How does a switch works?

Answer 1

A thermostatic switch works by turning on when the temperature is below a certain point. A thermostatic switch will also turn off when the temperature reaches a certain point. Thermostatic switches are used for space heaters so that they do not overheat.

Answer 2

Closed - a switch allows the flow of electricity. Open - a switch breaks the flow of electricity.

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If you get a chance to visit a science museum ask them to show you a "knife switch". Another place to see one is the Physics Lab at your local college or high school. Once you have seen a knife switch you will understand exactly how a basic switch works.

It's quite simple really: a switch is a device which can be used to make or break a circuit. If that circuit carries a voltage which would be dangerous to people or animals then the handle of the switch must be made of a good insulator and the rest of the switch must be well shielded to stop anything else touching any live wires.

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A switch has two conductive pieces, usually made of metal, called contacts that touch to complete (make) a circuit, and separate to open (break) the circuit. The contact material is chosen for its resistance to corrosion, because most metals form insulating oxides that would prevent the switch from working. Contact materials are also chosen on the basis of electrical conductivity, hardness (resistance to abrasive wear), mechanical strength, low cost and low toxicity.

As well as being operated by humans, special switches can be operated by sensors which measure process variables such as pressure, temperature, flow, current, voltage and force. Such sensor-operated switches are used to control those processes automatically.