The **SVB-D8W-R/K** is a specialized electronic component, typically categorized as an **Optical Touch Sensor** or an **Optical Switch Module**. These parts are frequently used in elevator control panels, industrial interfaces, and sanitary equipment where non-contact operation is required. Below is a breakdown of its technical specifications and electronic characteristics. --- ### 1. Technical Specifications | Feature | Specification | | :--- | :--- | | **Component Type** | Optical Reflective Sensor / Touchless Switch | | **Operating Voltage** | Typically 12V to 24V DC | | **Output Type** | NPN or PNP Open Collector (model dependent) | | **Sensing Distance** | 0 to 50mm (Adjustable or fixed depending on housing) | | **Indicator LED** | Dual Color (Red/Green or Blue/Green) | | **Connector Type** | Multi-pin header or pre-wired lead | ### 2. Core Electronic Operation The device operates on the principle of **Infrared (IR) Triangulation or Reflection**: * **Emitter:** An internal IR LED emits a modulated beam of light through the front lens. * **Receiver:** A photodiode or phototransistor waits for the light to bounce off an object (like a finger). * **Logic Controller:** An onboard IC filters out ambient light noise to prevent false triggering from sunlight or overhead lamps. * **Output Switching:** Once the signal threshold is met, the internal transistor closes the circuit, signaling the host controller (PLC or Elevator CPU). ### 3. Connection Pinout (Typical) While you should always consult the specific datasheet for the "K" variant, the standard wiring for these modules follows this logic: | Pin/Wire Color | Function | Description | | :--- | :--- | :--- | | **Brown** | +VCC | Positive power supply (12-24V) | | **Blue** | GND | Common ground | | **Black** | OUT | Control signal output (Active Low/High) | | **White/Yellow** | LED Control | Controls the ring light color state | ### 4. Key Applications * **Elevator Buttons:** Used as "touchless" floor selection buttons to improve hygiene. * **Clean Rooms:** Used in medical or semiconductor facilities to trigger doors without physical contact. * **Vandal Resistance:** Because there are no moving mechanical parts, these modules have a much longer lifespan than traditional micro-switches. ---