## Technical Overview: Omron B3W-9010-R2R The **B3W-9010-R2R** is a specific model of tactile switch manufactured by **Omron Electronics**. It belongs to the B3W series, which is characterized by its integrated LED illumination and a sealed structure that provides high reliability in dusty or damp environments. ### 1. Key Component Specifications | Feature | Specification | | :--- | :--- | | **Switch Type** | Tactile Switch (SPST-NO) | | **Illumination** | Integrated LED | | **LED Color** | Red (Single Color) | | **Cap Color** | Red | | **Operating Force** | 1.57 N (approx. 160 gf) | | **Contact Rating** | 1 to 50 mA, 5 to 24 VDC | | **Sealing Rating** | Equivalent to IP67 (Dust-tight, Water-resistant) | | **Termination Style** | Through-hole (PCB) | --- ### 2. Functional Design The B3W-9010-R2R is engineered with three primary internal systems: #### A. Contact Mechanism * **Tactile Feedback:** Utilizes a snap-action metal dome that provides a crisp "click" when actuated. * **Sealed Construction:** The internal switching mechanism is protected by a rubber boot or membrane, preventing flux or liquid ingress during the soldering process or end-use. #### B. Illumination System * **Internal LED:** The LED is embedded within the switch body. * **Independent Circuitry:** The LED pins are separate from the switch pins, allowing the light to be controlled independently (e.g., staying on constantly or blinking upon press). * **Diffused Cap:** The red cap acts as a light diffuser to ensure even brightness across the surface. #### C. Electrical Pinout Typically, this switch has 6 pins: 1. **Switch Terminals (2 pins):** Closed when the button is pressed. 2. **LED Terminals (2 pins):** Anode and Cathode for the red LED. 3. **Dummy/Support Terminals (2 pins):** Used for mechanical stability on the PCB. --- ### 3. Application Use Cases Due to its illuminated nature and high durability, it is commonly found in: * **Industrial Controls:** Status indicators on control panels. * **Medical Equipment:** Interface buttons that require sterilization or liquid resistance. * **Consumer Electronics:** Power buttons or mode selectors where visual feedback is required. --- ### 4. Typical Circuit Integration When integrating the B3W-9010-R2R, you must use a current-limiting resistor for the LED. ```cpp // Example: Basic LED Calculation for 5V System // LED Forward Voltage (Vf) approx: 2.0V // Desired Current (If): 10mA (0.01A) // Resistor = (Source Voltage - Vf) / If // Resistor = (5V - 2.0V) / 0.01A = 300 Ohms ```