The **CD08RM0AB-R** is a specific model of a **Rotary DIP Switch** manufactured by C&K (now part of Littelfuse). These components are commonly used on printed circuit boards (PCBs) to set binary-coded configurations manually. --- ## 1. Core Technical Specifications The model number encodes specific features of the switch. Here is the breakdown of its technical characteristics: | Feature | Specification | | :--- | :--- | | **Switch Type** | Rotary DIP Switch | | **Output Code** | Binary Coded Decimal (BCD) | | **Number of Positions** | 8 Positions (0 through 7) | | **Actuator Style** | Flush (requires a screwdriver or tool to turn) | | **Mounting Type** | Through-Hole, Right Angle | | **Contact Rating** | 0.4 VA @ 20V AC/DC (Logic Level) | | **Operating Temp** | -25°C to 85°C | | **Termination** | PC Pins (Gold plated contacts) | --- ## 2. Pin Configuration and Logic As a BCD (Binary Coded Decimal) switch with 8 positions, it translates the physical rotation of the dial into a 3-bit binary output across its output pins. ### Logic Truth Table (8-Position) | Position | Pin 1 (1) | Pin 2 (2) | Pin 3 (4) | Common | | :--- | :--- | :--- | :--- | :--- | | **0** | Open | Open | Open | Closed | | **1** | Closed | Open | Open | Closed | | **2** | Open | Closed | Open | Closed | | **3** | Closed | Closed | Open | Closed | | **4** | Open | Open | Closed | Closed | | ... | ... | ... | ... | ... | | **7** | Closed | Closed | Closed | Closed | --- ## 3. Key Electronic Features ### A. Right Angle Orientation The **"AB"** in the part number signifies the **Right Angle** mount. This allows the switch to be adjusted from the side of a PCB, which is ideal for devices where the top of the board is covered by a housing or another shield. ### B. Process Sealed The **"R"** suffix typically indicates that the part is supplied in **Tape & Reel** or is **Process Sealed**. This means the internal contacts are protected by an O-ring or seal, allowing the PCB to undergo automated wave soldering and cleaning (washing) without contaminating the contacts. ### C. Logic Level Switching Because the contacts are gold-plated and rated for **0.4 VA**, this switch is designed for **signal-level switching** only. It should be connected to high-impedance inputs (like a microcontroller's GPIO) and not used to switch power loads directly. --- ## 4. Common Applications * **Address Setting:** Assigning a unique ID to a device on a bus (e.g., RS-485 or DMX networks). * **Mode Selection:** Selecting between different operating firmware modes without needing a screen or interface. * **Industrial Controls:** Setting timers, limits, or configuration parameters on PLC modules.