The **SV-154-R** is a specific model of a **Miniature Micro Switch** (often associated with the Omron V-series or similar industrial clones) used extensively in automation, security, and consumer electronics. It is a snap-action switch designed for high reliability. --- ### 1. Key Technical Specifications The "R" suffix typically denotes a specific actuator style (usually a Roller Lever) or a specific terminal orientation. | Feature | Specification (Typical) | | :--- | :--- | | **Actuator Type** | Short Hinge Roller Lever | | **Contact Form** | SPDT (Single Pole Double Throw) | | **Current Rating** | 5A to 15A (Depending on voltage) | | **Voltage Rating** | 125VAC / 250VAC | | **Operating Force** | ~1.23 N (approx. 125g) | | **Terminal Type** | Solder or Quick Connect (#187) | --- ### 2. Electronic Internal Configuration The switch functions as a **SPDT** device, meaning it can control two different circuits or be used to signal "On/Off" states. * **COM (Common):** The input terminal where the power enters. * **NO (Normally Open):** The circuit is broken until the lever is pressed. * **NC (Normally Closed):** The circuit is complete until the lever is pressed. --- ### 3. Component Breakdown #### A. The Housing Usually made of **Phenolic or PBT (Polybutylene terephthalate)** plastic. This provides high heat resistance and electrical insulation to prevent arcing between terminals. #### B. The Roller Lever (The "R" Part) The "R" stands for **Roller**. Instead of a flat metal leaf, it features a small plastic or metal wheel at the end of the lever. * **Purpose:** Reduces friction and wear when the switch is triggered by a cam or a moving mechanical part. * **Application:** Ideal for sensing the position of a sliding door or a rotating gear. #### C. Snap-Action Mechanism Inside, a beryllium copper spring is used. This ensures that the contacts snap from one position to the other instantly, regardless of how slowly the lever is pressed. This prevents "arcing" (sparks) that would otherwise burn out the contacts. --- ### 4. Common Applications * **Industrial:** Limit switches in CNC machines or 3D printers. * **Safety:** Interlock switches in microwave doors or washing machines. * **Automation:** Conveyor belt object detection. --- ### 5. Wiring Logic Example If you are using this with a microcontroller (like an Arduino): ```cpp // Example: Detecting if a door is closed using SV-154-R int switchPin = 2; // Connected to NO terminal void setup() { pinMode(switchPin, INPUT_PULLUP); // Use internal resistor Serial.begin(9600); } void loop() { int status = digitalRead(switchPin); if (status == LOW) { Serial.println("Door Closed / Switch Triggered"); } } ```