Mercury Switch Tilt Sensor Unidirectional 5mm
Mercury switches or Mercury Tilt Switches are switches that open and close an electrical circuit when it is tilted at certain angles. When it is tilted a small amount of the liquid metal mercury makes contact with metal electrodes to close the circuit.
Mercury switches have one or more sets of electrical contacts in a sealed glass envelope which contains a bead of mercury. 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 the opposite direction causes the mercury to move away from that set of contacts, thus breaking that circuit. The switch may contain multiple sets of contacts, closing different sets at different angles, allowing, for example, single-pole, double-throw (SPDT) operation.
Mercury switches are sensitive to gravity so may be unsuitable in portable or mobile devices that can change orientation or that vibrate.
**Devices containing mercury switches must be treated as hazardous waste for disposal**