Basic Knowledge of Switch
Whenever we enter a room, What is the first thing we usually do?
We switch - on the light or a fan - isnt it ?
If we feel cold, then the first thing we do is to switch off the fan.
All the electrical devices we use at home are connected to switches.
To start any electrical device, all we do is 'switch it on' and to stop it, we just 'switch it off'.
Electrical switches are simple yet very important electrical devices.
Electrical switches can either break or make a circuit.
Let us make our own Electrical Switch and understand it's working
We can make a simple switch using two drawing pins, a safety pin, two wires and a small sheet of thermocol.
First let's take one drawing pin and insert it into the ring at one end of the safety pin and fix them into a thermocol.
We have to make sure that, safety pin is not very tightly fixed and it should rotate around the drawing pin.
Now let's take the second drawing pin and fix it on the thermocol sheet.
The free end of the safety pin can touch the second drawing pin while rotating. Thus, we made a simple switch using a safety pin
Let's check whether this switch is working or not. For this, we need an electric cell and a bulb.
Now let's attach one end of each wire to the drawing pins.
The other end of wires are connected to an electric cell and bulb.
Now let's rotate the safety pin so that its free end touches the other drawing pin as shown.
What will we observe ??
Yes! The bulb will start to glow.
Now, if we move the safety pin away ... does the bulb continue to glow?
Thus, we have made our first electrical circuit with our first electrical switch!
Now why does the safety pin behave as a switch ?
When the safety pin touches both the drawing pins, the circuit is closed.
In a closed circuit, current can flow and the bulb glows. In this position the switch is said to be in 'on' position.
On the other hand when the safety pin is moved away, the circuit is not complete and is called 'open'.
In an open circuit, current doesn't flow, and the bulb doesn't glow. Here the switch is said to be in 'off' position.
Wasn't making a simple switch easy and interesting?
Let's take a small REVISION
An electrical switch is a commonly used device for making, breaking, or changing the course of an electric circuit.