The **311HS** series typically refers to high-reliability, subminiature snap-action switches manufactured by Honeywell (Micro Switch). These are widely used in aerospace, military, and industrial applications due to their compact size and environmental resilience. --- ## 1. Key Technical Specifications Below are the typical technical parameters for the 311HS series: | Feature | Specification | | :--- | :--- | | **Switch Type** | Subminiature Snap Action | | **Circuitry** | SPDT (Single Pole Double Throw) | | **Actuator Style** | Integral Lever (Various lengths/shapes) | | **Current Rating** | 1A to 5A (Depending on voltage) | | **Voltage Rating** | 125 VAC / 28 VDC | | **Operating Force** | 0.22 N to 1.47 N | | **Termination** | Solder or Turret terminals | --- ## 2. Structural Components The 311HS is engineered for precision. Its internal electronic and mechanical parts include: ### A. Contact Mechanism * **Gold or Silver Contacts:** Depending on the specific model, contacts are plated to ensure low electrical resistance. Gold is used for low-energy "dry" circuits to prevent oxidation. * **Snap-Action Spring:** A beryllium copper spring ensures a rapid "snap" transition, which minimizes arcing and extends the life of the switch. ### B. Actuators (Levers) The "311" designation often implies the inclusion of an **integral lever**. Unlike the 11HS series (which is basic pin plunger), the 311HS features: * Straight levers. * Simulated roller levers. * Roller levers. ### C. Housing materials * **Phenolic/Diallyl Phthalate:** The case is made from high-grade thermoset plastics that offer excellent electrical insulation and heat resistance. * **Hermetic Sealing (HS Series):** The "HS" suffix stands for **Hermetically Sealed**. These switches are often vapor-sealed to protect internal contacts from moisture, dust, and changes in atmospheric pressure. --- ## 3. Application Use Cases Because of their high reliability, these parts are found in: 1. **Aerospace:** Landing gear sensors and cockpit controls. 2. **Military:** Trigger mechanisms and munitions arming. 3. **Medical Equipment:** High-precision diagnostic machinery. --- ## 4. Part Number Breakdown Example If you see a part like `311HS1-T`: * **311:** Identifies the series (Integral lever subminiature). * **HS:** Indicates Hermetically Sealed environment protection. * **1:** Specific actuator type/length. * **T:** Termination style (e.g., Solder).