switch
close The simplest switch being loaded has two pieces of metal called "contacts". When the two contacts contact, the current forms a loop. When the two contacts do not contact, the current opens. When selecting contact metal, it is necessary to consider the degree of corrosion resistance, because most metals will form insulating oxides after oxidation, making the contact unable to work normally. Factors such as conductivity, hardness, mechanical strength, cost and toxicity should also be considered when selecting contact metal. Corrosion resistant metal is sometimes plated on the joints. Generally, it will be plated on the contact surface of the contact to avoid affecting its performance due to oxide. Sometimes non-metallic conductive materials, such as conductive plastics, are used on the contact surface. In addition to the contacts, there will also be movable parts to make the contacts conductive or non-conductive. The switches can be divided into Toggleswitch, key switch, Rocker switch, etc. according to the different movable parts, and the movable parts can also be other types of mechanical links.