### Part Analysis: A103K1CWCQ0Q The **A103K1CWCQ0Q** is a specific part number for a **Subminiature Toggle Switch** manufactured by **C&K** (now part of Littelfuse). These switches are widely used in instrumentation, telecommunications, and medical equipment due to their reliability and compact size. --- ### 1. Part Number Breakdown The alphanumeric code follows C&K's naming convention, defining every physical and electrical characteristic: | Segment | Code | Description | | :--- | :--- | :--- | | **Series** | **A** | A Series: Subminiature Toggle Switches | | **Function** | **103** | SPDT (Single Pole Double Throw), On-Off-On function | | **Actuator** | **K1** | Locking Lever (Safety feature: must be pulled to move) | | **Bushing** | **CW** | 0.250" high, keyway, threaded, splashproof (O-ring seal) | | **Termination** | **C** | PC Thru-hole (Printed Circuit) | | **Contact Material** | **W** | Gold over silver (Commonly used for logic/power flexibility) | | **Seal** | **Q** | Epoxy sealed terminals (Prevents flux contamination) | | **RoHS/Lead** | **0Q** | RoHS compliant / Standard Lead-free finish | --- ### 2. Key Technical Specifications Below are the typical electrical and mechanical limits for the A-Series "Q" contact rating: * **Contact Rating:** * 5 Amps @ 120 V AC or 28 V DC. * 2 Amps @ 250 V AC. * **Electrical Life:** 40,000 make-and-break cycles at full load. * **Contact Resistance:** Below 10 mΩ (initial). * **Insulation Resistance:** 10⁹ Ω minimum. * **Dielectric Strength:** 1,000 Vrms @ sea level. * **Operating Temperature:** -30°C to +85°C. --- ### 3. Design Features #### **Locking Lever (K1 Actuator)** One of the most distinct features of this specific model is the **Locking Lever**. To move the switch from one position to another, the operator must physically pull the lever upward. This prevents accidental switching in high-vibration environments or critical control panels. #### **Environmental Protection (CW Bushing)** The "CW" designation indicates a **Splashproof** design. It includes an internal O-ring seal that prevents moisture or contaminants from entering the switch body through the bushing. #### **Gold over Silver Contacts (W Material)** This provides a "best of both worlds" scenario: * **Gold layer:** Ensures reliable switching at low-current (Logic level) by preventing oxidation. * **Silver base:** Allows for higher power handling (up to 5A) once the gold layer wears during high-power use. --- ### 4. Typical Applications * **Industrial Controls:** Emergency overrides or mode selectors. * **Medical Equipment:** Critical power or mode settings. * **Avionics:** Control panels where accidental toggling could be dangerous. * **Telecommunications:** Base station hardware resets.