## M2RS-10-R2: Electronic Overview The **M2RS-10-R2** is a specific model within the **M2RS series of Rotary Switches**, commonly manufactured by Copal Electronics (Nidec). These are sub-miniature, surface-mount (SMT) rotary code switches used to set configurations on printed circuit boards (PCBs). --- ### 1. Key Specifications | Feature | Specification | | :--- | :--- | | **Code Type** | Real Code (Decimal) | | **Number of Positions** | 10 (0 to 9) | | **Mounting Type** | Surface Mount (SMT), Right Angle | | **Actuator Type** | Rotor (Screwdriver slot) | | **Contact Rating** | 100mA @ 5V DC (Switching) / 100mA @ 50V DC (Non-switching) | | **Operating Temperature** | -40°C to +85°C | --- ### 2. Internal Electronic Design The M2RS-10-R2 functions as a **Binary Coded Decimal (BCD)** or **Decimal** selector. * **Terminal Configuration:** It typically features a **Common (C)** terminal and four output pins (1, 2, 4, 8). * **Switching Logic:** As the rotor is turned to a specific number (e.g., "3"), the internal mechanical wipers connect the Common terminal to the outputs that sum up to that value (e.g., pins 1 and 2). * **Wiping Contact:** The "R" in the series often signifies a high-reliability wiping contact mechanism, which helps remove oxidation from the contacts during rotation, ensuring low contact resistance over time. --- ### 3. Physical & Mechanical Attributes * **Form Factor:** It is designed for high-density mounting. The "R2" suffix specifically refers to the **Right Angle** orientation and the packaging (often Tape & Reel). * **Sealing:** These switches are usually **washable**. They feature an O-ring or a sealed construction that allows the PCB to be cleaned with solvents after soldering without damaging the internal contacts. * **Durability:** They are rated for approximately 10,000 steps (cycles). --- ### 4. Common Applications 1. **Address Setting:** Used in industrial networking (like RS-485 or CAN bus nodes) to manually set a unique ID for a device. 2. **Mode Selection:** Selecting operational modes in embedded systems (e.g., Test Mode vs. Run Mode). 3. **Configuration:** Setting baud rates or communication protocols on peripheral hardware. --- ### 5. Part Number Breakdown | Segment | Meaning | | :--- | :--- | | **M2** | Series Name (Sub-miniature Rotary) | | **RS** | Right Angle, SMT | | **10** | 10 Positions (0-9) | | **R2** | Packaging/Revision (Tape & Reel) | ---