The **MA74FAD-R** is a specific electronic component typically identified as a **tactile switch** (or tact switch) manufactured by companies like **Marushin Electric Mfg**. It is designed for PCB (Printed Circuit Board) mounting and is used to provide user input through a physical "click" action. --- ### 1. General Specifications The following table outlines the typical technical parameters for this series of components: | Feature | Specification | | :--- | :--- | | **Component Type** | Tactile Switch (Push Button) | | **Mounting Type** | Through-hole (DIP) | | **Circuitry** | SPST (Single Pole Single Throw), Normally Open | | **Contact Rating** | Usually DC 12V / 50mA | | **Operating Force** | 1.0N to 2.5N (depending on specific sub-variant) | | **Travel Distance** | 0.25mm to 0.3mm | | **Operating Life** | ~100,000 Cycles | --- ### 2. Breakdown of the Part Number While specific manufacturer codes can vary, the nomenclature typically follows this logic: * **MA74F**: The series designation, indicating the physical footprint and internal mechanism. * **A**: Often refers to the terminal shape (e.g., straight pins for PCB). * **D**: Usually denotes the height of the plunger (the part you press). * **-R**: Generally indicates the packaging method (e.g., "RoHS" compliant or "Reel/Radial" taping). --- ### 3. Internal Construction A tactile switch like the MA74FAD-R consists of several key layers: 1. **Cover**: Protects the internal mechanism. 2. **Plunger**: The plastic component that moves downward when pressed. 3. **Contact Dome**: A metal disc that snaps downward to complete the circuit and provides the "tactile" feedback (the click). 4. **Base**: Houses the terminals and holds the assembly together. 5. **Terminals**: The metal pins that are soldered to the PCB. --- ### 4. Common Applications Due to its small footprint and reliability, this part is found in: * **Consumer Electronics**: Remote controls, microwave panels, and audio equipment. * **Industrial**: Reset buttons on control boards. * **Computing**: Power buttons or reset switches on motherboards and peripherals. --- ### 5. Circuit Symbol In a schematic, this part is represented as: ```text / ---o o--- (Switch) ```