The **7108K2CWCKE** is a specific part number for a sub-miniature toggle switch manufactured by **C&K** (now part of Littelfuse). This component is designed for high-reliability applications where environmental protection and specific switching logic are required. Below is a detailed breakdown of its specifications and electronic characteristics. --- ### 1. Part Number Breakdown To understand the electronic capabilities of this part, we can decode the nomenclature: | Code Segment | Feature | Description | | :--- | :--- | :--- | | **7108** | Model Series | SPDT (Single Pole Double Throw) Toggle Switch | | **K2** | Actuator | Locking Lever (provides security against accidental switching) | | **CW** | Bushing | Weatherproof / Splashproof (Internal O-ring seal) | | **C** | Terminations | PC Pin (Through-hole mounting) | | **K** | Contact Material | Gold over Nickel over Tin (Low power/Logic level) | | **E** | Seal | Epoxy sealed base (Prevents contamination during soldering) | --- ### 2. Electrical Specifications The "K" contact material indicates this is primarily a **logic-level** switch, meaning it is intended for low-voltage, low-current signals rather than high-power AC loads. | Parameter | Specification | | :--- | :--- | | **Contact Rating** | 0.4 VA max @ 20 V AC or DC | | **Switch Function** | On-None-Mom (Momentary) - *Spring return to center* | | **Contact Resistance** | 10 mΩ max (Initial) | | **Insulation Resistance** | $10^9$ Ω min | | **Dielectric Strength** | 1,000 Vrms @ sea level | | **Operating Temp** | -30°C to +85°C | --- ### 3. Key Electronic Features #### A. Momentary Action (On-None-Mom) Unlike a standard "On-Off" switch, the **7108** series designation indicates a specific switching logic. The toggle is normally in one position and must be held in the other position manually. Once released, it springs back to its original state. #### B. Gold Contacts The use of gold (K rating) is critical for electronics where the signal current is too low to "burn off" oxidation. Gold remains conductive even in low-use scenarios, ensuring signal integrity for microprocessors or sensors. #### C. Environmental Sealing (CW/E) The "CW" bushing includes an internal O-ring, and the "E" represents an epoxy base seal. These prevent flux, cleaning solvents, or moisture from entering the internal mechanism, making it suitable for harsh industrial or outdoor environments. #### D. Locking Lever (K2) The actuator is a "locking" type. This means the user must physically pull the lever up before it can be moved, preventing accidental activation in critical systems (e.g., aerospace or medical equipment). --- ### 4. Typical Applications * **Industrial Controls:** Emergency overrides or reset triggers. * **Medical Equipment:** Logic switching for diagnostic tools. * **Telecommunications:** Network hardware reset or configuration. * **Instrumentation:** Secure mode switching for calibration.