An electrical or electronic device used to turn on or off the flow of the current in a circuit. The selection of the appropriate switch control for an intended
application is very important. The performance and acceptance of the completed end product can depend on the ability of the switch to handle the electrical
load characteristics of the application without failure over a reasonable amount of time.
Switches are essential components in almost all the electronic devices used today. They are made for both through hole and surface mount applications. They are used in applications as simple as turning something on or off or they are designed for tasks as complex as routing signals. Some basic considerations in the selection of a switch are: Load requirement of the application (Voltage, current, AC/DC, AC only, DC only). Type of load (Resistive, inductive, low energy, dry circuit). Type of duty Environmental conditions.
Switch Circuit - this is the path that the electricy travels. The number of poles is determined by the number of contacts. The number of throws indicates how many positions that are used to direct the current. Here are some examples of the most common styles:
Function - describes additional ability of the switch.
Positions - describes in how many positions switch's actuator can be put.
Voltage Rating - maximum voltage rating.
Current Rating - maximum voltage rating.
Terminals - describes type of switch's terminals. The most common are:
TI Precision Products
(full size & miniature)