{"product_id":"mc-38a-wired-door-window-magnetic-sensor-switch-nc-no-reed-switch-home-alarm","title":"MC-38A Wired Door Window Magnetic Sensor Switch NC NO","description":"\u003cp\u003eThe \u003cstrong\u003eMC-38A Wired Magnetic Door \u0026amp; Window Sensor Switch\u003c\/strong\u003e is a compact, reliable component for home security and automation systems. With both Normally Open (NO) and Normally Closed (NC) reed switch options available, this sensor detects whether a door or window is open or closed by sensing the proximity of its paired magnet — making it an essential building block for DIY alarm systems, smart home setups, and access-monitoring projects.\u003c\/p\u003e\n\n\u003cp\u003eIts slim plastic housing (27 × 14 × 8 mm) fits discreetly on wooden doors, window frames, cabinets, and more. Installation is straightforward via screws or double-sided tape, and each set includes a 350 mm wired lead for easy connection to your alarm panel or microcontroller.\u003c\/p\u003e\n\n\u003ch2\u003eKey Features\u003c\/h2\u003e\n\u003cul\u003e\n  \u003cli\u003e\n\u003cstrong\u003eNC \u0026amp; NO Options:\u003c\/strong\u003e Choose Normally Closed (opens when magnet moves away) or Normally Open (closes when magnet is near) to suit your circuit design\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eCompact Size:\u003c\/strong\u003e 27 × 14 × 8 mm — fits neatly on doors, windows, cabinets, and drawers\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eEasy Installation:\u003c\/strong\u003e Mount with screws or double-sided tape (SMD-style installation)\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003e350 mm Wire Lead:\u003c\/strong\u003e Pre-wired for quick integration into alarm panels and controllers\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eDurable Plastic Housing:\u003c\/strong\u003e Lightweight yet sturdy for long-term everyday use\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eVersatile Application:\u003c\/strong\u003e Ideal for wooden doors, windows, gates, and enclosures\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eAvailable in 2 Colors:\u003c\/strong\u003e Choose the finish that best blends with your interior\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003ePackage Includes:\u003c\/strong\u003e 1 complete sensor set (magnet + switch unit)\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch2\u003eHow It Works\u003c\/h2\u003e\n\u003cp\u003eA reed switch sensor operates using a small internal metal reed. When the paired magnet is brought close, the magnetic field causes the reed contacts to change state. On a \u003cstrong\u003eNormally Open (NO)\u003c\/strong\u003e switch, the circuit closes when the magnet is nearby (door\/window closed) and opens when the magnet moves away (door\/window open). On a \u003cstrong\u003eNormally Closed (NC)\u003c\/strong\u003e switch, the opposite is true — the circuit is closed by default and opens when the magnet is removed. This simple and dependable mechanism is widely used in residential and commercial security systems.\u003c\/p\u003e\n\n\u003ch2\u003eSpecifications\u003c\/h2\u003e\n\u003cul\u003e\n  \u003cli\u003e\n\u003cstrong\u003eModel:\u003c\/strong\u003e MC-38A\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eMaterial:\u003c\/strong\u003e Plastic\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eDimensions:\u003c\/strong\u003e 27 × 14 × 8 mm\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eWire Length:\u003c\/strong\u003e 350 mm\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eSwitch Output:\u003c\/strong\u003e Normally Open (NO) \/ Normally Closed (NC)\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eInstallation:\u003c\/strong\u003e Screws or double-sided tape\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eRecommended Surfaces:\u003c\/strong\u003e Wooden doors, windows\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eColors Available:\u003c\/strong\u003e 2 options\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch2\u003eIdeal For\u003c\/h2\u003e\n\u003cul\u003e\n  \u003cli\u003eDIY home alarm and security systems\u003c\/li\u003e\n  \u003cli\u003eSmart home automation projects\u003c\/li\u003e\n  \u003cli\u003eArduino, Raspberry Pi, and microcontroller builds\u003c\/li\u003e\n  \u003cli\u003eDoor\/window open-close monitoring\u003c\/li\u003e\n  \u003cli\u003eCabinet and drawer access detection\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003cp\u003eFor guidance on home security best practices, visit the Cybersecurity \u0026amp; Infrastructure Security Agency or refer to the U.S. Consumer Product Safety Commission (CPSC) for consumer product safety information.\u003c\/p\u003e\n\n\u003ch3\u003eFrequently Asked Questions\u003c\/h3\u003e\n\u003ch4\u003eQ: What is the MC-38A Wired Magnetic Door \u0026amp; Window Sensor Switch used for?\u003c\/h4\u003e\n\u003cp\u003eA: The MC-38A is a wired magnetic reed switch sensor designed for home security and automation systems. It detects when a door or window is opened or closed by sensing the proximity of a paired magnet. It can be wired into alarm panels, microcontrollers (such as Arduino), or smart home hubs to trigger alerts or automate actions when an entry point is accessed.\u003c\/p\u003e\n\n\u003ch4\u003eQ: What is the difference between NC (Normally Closed) and NO (Normally Open) reed switches?\u003c\/h4\u003e\n\u003cp\u003eA: A \u003cstrong\u003eNormally Open (NO)\u003c\/strong\u003e reed switch has contacts that remain open (circuit off) when no magnet is nearby. When the magnet comes close — such as when a door is shut — the contacts close, completing the circuit. A \u003cstrong\u003eNormally Closed (NC)\u003c\/strong\u003e reed switch works in reverse: the contacts are closed by default and open when the magnet is brought near. The correct type depends on your alarm system or circuit design requirements.\u003c\/p\u003e\n\n\u003ch4\u003eQ: How do I install the MC-38A door\/window sensor?\u003c\/h4\u003e\n\u003cp\u003eA: Installation is simple. Mount the sensor body on the door or window frame, and attach the magnet to the moving door or window itself. Use the provided screw holes or double-sided tape (SMD-style mounting). Align the two pieces so they are within close range when the door\/window is closed. Connect the 350 mm wire lead to your alarm panel or controller. No special tools are required.\u003c\/p\u003e\n\n\u003ch4\u003eQ: What surfaces is the MC-38A sensor compatible with?\u003c\/h4\u003e\n\u003cp\u003eA: The MC-38A is recommended for wooden doors and windows, making it well-suited for most residential interior and exterior doors, window frames, and cabinet enclosures. Its compact 27 × 14 × 8 mm size ensures it fits discreetly on most surfaces.\u003c\/p\u003e\n\u003cscript type=\"application\/ld+json\"\u003e{\"@context\": \"https:\/\/schema.org\", \"@type\": \"FAQPage\", \"mainEntity\": [{\"@type\": \"Question\", \"name\": \"What is the MC-38A Wired Magnetic Door \u0026amp; Window Sensor Switch used for?\", \"acceptedAnswer\": {\"@type\": \"Answer\", \"text\": \"The MC-38A is a wired magnetic reed switch sensor designed for home security and automation systems. It detects when a door or window is opened or closed by sensing the proximity of a paired magnet. 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