The **KUS-44-R** is an ultra-miniature, high-performance side-actuated push button switch, typically manufactured by companies like **STEC** or specialized electronic component suppliers. It belongs to the tactile switch family, designed for space-constrained PCB (Printed Circuit Board) applications. --- ### 1. Key Technical Specifications The electrical and mechanical characteristics are critical for integration into electronic circuits. | Feature | Specification | | :--- | :--- | | **Switch Type** | Tactile Switch (Momentary) | | **Actuation Direction** | Side-actuated (Right Angle) | | **Mounting Type** | Surface Mount (SMD / SMT) | | **Contact Rating** | 50mA, 12V DC | | **Insulation Resistance** | 100MΩ Min at 100V DC | | **Dielectric Strength** | 250V AC for 1 minute | | **Operating Force** | Typically 1.6N (±0.5N) | | **Travel** | 0.25mm | --- ### 2. Physical Design & Composition The "R" in the part number usually signifies a specific packaging or orientation (often **Tape & Reel** or **Right Angle**). * **Contacts:** Usually made of silver-plated phosphor bronze or stainless steel to ensure low contact resistance and high reliability. * **Housing:** High-temperature thermoplastic (LCP or Nylon) designed to withstand lead-free reflow soldering processes. * **Size:** Extremely small footprint (often around 4.5mm x 2.2mm or smaller), making it ideal for wearables. --- ### 3. Circuit Application In an electronic circuit, the KUS-44-R is used as a **Normally Open (N.O.)** momentary switch. When the button is pressed, it completes the circuit; when released, the internal spring mechanism breaks the connection. #### Typical Connection Code Example When connecting to a microcontroller (like an Arduino or ESP32), a pull-up resistor is used to prevent "floating" inputs. ```cpp const int buttonPin = 2; // Pin connected to KUS-44-R void setup() { pinMode(buttonPin, INPUT_PULLUP); // Internal resistor keeps pin HIGH } void loop() { int buttonState = digitalRead(buttonPin); if (buttonState == LOW) { // Switch is pressed, circuit completed to Ground } } ``` --- ### 4. Common Applications Due to its side-actuated design, it is frequently used on the edges of devices: 1. **Consumer Electronics:** Volume buttons on smartphones or tablets. 2. **Wearables:** Smartwatches and fitness trackers. 3. **IoT Devices:** Reset buttons or mode selectors on compact sensors. 4. **Medical Tools:** Handheld diagnostic equipment.