The **D449-R1RD** is a specific model of a **Miniature Snap Action Switch** (often referred to as a microswitch) manufactured by **Cherry** (now part of ZF Friedrichshafen AG). It belongs to the **D4 series**, which is known for its high reliability and precision. Below is the technical breakdown of its electronic and mechanical components. --- ### 1. Technical Specifications This table highlights the core electrical characteristics of the D449-R1RD: | Feature | Specification | | :--- | :--- | | **Current Rating** | 10 Amps | | **Voltage Rating (AC)** | 250V AC | | **Contact Form** | SPDT (Single Pole Double Throw) | | **Operating Force** | ~45g (Low force variant) | | **Terminal Type** | Quick Connect / Solder | | **Actuator Style** | Long Lever (Roller optional depending on suffix) | | **Operating Temperature** | -40°C to +85°C (up to 150°C for some D4 series) | --- ### 2. Internal Electronic Parts & Construction The "R1RD" suffix dictates the physical configuration of the switch. Here is a breakdown of the internal parts: * **Contacts:** Typically made of **Silver Alloy (AgNi)**. Silver provides excellent conductivity and resists arcing, which is essential for a 10A rating. * **Switching Mechanism:** Uses a **Beryllium Copper** leaf spring. This material is chosen for its "memory"—it returns to its original shape millions of times without snapping, ensuring the "snap action" feel. * **Housing/Case:** Made of **PET (Polyethylene Terephthalate)** or **PBT (Polybutylene Terephthalate)**. These are high-grade thermoplastics that provide electrical insulation and flame retardancy (UL 94 V-0 rated). * **Terminals:** Brass with silver plating to ensure low contact resistance and ease of soldering or connector attachment. --- ### 3. Deciphering the Model Code: D449-R1RD The part number is a composite of its features: 1. **D4:** The Series name (General Purpose Snap Action). 2. **4:** Denotes the rating/contact material (usually 10A, 250VAC). 3. **9:** Indicates the internal configuration/operating force. 4. **R1:** This refers to the **Actuator Type**. "R1" usually signifies a specific length of a flat lever. 5. **RD:** Refers to the **Terminal Configuration** (e.g., right-hand side or specific vertical orientation). --- ### 4. Common Applications Due to its high amperage and reliable snap-action, the D449-R1RD is commonly found in: * **Home Appliances:** Door interlocks for microwaves or washing machines. * **HVAC Systems:** Airflow or pressure sensors. * **Industrial:** Limit switches for CNC machinery or conveyors. * **Vending Machines:** Detection of coin or product movement.