The **FNS-C2-R** is an electronic component, specifically a **Surface Mount Device (SMD) Tactile Switch** manufactured by companies like **Fujisoku** (a brand under Nidec Components). It is widely used in control panels, instrumentation, and consumer electronics. --- ## 1. Technical Specifications The FNS-C2-R is characterized by its compact footprint and specific tactile feedback. Below are the primary electronic and mechanical specifications: | Parameter | Specification | |:---|:---| | **Switch Type** | Tactile / Momentary Pushbutton | | **Mounting Type** | Surface Mount (SMD / SMT) | | **Circuit Configuration** | SPST (Single Pole, Single Throw) | | **Switch Function** | OFF - (ON) | | **Contact Rating** | 50mA @ 12V DC | | **Contact Resistance** | 100 mΩ max | | **Operating Force** | ~1.57 N (160gf) | | **Travel** | 0.25 mm | | **Operating Temperature** | -25°C to +70°C | --- ## 2. Structural & Material Breakdown The device consists of four main electronic/mechanical parts: ### A. Contact Dome * **Material:** Usually stainless steel or phosphor bronze with silver plating. * **Function:** This is the "heart" of the switch. It provides the tactile "click" feel and completes the electrical circuit when pressed. ### B. Actuator (Stem) * **Material:** High-temperature thermoplastic (e.g., LCP or Nylon). * **Function:** The physical button that the user presses. In the "R" variant, this is often a standard height plunger. ### C. Terminals (Leads) * **Material:** Copper alloy with silver or gold plating. * **Design:** These are "Gull-wing" style leads for surface mounting, ensuring a strong solder bond to the PCB. ### D. Base and Cover * **Function:** The base holds the contacts, while the metal cover (often stainless steel) is crimped over the assembly to protect against dust and mechanical stress. --- ## 3. Terminal Layout The switch typically features 4 pins, though it is a Single Pole device. The pins are internally connected in pairs to provide mechanical stability on the PCB. ```text Pin 1 -----+----- Pin 2 | [Switch] | Pin 3 -----+----- Pin 4 ``` * *Note: Pressing the button connects Pin 1/2 to Pin 3/4.* --- ## 4. Common Applications * **Consumer Electronics:** Reset buttons, mode selectors. * **Industrial:** Logic input triggers for Microcontrollers (MCUs). * **Medical:** Interface buttons for portable diagnostic tools.