Introduction to Electric Switch : Types and Examples

Who could imagine living a day without using an electric switch? It is almost impossible. They are indispensable for the normal functioning of our daily lives and in all types of industries. They are used in controlling the lighting, operating the stove, the refrigerator, television, air conditioner and a thousand other things. Using a switch, we can turn off the devices while not in use, saving energy. Coming to industries, they serve myriad functions and are a part of every machine you can think of, including computers, printers and fax machines.

Electric switches do not always operate under ideal conditions like temperature and pressure. There are places of extreme conditions likezing temperatures and high pressures, where they are expected to work without any problem for years. Take a submarine for example. Here, switches are operated at high pressure and a spacecraft, and the pressure is extremely low. Does that mean the same electric switch we see in our homes can function in adverse conditions like these? Let us find out!

Definition of an Electric Switch

Let us understand the technical definition of an electric switch. An electric switch is a device that makes or breaks the circuit to enable or disable the electric current from flowing. The switch operates depending on whether the system has to start working or stop

How Electric Switches Operate

As mentioned at the beginning, switches either open or close an electric circuit, thereby controlling the flow of electricity. We say an electric circuit is closed when there is a closed path for electricity to flow from the supply to the load. In this condition, the electric switch is ON. When the switch is in OFF position, the electric circuit is OPEN, and there is a gap between the two contacts. It means electricity cannot flow from the power supply to the load. Hence there is no output.

That explains the operation of switches, but have you ever thought about how this happens in an electric switch? It is by varying the levels of resistance of the contacts. We already know that the amount of electricity conducted is inversely proportional to the resistance of the conducting material used. This means the resistance has to be very high for the circuit to remain open and vice versa. In simple words, this is the operating principle of the electric circuit.

Classification of Electric Switches

Depending on how long the switches maintain a particular state (open or closed) and what causes it to change state, Electric Switches may be classified into-

1. Momentary Switch – The switch stays in a particular state until it is energised. When this happens, the switch changes state and returns to the original state when de-energised. Some examples of momentary switches are keys on a keyboard, doorbells, anti-theft alarms, and so on.
   
2. Maintained Switch – This type of switch changes its position only when it is actuated and remains in that state until it is actuated again. A stereo system of the ’80s came with maintained switches.

Types of Electric Switches

Electric switches are of different types, as mentioned below:

1. Electrical Switches: These are primarily used in electrical circuits. They are further classified into Plain Electrical Switch, Fused Switch, Circuit Breaker, and Ground Fault Current Interceptor.
   
2. Electronic Switches: These switches are used whenever electronic circuits need to be connected. We can also use them in connecting electrical circuits with the help of electronic signals. Electronic circuits operate with a specific current or voltage rating. Depending on how many circuits it can connect at a time, they can be further classified into Single Pole Switch, Double Pole Switch, and Multiple Pole Switch.
   
3. Waterproof Switches: Outdoor switches need to be waterproof as they come under rain often. These are very useful in wet conditions as their casing is made with waterproof material.
   
4. DIP Switches: DIP stands for Dual In-line Package. These switches are used when an electronic device needs not just one input but a range of electrical inputs. DIP switches contain multiple electrical switches packed as a single unit.

Applications of Switches in Electronics

What comes to your mind when you hear the word ‘switch’? A light switch, right? Well, we all use many other types of switches in our daily lives without knowing they are switches. Here are some of them:

1. Push-button: You use them every day to get to your office in an elevator. They are nothing but tactile switches.
   
2. Toggle switch: The light switch that we all use every day is the best example of a toggle switch.
   
3. Rocker switch: These are used when a device needs protection from voltage surges, such as a computer display.
   
4. Slide Switch: It operates with the help of a slider. You might have seen them on torch lights.
   
5. Rotary switch: It has a small handle that needs to be turned in a circular motion for it to operate. They were seen on earlier fan regulators and transistors for changing the music station.

What Are Energy Conservation Switches?

Most often, we do not think beyond the basic functionality of an electric switch, which is to turn ON and OFF a device. However, switches play an essential role in energy conservation too! Energy Conservation Switches are the most modern inventions which help us save energy that is otherwise lost when we leave the appliance like fan or AC, ON even while not in use. These switches consume minimum power to operate and can trip/ reset automatically in case of a voltage surge. Energy Conservation Switches are used in hotels, CCTVs and vehicle tracking systems.

We have to understand our responsibilities toward energy sustainability and do our bit in this direction.

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