Reed Switch | NC Wired Contact Sensor | Home Security Alarms

This RC-33 magnetic reed switch is a simple sensor for monitoring doors and windows in a security system. It's designed to be recessed. This means it sits flush inside the door and frame for a clean, hidden installation. When the door opens, the magnet moves away. The switch then triggers your alarm. Features and Benefits - Recessed flush-mount design - It installs inside the door and frame. This makes the wired door contact sensor almost invisible. - Normally Closed (NC) circuit - This is a fail-safe for alarms. The circuit is closed when the door is shut. Opening the door or cutting the wire breaks the circuit and triggers the alarm. - Simple two-part system - The magnetic reed switch has just a magnet and a switch. This makes it straightforward to install with a drill. - Wired connection - It provides a direct, stable signal to your alarm panel or microcontroller. There are no batteries to change or wireless signals to drop. Applications - Home security alarms - This is a standard part for securing entry points. Connect it to any wired burglar alarm system to detect when doors or windows open. - DIY smart home projects - Link it to an Arduino or other board. This creates custom alerts, turns on lights, or logs activity when a door is accessed. - Cabinet and safe monitoring - Install it on cabinets, drawers, or safes. Get an alert if they are opened without permission. What It Is This product is a magnetic reed switch, specifically the RC-33 NC Recessed Wired Window Door Contact Sensor Detector. It functions as a proximity sensor, meaning it detects the presence or absence of an object without physical contact. This particular model operates as Normally Closed (NC), meaning the electrical circuit is complete when the magnet is in proximity. It is a wired device, designed for low voltage applications, below 50Vac or 75Vdc. It is available to purchase as a single unit or in packs of five. Key Uses & Applications This reed switch is primarily used in home security and burglar alarm systems. Its recessed mounting type makes it suitable for discreet installation in door and window frames. When the door or window opens, the magnetic contact is broken, triggering the alarm. As a proximity sensor, it provides a reliable means of detecting unauthorised entry. Other applications within a security system might include monitoring cabinet doors or other access points where a simple open/close detection is required. How to Choose When selecting a reed switch, consider the intended application. For home security or burglar alarms, this NC wired contact sensor is a suitable choice, especially for recessed installations in windows and doors. Verify the voltage requirements of your system; this product is designed for low voltage use (below 50Vac or 75Vdc). To test a proximity sensor like this, you would typically connect it to a multimeter to observe the circuit status (open or closed) as a magnet is brought near and then moved away. For larger installations, consider the available quantity options.