Mercury Switch Module

SunFounderSKU: TS0198

In stock


Similar to a tilt switch, a mercury switch is used to detect slight inclinations of a large angle. A mercury switch (also known as a mercury tilt switch) is a switch that opens and closes an electrical circuit through a small amount of liquid mercury.
Mercury switches have one or more sets of electrical contacts in a sealed glass envelope that contains a bead of mercury. The envelope may also contain air, an inert gas, or a vacuum. Gravity is constantly pulling the drop of mercury to the lowest point in the envelope. When the switch is tilted in the appropriate direction, the mercury touches a set of contacts, thus completing the electrical circuit through those contacts. Tilting the switch in the opposite direction causes the mercury to move away from that set of contacts, thus breaking that circuit.

The module is mainly applied to tilt detection (e.g. burglar alarm).
More details can be found in

Mercury is harmful to human body and environment. Thus, please be careful when using a mercury switch in case of glass breaking. It should also be properly handled when it's no longer used.


  • A premium switch module suitable for beginners. 
  • Effective in environmental extremes. 
  • PCB size: 2.0 x 2.0 cm. 
  • Working voltage: 3.3-5V; with power light and signal output indicator. 
  • Compact size; with 3-pin anti-reverse cable included. 

Package List

  • Mercury switch module x 1 
  • 3-Pin anti-reverse cable x 1 

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