The Basic Structure Of The Switch

The simplest switch has two pieces of metal called "contacts", the current forms a loop when the two contacts are in contact, and the current is open when the two contacts are not in contact. Contact metals need to be selected to consider their degree of corrosion resistance, because most metals oxidize to form insulating oxides, making the contacts unable to function properly. The selection of contact metals also needs to consider its conductivity, hardness, mechanical strength, cost and whether it is toxic. Corrosion-resistant metals are sometimes plated on the contacts. Generally, it is plated on the contact surface of the contact to avoid affecting its performance due to oxides.

Sometimes the contact surface also uses non-metallic conductive materials, such as conductive plastics. In addition to the contact, there will also be movable parts to make the contact on or not, the switch can be divided into lever switch (Toggle switch), key switch, Rocker switch, etc. according to the different movable parts, and the movable part can also be other types of mechanical connecting rods.