An electronic switch is an electrical component that can stop or break an electrical circuit by diverting or interrupting the flow of electricity from one conductor to another. The most common type of switch is a manually operated device consisting of one or more sets of electrical contacts. These contacts may be either closed or open. If they are in a closed state the contacts are touching, and this allows the flow of electricity to pass through them. If they are open then the flow of electricity is broken and no electricity can pass through them.
A switch is an electromechanical device, and in its simplest form consists of two pieces of metal that will either touch to complete a circuit or separate to break a circuit. Special consideration is taken to choose the correct material or metal for these contacts as any corrosion from the metal contacts could form insulating oxides that could hinder the conductivity between them, and prevent the switch from working properly.
The materials chosen for contacts are based on their:
o Mechanical strength
o Low toxicity
o Electrical conductivity
One way of keeping these contacts clean is by designing the contacts to brush or wipe together thus helping to clean off any insulating oxides and contamination. Sometimes non-metallic conductors are used made from conductive plastic, and some contacts may even be plated with noble metals.
There are many types of electrical switches, and these are all designed for different uses and applications. Some of the many types of electrical switches can include:
o Knife switch
o Mercury tilt switch
o Biased switch
o Latching switch
o Centrifugal switch
o Timed switch
Electronic timed switches have built in clocks. They are generally placed between the power supply and the electrical device. This allows the connected device to receive power for a set or timed period, and this duration of time can be programmed to switch on and off several times a day. There are two versions available, mechanical and electronic, and both are commonly used for applications such as street lighting, home lighting, washing machines and microwave ovens.