DPST: Double Pole Single Throw):
It is like having two SPST configuration which is centrally controlled. It has some specialized applications.
DPDT: Double Pole, Double Throw:
This is nothing but two SPDT switches being controlled by a single mechanism.
DPCO: Double Pole Change Over:
They are like DPDT Switches but have a very stable center position.
2P6T: Two-Pole, Six Throws:
We bet most of us living in rural or area where phase changes are required have seen this type of switch, basically its a change over switch, it helps us in switching from one source of current to another.
In this type of switch, a very small current and generally for a smaller time is desired. It is spring loaded. When we push the button the circuit remains operative till its pushed.
A simple lever operated switch, Generally has two positions but toggle switch which have 3 positions are also common.
Mercury Tilt Switch:
It is a special type of switch with a very specialized application. It has a drop of mercury enclosed in a glass tube. It completes the circuit when mercury moves and joins the terminals. It is basically used where motion is in to play.
It is made up of a hinged metal plate which is flat. One end is properly insulated for safety purpose. When the switch is closed when the current flows through the contact. Copper, steel or brass is the preferred choice of metals for this type of switch.A complete array of such blades are operated with a single lever. In many cases, a spring is also used for maintaining the ease of operability.
As the name suggests, it is a switch which is operated by the pressure of feet. If you have seen the small electric car that kids use, then you can see that the accelerators in these cars are nothing but a foot switch.