The **ALSP-233-R/Q** is a specific surface-mount (SMD) tact switch commonly used in consumer electronics, automotive interfaces, and industrial controls. It belongs to a category of momentary switches designed for high durability and a small footprint. --- ### 1. Technical Specifications The following table summarizes the core electronic and physical characteristics of the ALSP-233-R/Q: | Feature | Specification | | :--- | :--- | | **Type** | Momentary Tactile Switch | | **Mounting Type** | Surface Mount (SMD / SMT) | | **Circuit Type** | SPST (Single Pole, Single Throw) | | **Actuation Force** | Typically 1.6N to 2.5N (160gf - 250gf) | | **Contact Rating** | 50mA @ 12V DC | | **Contact Resistance** | < 100 mΩ | | **Operating Life** | 100,000 to 500,000 cycles (model dependent) | | **Travel** | 0.25mm ± 0.1mm | --- ### 2. Key Internal Components The functionality of this part relies on three primary internal sections: 1. **Contact Dome (The Heart):** This is a stainless steel or phosphor bronze disc. When pressed, it collapses to complete the circuit and provides the "click" tactile feedback. 2. **Base (Housing):** Usually made of high-temperature resistant thermoplastic (LCP or Nylon) to survive the IR reflow soldering process. 3. **Terminals:** Silver-plated brass or copper alloy leads that ensure high conductivity and ease of soldering to the PCB. --- ### 3. Part Number Suffix Breakdown In the electronics industry, suffixes often denote specific packaging or physical variations: * **-R:** Usually indicates **Tape and Reel** packaging, which is necessary for high-speed automated pick-and-place assembly machines. * **-Q:** Often refers to specific **Operating Force** or **Contact Material** (Silver plating), though this can vary slightly by manufacturer. --- ### 4. Circuit Diagram The switch acts as a simple bridge between two pads on a PCB. ```text [ Terminal 1 ] ----\ ---- [ Terminal 2 ] | (Tactile Dome) | [ Terminal 3 ] ----/ ---- [ Terminal 4 ] ``` *Note: In most 4-pin tact switches, Terminal 1 is internally connected to Terminal 2, and 3 is connected to 4. Pressing the button bridges the 1-2 pair to the 3-4 pair.* ---