The **KFS-04-R/Q** is a specific series of **Rotary DIP Switches** manufactured by companies like Kingfont or similar electronic component vendors. These are used primarily on Printed Circuit Boards (PCBs) to manually set digital configurations. --- ### 1. Technical Specifications The "04" typically indicates the number of positions or the encoding type, while "R/Q" refers to the terminal shape and mounting orientation. | Feature | Specification | | :--- | :--- | | **Switch Type** | Rotary DIP Switch | | **Positions** | 4, 10, or 16 (Model dependent, usually BCD or Hexadecimal) | | **Actuator Type** | Flat or Arrow (Screwdriver adjustable) | | **Mounting Type** | Through-Hole (THT) or Surface Mount (SMT) | | **Current Rating** | Switching: 25mA, 24VDC / Non-switching: 100mA, 50VDC | | **Contact Resistance** | 100mΩ Max | | **Operating Temp** | -25°C to +70°C | --- ### 2. Physical Construction The device consists of several critical electronic and mechanical parts: 1. **The Rotor (Actuator):** The top part that turns. It usually has a slot for a flat-head screwdriver. The position of the arrow determines which pins are connected. 2. **Contact Plate:** Internally, a gold-plated or silver-plated copper alloy disc rotates against fixed terminals. 3. **Housing:** Made of high-temperature liquid crystal polymer (LCP) or PBT plastic to withstand soldering heat. 4. **Terminals:** The metal pins extending from the base. * **R-Type:** Usually refers to right-angle or specific pin spacing. * **Q-Type:** Often denotes a "Gull-wing" or "J-hook" SMT lead style. --- ### 3. Truth Table (Logic Output) For a standard 4-position or BCD rotary switch, the electronic behavior follows binary logic. When you turn the dial, it shorts the "Common" (C) pin to specific output pins (1, 2, 4, 8). | Position | Pin 1 (2⁰) | Pin 2 (2¹) | Pin 4 (2²) | Pin 8 (2³) | | :--- | :--- | :--- | :--- | :--- | | **0** | OFF | OFF | OFF | OFF | | **1** | ON | OFF | OFF | OFF | | **2** | OFF | ON | OFF | OFF | | **3** | ON | ON | OFF | OFF | --- ### 4. Common Applications * **Address Setting:** Used in industrial RS-485 or CAN bus devices to set a unique ID. * **Mode Selection:** Choosing between different firmware modes in embedded systems. * **Configuration:** Adjusting hardware parameters without needing a digital interface or screen.