100 Pack SW420 Normally Closed Vibration Switch Sensor Overview A pack of 100 SW420 normally closed vibration switches designed for straightforward vibration and impact detection in electronics projects and equipment monitoring. Each sensor provides a simple mechanical switch output that changes state when subjected to vibration or shock. Key benefits Ready for batch projects and prototyping: 100 identical sensors in one pack saves time when populating multiple devices or building many prototypes. Simple digital output: acts as a mechanical switch that changes state on vibration, making it easy to integrate into microcontroller, alarm, and control circuits without signal conditioning. Compact and lowprofile: suitable for spaceconstrained enclosures and small devices where a discreet vibration sensor is required. Costeffective and consistent: identical SW420 units provide repeatable behavior across multiple channels or devices. What it does Normally closed operation: the switch remains closed at rest and opens when vibration or impact moves the internal contact. This makes it easy to detect the transition as an event. Mechanical switch output: no active electronics on the sensor itself, so it is compatible with a wide range of input circuits that read mechanical contacts. Compatibility and interface Works with common microcontroller platforms and digital input circuits, including Arduino and Raspberry Pi based projects. Twoterminal connections allow direct use as a digital input or as part of a relay, alarm, or monitoring circuit. Intended for lowvoltage signallevel applications and logiclevel inputs; use with appropriate pullup or pulldown arrangements depending on your system design. Attributes Model: SW420, normally closed vibration switch Quantity: 100 pieces per pack Color: blue housing Construction: plastic housing with internal metal contact mechanism designed to respond to vibration and impacts Output type: mechanical switch change of state on vibration Practical applications Security and antitamper sensing: detect opening, movement, or tampering of cabinets, boxes, and enclosures and trigger alarms or logging events. Machine and equipment monitoring: detect start, stop, or abnormal vibration patterns in pumps, motors, and small machines to feed into maintenance logic or simple monitoring systems. DIY electronics and robotics: add impact detection, collision sensing, or motiontriggered actions to robots, hobby projects, and interactive installations. Integration tips the SW420 as a normally closed contact when wiring. Use a digital input with a pullup or pulldown resistor to read state changes reliably. Mount the sensor securely to the part whose vibration you want to detect; positioning and mounting affect sensitivity and response. For noisy environments or precise measurement, combine the switch with debounce logic or simple filtering in software. What is included 100 units of SW420 normally closed vibration switch, blue housing. This pack provides a practical, repeatable vibration sensing element for electronics projects, monitoring tasks, and bulk assembly where a simple mechanical vibration switch is the preferred solution.