The **RTS-12B-R** is a specific model of a **Rotary DIP Switch** manufactured by companies like **Copal Electronics (Nidec)**. These components are used to set binary or hexadecimal values manually on a circuit board, typically for addressing, configuration, or mode selection. --- ## 1. Technical Specifications The "RTS-12B-R" designation usually breaks down into specific electrical and mechanical characteristics: | Feature | Specification | | :--- | :--- | | **Switch Type** | Rotary DIP Switch | | **Number of Positions** | 10 (Decimal) or 16 (Hexadecimal) - *Variant dependent* | | **Output Code** | Real Binary Code (or BCD) | | **Actuator Style** | Recessed / Screwdriver slot | | **Mounting Type** | Through-hole (PCB) | | **Contact Rating** | 100mA @ 5V DC (Switching), 100mA @ 50V DC (Non-switching) | | **Contact Resistance** | 100 mΩ maximum | --- ## 2. Key Electronic Components & Materials The internal construction of the RTS-12B-R involves several critical materials to ensure long-term reliability: * **Contacts:** Usually plated with **Gold (Au)** over Nickel. Gold is used because it prevents oxidation, ensuring a stable connection even after years of inactivity. * **Housing:** Made of high-temperature resistant plastic (such as PPS or PBT), allowing the part to withstand wave soldering temperatures. * **Rotor:** The internal dial that rotates to bridge specific electrical paths to the output pins. * **O-ring Seal:** The "-R" suffix often indicates a "RoHS compliant" or "Resin-sealed" version. A sealed construction allows the part to be washed (aqueous cleaning) after soldering without damaging the internal contacts. --- ## 3. Terminal Layout & Logic The switch functions as a mechanical encoder. It has one **Common (C)** pin and several output pins (1, 2, 4, 8). ### Binary Coded Decimal (BCD) Truth Table When the dial is turned, it creates a physical short between the Common pin and the output pins according to the position: | Position | Pin 1 | Pin 2 | Pin 4 | Pin 8 | | :--- | :--- | :--- | :--- | :--- | | **0** | Open | Open | Open | Open | | **1** | **Closed** | Open | Open | Open | | **3** | **Closed** | **Closed** | Open | Open | | **8** | Open | Open | Open | **Closed** | --- ## 4. Common Applications * **Industrial Controls:** Setting Modbus or CAN bus node IDs. * **Telecommunications:** Configuring hardware presets. * **Home Automation:** Setting unique addresses for wireless sensors or light switches. * **Testing Equipment:** Manually toggling logic states during prototyping.