Magnetic Reed Switch Sensor Board Ky0025

The KY-0025 Magnetic Reed Switch Sensor Module is a simple magnetic proximity sensor designed to detect the presence of a magnetic field. It uses a reed switch, which is a mechanical switch enclosed in a glass tube that closes or opens when exposed to a magnet. When a magnet comes close to the sensor, the reed switch changes state, producing a digital signal that can be read by microcontrollers such as Arduino, ESP32, and other 3.3V/5V systems. Most versions of the module include an onboard LM393 comparator circuit, which converts the switch action into a clean digital output signal and often provides an adjustable sensitivity threshold. This module is widely used in basic electronic projects and automation systems for detecting door or window opening/closing, position sensing, and simple security applications. Its straightforward operation, low power consumption, and easy integration make it suitable for both beginners and prototyping environments.