$) | | **R** | Power Input | 24V DC | | **K** | Options | Multi-wire connection / High-accuracy spec | --- ### 2. Functional Electronic Components Internally, the M2VT-B1-R/K consists of several critical electronic stages: #### A. Input Circuit (Potentiometer Interface) * **Constant Voltage Source:** The device provides a stable reference voltage to the potentiometer. * **Buffer Amplifier:** A high-impedance stage that senses the position of the wiper without loading the circuit, ensuring linearity. #### B. Isolation Barrier * **Three-Way Isolation:** This part uses opto-isolators or magnetic transformers to separate the **Input**, **Output**, and **Power** circuits. * **Purpose:** Prevents ground loops, protects sensitive PLC/DCS inputs from high-voltage surges, and reduces electrical noise. #### C. Signal Conditioning & Scaling * **Zero/Span Adjustment:** Located on the front panel, these potentiometers allow the user to calibrate the 0% and 100% points. * **Linearization:** The internal circuitry ensures that the mechanical rotation of the potentiometer is translated into a linear current output. #### D. Output Stage * **Current Driver:** Converts the conditioned voltage signal into a regulated 4-20mA current loop. * **Protection:** Includes overcurrent protection and polarity reversal protection for the 24V DC power input. --- ### 3. Connection Diagram (General) To operate the device, the following electronic connections are typically required: | Terminal | Function | Connection | | :--- | :--- | :--- | | **1 & 2** | Output (+) / (-) | To PLC/Controller (4-20mA) | | **3 & 4** | Power (+) / (-) | 24V DC Supply | | **5, 6, 7** | Input | To Potentiometer (End, Wiper, End) | --- ### 4. Environmental & Physical Specs * **Construction:** Plug-in base socket for easy maintenance. * **Housing:** Flame-resistant black resin. * **Isolation Resistance:** $\ge$ 100 M$\Omega$ with 500V DC. * **Dielectric Strength:** 2000V AC @ 1 minute (Input to output to power to ground).