The **ME28XBG-R** is an **Electro-Mechanical Micro-Switch** produced by Multicomp (a brand under Farnell/Newark). It belongs to the sub-miniature category of switches, primarily used for sensing physical presence, limit detection, or human interface in compact electronic devices. --- ### ## Technical Specifications The following table outlines the key electrical and physical characteristics of the ME28XBG-R: | Feature | Specification | | :--- | :--- | | **Actuator Type** | Simulated Roller Lever | | **Circuitry** | SPDT (Single Pole Double Throw) | | **Switch Operation** | On-(Mom) - Momentary | | **Contact Current Rating** | 5A at 125VAC / 3A at 250VAC | | **Contact Resistance** | 30mΩ Max | | **Insulation Resistance** | 100MΩ Min at 500VDC | | **Operating Force** | ~50g to 150g (Varies by model) | | **Terminal Type** | Solder Terminals | --- ### ## Internal Construction & Operation The ME28XBG-R operates as a **Snap Action** switch. This means the transition of the contacts happens at a specific point of physical travel, regardless of how fast or slow the lever is pressed. 1. **The Lever:** The "BG" suffix typically denotes a simulated roller lever. This allows for smoother actuation when the trigger mechanism moves at an angle or slides across the switch. 2. **Contacts:** It features three pins: * **COM (Common):** The input. * **NC (Normally Closed):** Connected to COM when the lever is at rest. * **NO (Normally Open):** Connects to COM only when the lever is depressed. 3. **Housing:** Made of high-temperature thermoplastic to withstand soldering and industrial environments. --- ### ## Applications Because of its small footprint and reliable snap action, the ME28XBG-R is found in: * **Computer Peripherals:** Mouse buttons or joystick triggers. * **Industrial Automation:** End-stop sensors for 3D printers or CNC machines. * **Home Appliances:** Door interlocks for microwaves or water level sensors in coffee makers. * **Security:** Tamper-detection switches for control panels. --- ### ## Typical Connection Diagram ```cpp // Logic for a Microcontroller (e.g., Arduino) // Connect COM to GND and NO to a Digital Pin with Internal Pull-up void setup() { pinMode(2, INPUT_PULLUP); // Pin 2 connected to NO terminal } void loop() { int switchState = digitalRead(2); if (switchState == LOW) { // Switch is pressed, circuit is closed to GND activateFunction(); } } ```