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MC-38 - Magnetic Switch for Home Alarm System

Description of MC-38

The MC-38 magnetic switch sensor comes in a pair consisting of a Reed Switch and a magnet. The wired part of the module is the reed switch, whereas the other part is the magnet. It is commonly used as a home security alarm system.


Features and Specifications of MC-38

Below are some features and specifications of the MC-38 magnetic switch.

  1. Rated current: 100mA 
  2. Power rating: 3W
  3. Operating distance: 15 - 25mm
  4. Cable Length: 30.5cm ± 12mm
  5. Sensor Output: Normally Closed(NC) (Switch is closed when the switch and magnet are together)


Alternatives of MC-38

MC-56, YL-333


Note: More technical information can be found in the MC38 Datasheet linked at the bottom of this page.


Pinout of MC-38 and Connections with MCU

The MC-38 can be connected to a microcontroller or a processor pretty easily. The Reed Switch part has 2 outputs- Ground and Signal.

MC-38 Connections with MCU

Note: The magnetic switch is non-polar, there is no specific pinout. You can connect the switch’s ground and signal cable in any order.


Working of MC-38

The working of the MC-38 module can be understood by the image below-

MC-38 Magnetic Switch Working

In the left half of the image, the magnet is at a distance to the switch, which prevents the metal reeds to go closer and complete the circuit. Whereas, on the other half of the image, it can be seen that when the magnet is closer to the switch, the metal reeds get connected to one another and the circuit is completed and we observe an output through the sensor module.

To summarise, when the magnet is close by, the circuit is closed and we obtain an output, and when the magnet is far from the reed switch, the circuit is open and we do not get an output


Applications of MC-38

Here are some of the applications of this MC-38 module.

  1. Can be used at doors or windows to know the open and closed state
  2. Used to detect an intruder activity
  3. Home Alarm system


2D Model of MC-38

Below is the 2D model of the MC-38 module. It can be used to design custom footprints and be used in custom-designed printed circuit boards or CAD models.

MC-38 Magnetic Switch Dimensions

Note: All the dimensions are in millimeters.

Component Datasheet

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