Types of Switches

Types of Switches

A switch is a device which turns ON and allows current to flow through the electrical circuit and OFF to break the flow. Generally there are two types of switches: Mechanical and Electrical. Electrical switches work under the influence of semiconductors and Mechanical ones require manual contact with the switch for operation and are classified into various types depending upon the poles (no.of input circuit available to the switch) and throws (no of path for the flow of current available to the switch).

Mechanical switches are classified into:

  • Single Pole Single Throw
  • Single Pole Double Throw
  • Double Pole Single Throw
  • Double Pole Double Throw
  • Two Poles Six Throw
  • Momentary control switches like
  • Push button
  • Pressure switch
  • Temperature switch
  • Toggle switch
  • Rotary switch

Single Pole Single Throw

This is the most simple example of switch and has one input terminal called pole and one output terminal called throw. This switch is used in single loop or one closed path.

Single Pole Double Throw

It has one input terminal and two output terminals and can also be used as selector switch which means we can supply current to two loops.

Double Pole Single Throw

These are used to control the two circuits at the same time. It has two input terminals and two output terminals. In this types of circuits, the two switches are connected with a single lever and operates at the same time.

Double Pole Double Throw

This consists of six terminals, two input terminals(poles) and four output terminals(throw), two for terminal for each pole. In this, one pair of output (throw) is connected with two terminal of input (pole).

Two Pole Six Throw

It has one input terminal (pole) and six output terminal (throw) for each pole. That means total 12 output terminal. This is used for changing over feature for same input terminals in the circuit.

Push Button Switch

When it is pressed, the circuit gets closed for the flow of current. When pressure is removed from the switch, the contact is breaked and the flow of current is stopped.

Pressure Switch

This is used to increase or decrease pressure from a set point. It consists of C-shaped diaphragm and is used in industries to sense pressure of air, water or oil.

Temperature Switch

This consists a resistance temperature device which senses temperature and is operated according to the value of measuring temperature.

Toggle Switch

This has a lever which is moved up and down for turning ON and OFF and is used for household applications.

Rotary Switch

This switch is pretty much self explanatory and are used in channel selector or range selector or band selector. Here, switch is used to connect one line to one among many lines.

These were some types of switches, if you wish to know more, download BYJU’S The Learning App


Practise This Question

If the power of two lenses and P1 and P2; when they are combined; the effective power is: