The **KFS-3C-R** is a specific model of a **Full-Size Mechanical Key Switch** manufactured by **Kailh (Kaihua Electronics)**. It is part of their standard mechanical switch lineup, commonly found in industrial control panels, specialized keyboards, and gaming peripherals. ### 1. Technical Specifications The following table highlights the core electronic and mechanical parameters of the KFS-3C-R: | Parameter | Specification | | :--- | :--- | | **Switch Type** | Mechanical (Tactile/Clicky variant typically) | | **Contact Material** | Gold Alloy (for corrosion resistance) | | **Operating Force** | 50 ± 15 gf | | **Total Travel** | 4.0 ± 0.4 mm | | **Pre-travel** | 2.0 ± 0.6 mm | | **Electrical Life** | 50,000,000 Cycles | | **Voltage Rating** | 12V AC/DC Max | | **Current Rating** | 10mA Max | --- ### 2. Internal Electronic Components The "electronics" of this part are relatively simple but precision-engineered for durability: 1. **The Stationary Blade:** A copper alloy plate that stays fixed within the housing. It is connected to one of the pins protruding from the bottom. 2. **The Movable Blade (Leaf Spring):** A flexible metal piece that reacts to the plunger's movement. When the key is pressed, it makes physical contact with the stationary blade to close the circuit. 3. **Gold Cross-Point Contacts:** To ensure reliable electrical conduction even at low voltages (where oxidation can be an issue), the contact points are usually plated with gold. 4. **Terminals:** Two metal pins at the base designed for Through-Hole Technology (THT) mounting on a PCB. --- ### 3. Part Number Decoding The suffix **"-R"** in Kailh's nomenclature often refers to specific design variations: * **Color/Feel:** In many Kailh series, "R" can denote a specific stem color (often Red, implying a linear feel), but in the KFS industrial series, it often refers to the **Retention** or **Reset** mechanism type. * **Mounting:** It is a 3-pin design (2 electrical pins + 1 center guide post), making it compatible with most standard mechanical keyboard PCBs. --- ### 4. Application Use Cases Due to its high cycle life (50 million actuations), the KFS-3C-R is used in: * **POS Terminals:** Cash registers and credit card machines. * **Industrial Controllers:** CNC machine interfaces. * **Custom Keypads:** Security systems and specialized data entry tools. ---