Switch manufacturers tell you that the simplest switch has two pieces of metal called "contact", the two contact contact to make current form a loop, two contacts do not touch the current open. Select the contact metal to be considered when the degree of corrosion resistance, because most of the metal oxide formed after the formation of insulating oxides, so that contacts can not work properly. Switch manufacturers use contact metal must also consider its conductivity, hardness, mechanical strength, cost and whether the toxic and other factors.
Corrosion-resistant metal is sometimes plated on the contacts. Usually in contact with the contact surface to avoid the oxide and affect its performance. Sometimes the contact surface will also use non-metallic conductive material, such as conductive plastic.
Switch manufacturers switch in addition to the contacts, there will be a movable piece to make the contact conduction or non-conduction, the switch according to the different pieces of movable parts for the switch (Toggleswitch), key switch, rocker switch (Rockerswitch) , And the movable member may be other types of mechanical links.
Folding delay switch
Delay switch is the use of electronic components installed in the switch relay, a delay switch circuit switch. Delay switch is divided into voice delay switch, light control delay switch, touch-type delay switch. Delay switch is the principle of the principle of electromagnetic relays, the relay works, when the relay coil power, the coil in the core produces a strong electromagnetic force, attract the armature to drive the reed so that contacts 1,2 open, 1,3 turn on. When the coil power, the spring to reed reset, so that contacts 1,2 turn, 1, 3 off. As long as we need to control the circuit connected to the contacts 1, 2 (1,2 called the normally closed contact) or contacts 1, 3 (known as the normally open contact), you can use the relay to achieve a control the goal of.