A two way switch as the name suggests, works both ways. As mentioned in my previous article, two way switches works in pairs. You have to have two, two way switches to make it work the way it is meant to work.
Lets imagine the stairway or our house. When we retire for the night, and make our way to the bedroom at the upper floor, we normally will switch off the stairway lights to save on a little bit of electricity. If we have a normal switch at the bottom of the stairway, we will not be able to do that. On the other hand, if we install the switch at the top of the stairway, then we will not be able to switch it on when we want to go up. That is where a two way switch comes in most useful.
As said, two way switches works in pairs. One will be located at the bottom of the staircase and the other at the top. When we want to go up, we switch the lights on with the switch at the bottom of the staircase, when we reach the top, we use the other switch located at the top to switch off the same light. It makes life real easy for us.
This arrangement is also very useful for corridors of buildings like schools, or hotels. Some which has really long corridors uses the 3 way switch. In this case, there will be another switch located along the center point of the corridor, so if people don’t really need to right up to the end of the corridor to switch off the lights.
The wiring installation for these kind of switches is a little bit different from normal switches as it involves a couple of extra wires to enable both the switches to work in tandem. This will be discussed in later articles.