The **KRTBS-321-R** is a specific electronic component, most commonly identified as a **tactile switch** (or tact switch). These are momentary push-button switches used in low-power circuits to provide physical feedback to the user. Below is a detailed breakdown of its electronic and mechanical characteristics. --- ### 1. General Specifications Tactile switches like the KRTBS-321-R are designed for Surface Mount Technology (SMT) and are typically found in consumer electronics. | Feature | Specification (Typical) | | :--- | :--- | | **Type** | Tactile Switch (Momentary) | | **Mounting Type** | Surface Mount (SMD/SMT) | | **Circuit** | SPST - NO (Single Pole Single Throw - Normally Open) | | **Actuation Force** | Usually 160gf to 250gf (grams-force) | | **Contact Rating** | 50mA @ 12V DC | | **Travel** | 0.25mm ± 0.1mm | --- ### 2. Key Internal Components The functionality of the KRTBS-321-R relies on several precision-engineered parts: * **Actuator (Button):** The top part that the user presses. It translates the external force to the internal dome. * **Contact Dome:** A metal "snap" disc. When pressed, it collapses to bridge two contacts, completing the circuit. It provides the "click" sound and tactile feel. * **Terminals:** Metal leads that are soldered to the PCB. These are usually plated with silver or gold to ensure high conductivity and prevent oxidation. * **Base/Housing:** Usually made of heat-resistant plastic (like LCP) to withstand the high temperatures of reflow soldering. --- ### 3. Applications Due to its small footprint and reliability, this component is used in: 1. **Consumer Electronics:** Volume buttons on smartphones, power buttons on cameras. 2. **Peripherals:** Computer mice, keyboards, and printers. 3. **Industrial:** Control panels and reset buttons on embedded systems. --- ### 4. Typical Footprint (SMD Layout) ```cpp // Schematic Symbol Representation // (1) ---[ \ ]--- (2) // Normally Open: Circuit closes only when pressed. ``` ---