The **M2RS-3B-R** is a specific model of a **Miniature Rotary Switch**, commonly used in electronic circuits for manual selection of different modes, paths, or settings. Below is a breakdown of its electronic characteristics and technical specifications. --- ## 1. Component Overview The M2RS series is designed for PCB (Printed Circuit Board) mounting. The "3B" typically refers to the switching configuration, and "R" often denotes the handle type or RoHS compliance depending on the manufacturer (commonly associated with brands like **Copal Electronics** or **Nidec**). ### Key Specifications Table | Feature | Specification (Typical) | | :--- | :--- | | **Type** | Rotary Selector Switch | | **Mounting Type** | Through-hole PCB Mount | | **Number of Positions** | 2 to 3 (Binary/Manual selection) | | **Contact Rating** | 0.5A @ 125V AC / 0.2A @ 12V DC | | **Initial Contact Resistance** | 20 mΩ Max | | **Dielectric Strength** | 500V AC for 1 minute | | **Operating Temperature** | -25°C to +85°C | --- ## 2. Electronic Construction The part consists of three primary electronic sub-assemblies: 1. **Fixed Contacts:** These are the pins soldered into the PCB. They are usually silver or gold-plated to ensure low resistance and prevent oxidation. 2. **Wiper (Moving Contact):** A spring-loaded metal piece that rotates to bridge the connection between the common terminal and the selected output terminal. 3. **Detent Mechanism:** A physical notch system that provides "click" feedback to the user, ensuring the switch stays in a specific electronic state without drifting. --- ## 3. Circuit Configuration The "3B" designation usually implies a **Single Pole, 3-Position (1P3T)** or a specific binary coding. ### Pinout Logic Example When the dial is turned, the internal circuit changes as follows: | Position | Connected Pins | Result | | :--- | :--- | :--- | | **1** | Common + Pin A | Signal path 1 active | | **2** | Common + Pin B | Signal path 2 active | | **3** | Common + Pin C | Signal path 3 active | --- ## 4. Common Applications * **Mode Selection:** Choosing between different operating modes in industrial handheld devices. * **Voltage Regulation:** Manually switching between different resistor ladders to change output voltage. * **Audio Equipment:** Selecting input sources (Line In, Aux, Phono). * **Testing Equipment:** Changing the range or scale on a measurement tool. ---