MC38A Door sensor Normally Closed NC

High-Reliability Magnetic Intrusion Detection

The MC-38 Wired Surface Mount Door Window Sensor is an essential component for residential, commercial, and industrial security alarm systems. Built with a durable ABS housing and a high-sensitivity magnetic reed switch, this sensor accurately detects the opening and closing of doors, windows, gates, and equipment enclosures. Designed for clean surface mounting, the low-profile white enclosure seamlessly integrates into standard door frames while providing continuous perimeter monitoring.

Operating Principle and Technical Performance

This sensor utilizes a Normally Closed (NC) contact configuration. When the matching magnet module is aligned within the 18mm (+/- 6mm) activation distance, the internal reed switch remains closed, maintaining loop continuity across your security zone. Separating the magnet from the sensor breaks the magnetic field, opening the circuit and instantly triggering your alarm panel, microcontroller, or automation controller. Engineered to operate at voltages up to 100V DC with a maximum load current of 300mA and a 5W power rating, the MC-38 handles low-voltage alarm signaling with exceptional long-term stability.

Versatile Integration and Smart Automation

Featuring compact 27 x 14 x 8 mm dimensions and pre-drilled mounting holes, the MC-38 connects easily to standard burglar alarm panels, access control systems, or DIY development boards like Arduino, Raspberry Pi, and ESP32. Beyond perimeter security, it is widely applied in smart home automation setups, server rack door monitoring, cabinet lighting control, and industrial machinery safety interlocks.