Based on the product code **SWT8-R**, this typically refers to a **Surface Mount (SMD) Tactile Switch**, often associated with manufacturers like Diptronics or similar electronic component suppliers. The "SWT8" series generally indicates the physical footprint (6x6mm or similar, depending on the datasheet), and the "R" often signifies **Tape & Reel** packaging or a specific **Right-Angle** orientation. --- ## 1. Technical Specifications (Typical) Below are the common electrical and mechanical characteristics for the SWT8-R series: | Parameter | Specification | | :--- | :--- | | **Switch Type** | Tactile (Momentary) | | **Contact Rating** | 50mA, 12V DC | | **Insulation Resistance** | 100MΩ Min at 100V DC | | **Dielectric Strength** | 250V AC for 1 minute | | **Contact Resistance** | 100mΩ Max | | **Operating Force** | 100gf, 160gf, or 260gf (Model dependent) | | **Operating Life** | 50,000 to 100,000 cycles | | **Travel** | 0.25mm ± 0.1mm | --- ## 2. Component Structure The SWT8-R consists of several key electronic and mechanical layers: 1. **Cover:** Usually stainless steel or nickel-plated brass to protect the internal dome. 2. **Actuator (Stem):** The button part you press. Materials vary (Silicon or Plastic) and heights can be customized (e.g., 4.3mm, 5.0mm). 3. **Contact Dome:** A metal "snap" disc (usually stainless steel with silver plating). This provides the tactile feedback and completes the circuit. 4. **Base:** A high-temperature thermoplastic (LCP or Nylon) capable of withstanding reflow soldering. 5. **Terminals:** Silver-plated brass or copper alloy pins for electrical connection to the PCB. --- ## 3. Circuit Diagram Tactile switches like the SWT8-R are generally **SPST (Single Pole Single Throw)**, meaning they are "Normally Open." ```text Pin 1 o-------+-------o Pin 2 | [Switch] | Pin 3 o-------+-------o Pin 4 ``` *Note: In most 4-pin 6x6mm tactile switches, Pins 1 & 2 are internally connected, and Pins 3 & 4 are internally connected.* --- ## 4. Part Numbering Breakdown (Example) While specific to the manufacturer, the code usually breaks down as follows: * **SWT:** Switch Type (Tactile). * **8:** Series/Size designator. * **R:** Packaging (Tape & Reel) **OR** Orientation (Right-Angle). *Always check the specific datasheet to confirm if the 'R' denotes the physical bend of the pins or the shipping method.* ---