From the basics to applications of Automation Controls
Filled with valuable information helpful for engineers!

click here for the "SELECTION GUIDE" list page



Introduction to Switches - What Are Switches?

What are switches?

In short,

Switches refer to 'electrical components that turn electrical circuits ON and OFF.'





Types of Switches

Switches are broadly divided into two types.

Operation Switches
Switches used to turn circuits ON and OFF manually
Detection Switches
Switches used to turn circuits ON and OFF using an object
  • Switches to turn lighting ON and OFF
  • Switches to turn TVs ON and OFF
  • Switches to turn photocopiers ON and OFF
  • Switches to open/close car windows
  • Sold-out detection switches for vending machines
  • Switches to detect the position limits of UFO CATCHER game machines
  • Switches to turn the image on video camera monitors upside down
  • Switches to detect the opening and closing of photocopier doors


Basic Contact (Circuit) Arrangement


Form A contacts
(normally open contacts):
N.O. (Normally Open) contacts

Contacts that normally open (OFF state) and
close (turn ON) the circuit when actuated


Form B contacts
(normally closed contacts):
N.C. (Normally Closed) contacts

Contacts that normally close (ON state)
and open (turn OFF) the circuit when actuated


Form C contacts
(transfer contacts):
Transfer contacts (a combination of Form 1A
and Form 1B contacts)

Transfer contacts with both Form A and
Form B contact functions