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:
Alcoswitch
Alps
APEM
Aromat
AMP
Arrow-Hart
Augat
Bourns
C&K
CRL
CTS
Cutler-Hammer
CW Industries
E-Switch
Eaton
EECO
Grayhill
Hamlin
Honeywell/Microswitch
ITT Cannon
Interswitch
Leach
Linemaster
Marquardt
Mepcopal
NKK
Omron
Otto
Panasonic
Selecta Switch
Square D
Switchcraft
Therm-O-Disc/ McGill
Tocos
TI Precision Products
Xicon
Detector Switches
Dip Switches
Keylock Switches
Leaf Switches
Snap-Action Switches
Slide Switches
Tact Switches
Toggle Switches
(full size & miniature)