{"product_id":"ky-025-magnetic-reed-switch-sensor-module-with-lm393-for-arduino","title":"KY-025 Magnetic Reed Switch Sensor Module with LM393 for Arduino","description":"\n\u003ch2\u003eKY-025 Magnetic Reed Switch Sensor Module with LM393 for Arduino\u003c\/h2\u003e\n\n\u003cp\u003eBuy the \u003cstrong\u003eKY-025 Magnetic Reed Switch Sensor Module with LM393\u003c\/strong\u003e online in Pakistan from \u003cstrong\u003eRobostan.pk\u003c\/strong\u003e. This compact magnetic detection module is designed for Arduino, ESP32, Raspberry Pi, robotics, smart home automation, security alarm systems, and DIY electronics projects.\u003c\/p\u003e\n\n\u003cp\u003eThe \u003cstrong\u003eKY-025 Reed Switch Module\u003c\/strong\u003e uses a normally open magnetic reed switch that responds to a nearby magnet. When a suitable magnetic field is present, the switch contacts close, changing the electrical signal available to the connected microcontroller.\u003c\/p\u003e\n\n\u003cp\u003eThe module includes an \u003cstrong\u003eLM393 voltage comparator, adjustable potentiometer, analog-labeled output (AO), digital output (DO), and onboard indicator LEDs\u003c\/strong\u003e, providing convenient connections for electronic switching and magnetic detection applications.\u003c\/p\u003e\n\n\u003ch3\u003eKey Features\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003eKY-025 magnetic reed switch sensor module\u003c\/li\u003e\n\u003cli\u003eNormally open (NO) magnetic reed switch\u003c\/li\u003e\n\u003cli\u003eIntegrated LM393 voltage comparator\u003c\/li\u003e\n\u003cli\u003eOperating voltage typically 3.3V to 5V DC\u003c\/li\u003e\n\u003cli\u003eFour-pin connection interface\u003c\/li\u003e\n\u003cli\u003eAnalog-labeled output (AO)\u003c\/li\u003e\n\u003cli\u003eDigital comparator output (DO)\u003c\/li\u003e\n\u003cli\u003eAdjustable comparator reference using onboard potentiometer\u003c\/li\u003e\n\u003cli\u003ePower and detection indicator LEDs\u003c\/li\u003e\n\u003cli\u003eSealed glass reed switch sensor\u003c\/li\u003e\n\u003cli\u003eContactless magnetic activation\u003c\/li\u003e\n\u003cli\u003eCompatible with Arduino digital inputs\u003c\/li\u003e\n\u003cli\u003eSuitable for ESP32 and Raspberry Pi with appropriate interfacing\u003c\/li\u003e\n\u003cli\u003eCompact PCB with mounting hole on common versions\u003c\/li\u003e\n\u003cli\u003eIdeal for magnetic alarms and position detection\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch3\u003eTechnical Specifications\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eProduct Name:\u003c\/strong\u003e KY-025 Magnetic Reed Switch Sensor Module\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eModel Number:\u003c\/strong\u003e KY-025\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eSensor Type:\u003c\/strong\u003e Magnetic Reed Switch\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eSwitch Configuration:\u003c\/strong\u003e Normally Open (NO)\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eComparator IC:\u003c\/strong\u003e LM393\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eOperating Voltage:\u003c\/strong\u003e Typically 3.3V to 5V DC\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eOutput Interfaces:\u003c\/strong\u003e AO and DO\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eDigital Output:\u003c\/strong\u003e HIGH \/ LOW Comparator Signal\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eAO Output:\u003c\/strong\u003e Reed Switch Signal\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eReference Adjustment:\u003c\/strong\u003e Onboard Trimmer Potentiometer\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eCommon Potentiometer:\u003c\/strong\u003e 3296W-104\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eCommon Reed Switch Size:\u003c\/strong\u003e Approximately 2 x 14mm\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eIndicator LEDs:\u003c\/strong\u003e Power and Detection\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eConnection Pins:\u003c\/strong\u003e AO, GND, VCC, DO\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eTypical PCB Dimensions:\u003c\/strong\u003e Approximately 36 x 15mm\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eDetection Method:\u003c\/strong\u003e Magnetic Contact Switching\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eCompatible Platforms:\u003c\/strong\u003e Arduino, ESP32, Raspberry Pi and Other Suitable Microcontrollers\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch3\u003eApplications\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003eArduino magnetic detection projects\u003c\/li\u003e\n\u003cli\u003eDoor and window security alarms\u003c\/li\u003e\n\u003cli\u003eSmart home automation\u003c\/li\u003e\n\u003cli\u003eMagnetic proximity sensing\u003c\/li\u003e\n\u003cli\u003eCabinet and drawer position detection\u003c\/li\u003e\n\u003cli\u003eRobotics position monitoring\u003c\/li\u003e\n\u003cli\u003eMagnetic limit-switch projects\u003c\/li\u003e\n\u003cli\u003eDIY security monitoring circuits\u003c\/li\u003e\n\u003cli\u003eESP32 IoT alarm systems\u003c\/li\u003e\n\u003cli\u003eRaspberry Pi GPIO projects\u003c\/li\u003e\n\u003cli\u003eElectronic switching experiments\u003c\/li\u003e\n\u003cli\u003eEducational sensor projects\u003c\/li\u003e\n\u003cli\u003eEquipment position monitoring\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch3\u003eHow Does the KY-025 Magnetic Sensor Work?\u003c\/h3\u003e\n\n\u003cp\u003eThe \u003cstrong\u003eKY-025 Magnetic Reed Sensor\u003c\/strong\u003e contains two flexible metal contacts enclosed in a sealed glass capsule.\u003c\/p\u003e\n\n\u003cp\u003eIn the absence of a suitable magnetic field, the contacts remain open. When a magnet approaches, the magnetic force causes the contacts to close, completing an electrical connection.\u003c\/p\u003e\n\n\u003cp\u003eThis switching action changes the sensor circuit signal. The onboard LM393 comparator processes the signal and generates a digital output that can be monitored by a microcontroller.\u003c\/p\u003e\n\n\u003cp\u003eThe KY-025 is suitable for detecting the presence or absence of a magnet rather than measuring precise magnetic field strength.\u003c\/p\u003e\n\n\u003ch3\u003eKY-025 Analog and Digital Outputs\u003c\/h3\u003e\n\n\u003cp\u003eThe module commonly provides two output terminals:\u003c\/p\u003e\n\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eAO (Analog-Labeled Output):\u003c\/strong\u003e Provides the electrical signal associated with the reed switch circuit.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eDO (Digital Output):\u003c\/strong\u003e Provides a comparator-controlled HIGH or LOW signal.\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003cp\u003e\u003cstrong\u003eImportant:\u003c\/strong\u003e Although one terminal is labeled AO, the KY-025 uses a mechanical reed switch. This output should not be advertised as an accurate continuous measurement of magnetic field strength.\u003c\/p\u003e\n\n\u003cp\u003eThe onboard potentiometer adjusts the comparator reference level, not the inherent magnetic sensitivity of the reed switch itself.\u003c\/p\u003e\n\n\u003ch3\u003eKY-025 Module Pinout\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eAO:\u003c\/strong\u003e Reed switch signal output\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eGND:\u003c\/strong\u003e Ground connection\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eVCC:\u003c\/strong\u003e Positive power supply\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eDO:\u003c\/strong\u003e Digital comparator output\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003cp\u003eAlways follow the actual PCB pin labels, as connector arrangements can vary between manufacturers.\u003c\/p\u003e\n\n\u003ch3\u003eArduino Compatibility\u003c\/h3\u003e\n\n\u003cp\u003eThe KY-025 is compatible with Arduino UNO, Arduino Nano, Arduino Mega, and other controllers with suitable digital input pins.\u003c\/p\u003e\n\n\u003cp\u003eA typical Arduino UNO wiring arrangement is:\u003c\/p\u003e\n\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eKY-025 VCC:\u003c\/strong\u003e Arduino 5V\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eKY-025 GND:\u003c\/strong\u003e Arduino GND\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eKY-025 DO:\u003c\/strong\u003e Arduino digital pin D3\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eKY-025 AO:\u003c\/strong\u003e Arduino A0, if the second output is required\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003cp\u003eThe Arduino can monitor the digital output using the digitalRead() function and respond when the magnetic switch changes state.\u003c\/p\u003e\n\n\u003cp\u003eApplications include controlling a buzzer, turning on an LED, recording magnetic switching events, or activating a suitable alarm circuit.\u003c\/p\u003e\n\n\u003ch3\u003eESP32 and Raspberry Pi Compatibility\u003c\/h3\u003e\n\n\u003cp\u003eThe KY-025 can also be used in compatible ESP32 and Raspberry Pi projects.\u003c\/p\u003e\n\n\u003cp\u003eWhen working with 3.3V-only GPIO systems, select a suitable module supply and ensure that all output signal levels remain within the controller's permitted voltage range.\u003c\/p\u003e\n\n\u003cp\u003eA Raspberry Pi can monitor the digital output through a GPIO input. If analog sampling is required, an external analog-to-digital converter may be used.\u003c\/p\u003e\n\n\u003ch3\u003eDoor and Window Magnetic Alarm Projects\u003c\/h3\u003e\n\n\u003cp\u003eThe \u003cstrong\u003eKY-025 Reed Switch Module\u003c\/strong\u003e is useful for creating simple magnetic door and window monitoring systems.\u003c\/p\u003e\n\n\u003cp\u003ePlace the sensor near a compatible magnet mounted on a moving door, window, or cabinet.\u003c\/p\u003e\n\n\u003cp\u003eAs the magnet moves toward or away from the sensor, the reed switch changes state. A connected controller can use this information to operate an audible alarm, indicator light, or wireless notification system.\u003c\/p\u003e\n\n\u003cp\u003eDetection distance depends on magnet strength, orientation, mounting position, and the switch characteristics.\u003c\/p\u003e\n\n\u003ch3\u003eKY-025 vs KY-021 Magnetic Reed Switch\u003c\/h3\u003e\n\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eKY-025:\u003c\/strong\u003e A magnetic reed switch breakout commonly equipped with an LM393 comparator, potentiometer, indicator LEDs, and separate output terminals.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eKY-021:\u003c\/strong\u003e A smaller and simpler magnetic reed switch breakout intended for basic digital magnetic detection.\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003cp\u003eChoose the KY-025 when the larger comparator-equipped module is required. For straightforward digital reed contact detection, the KY-021 may be sufficient.\u003c\/p\u003e\n\n\u003ch3\u003eKY-025 vs KY-024 Hall Effect Sensor\u003c\/h3\u003e\n\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eKY-025:\u003c\/strong\u003e Uses a mechanical reed switch that opens and closes in a magnetic field.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eKY-024:\u003c\/strong\u003e Uses a solid-state linear Hall Effect sensor for magnetic field sensing.\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003cp\u003eUnlike the KY-024, the KY-025 does not provide calibrated analog magnetic field measurements.\u003c\/p\u003e\n\n\u003ch3\u003eWhy Choose the KY-025?\u003c\/h3\u003e\n\n\u003cp\u003e\u003cstrong\u003eSimple Magnetic Detection:\u003c\/strong\u003e Detects suitable magnets without physical contact between the magnet and module.\u003c\/p\u003e\n\n\u003cp\u003e\u003cstrong\u003eBuilt-In Comparator:\u003c\/strong\u003e Provides a convenient digital output for microcontroller applications.\u003c\/p\u003e\n\n\u003cp\u003e\u003cstrong\u003eAdjustable Reference:\u003c\/strong\u003e Onboard potentiometer allows adjustment of the digital comparator setting.\u003c\/p\u003e\n\n\u003cp\u003e\u003cstrong\u003eCompact Construction:\u003c\/strong\u003e Suitable for small electronic projects and monitoring systems.\u003c\/p\u003e\n\n\u003cp\u003e\u003cstrong\u003eEducational Value:\u003c\/strong\u003e Useful for learning magnetic switching, digital inputs, comparators, and sensor circuits.\u003c\/p\u003e\n\n\u003ch3\u003eImportant Usage Notes\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003eThe KY-025 uses a mechanical reed switch, not a Hall Effect IC.\u003c\/li\u003e\n\u003cli\u003eMagnetic detection depends on magnet strength and orientation.\u003c\/li\u003e\n\u003cli\u003eThe AO output does not provide calibrated magnetic field strength.\u003c\/li\u003e\n\u003cli\u003eThe potentiometer does not change the magnetic switching characteristics of the reed capsule.\u003c\/li\u003e\n\u003cli\u003eMechanical switch contact bouncing may occur.\u003c\/li\u003e\n\u003cli\u003eSoftware debouncing may be needed for stable detection.\u003c\/li\u003e\n\u003cli\u003eHandle the sealed glass reed switch carefully.\u003c\/li\u003e\n\u003cli\u003eVerify the actual PCB pinout before applying power.\u003c\/li\u003e\n\u003cli\u003eUse a regulated supply within the specified voltage range.\u003c\/li\u003e\n\u003cli\u003eKeep output voltages compatible with the connected microcontroller.\u003c\/li\u003e\n\u003cli\u003eDo not connect high-current loads directly to the sensor outputs.\u003c\/li\u003e\n\u003cli\u003eUse a suitable relay or driver circuit for external loads.\u003c\/li\u003e\n\u003cli\u003eDo not use this module as the sole safety device in critical installations.\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch3\u003ePackage Contents\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003e1 x KY-025 Magnetic Reed Switch Sensor Module with LM393\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003cp\u003eExternal magnet, Arduino board, and connecting wires are not included unless specified separately.\u003c\/p\u003e\n\n\u003ch3\u003eBuy KY-025 Magnetic Reed Sensor in Pakistan\u003c\/h3\u003e\n\n\u003cp\u003eLooking for a \u003cstrong\u003eKY-025 Magnetic Reed Switch Module with LM393 in Pakistan\u003c\/strong\u003e? Shop online at \u003cstrong\u003eRobostan.pk\u003c\/strong\u003e for magnetic sensors, reed switch modules, Arduino electronics, ESP32 boards, Raspberry Pi accessories, robotics components, and DIY electronic project supplies.\u003c\/p\u003e\n\n\u003cp\u003eThe KY-025 is suitable for students, engineers, technicians, hobbyists, and electronics developers working on magnetic detection and automation projects.\u003c\/p\u003e\n\n\u003cp\u003e\u003cstrong\u003eOrder your KY-025 Reed Switch Sensor Module from Robostan.pk\u003c\/strong\u003e with nationwide delivery across Pakistan, including Lahore, Karachi, Islamabad, Rawalpindi, Faisalabad, Multan, Peshawar, and other cities.\u003c\/p\u003e\n\n\u003cp\u003e\u003cstrong\u003eRobostan.pk – Build. Innovate. Create.\u003c\/strong\u003e\u003c\/p\u003e\n","brand":"ROBOSTAN","offers":[{"title":"Default Title","offer_id":68374806495598,"sku":null,"price":130.0,"currency_code":"PKR","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/1019\/7391\/8062\/files\/ChatGPTImageNov13_2026_05_04_40PM-1_6c3171a8-f89a-4745-b456-462c096fd9ee.png?v=1794583656","url":"https:\/\/robostan.pk\/products\/ky-025-magnetic-reed-switch-sensor-module-with-lm393-for-arduino","provider":"ROBOSTAN","version":"1.0","type":"link"}