Practical Examples of Open and Closed loop Control System

In this post, we shall not be looking into any historical advancement that has taken place in the Control engineering field for these many years (you can refer wiki anytime for those details).

So let’s start understanding Control System in layman’s terms . I believe that anyone should start digging into any new subject(for conceptual clarity) by the virtue of real-life practical examples.

Hence it is indeed inevitable for us to relate this subject with some practical examples. ( later on, on this page you’re going to get some basic easy examples of Open and Closed-loop system)

1. We can first consider the cooking process as a very good example of this. We first decide what to prepare, then we start cooking by adding vegetables, then we stir and increase the heat by observing the rawness of the vegetables.

So in the above process, we can conclude, our hand and eyes are acting as (sensor) feedback, our brain is the controller and our hands are the device used to control input(adding vegetables, stirring etc)

Let’s take examples of open-loop and closed-loop Control Systems ( no need to get afraid of these alien terms, just remember that in any open-loop system as the name suggest, no feedback present whereas in close loop output is related to input via a feedback mechanism, this will be covered in my next post)

Open loop Control System examples !!

1. There are so many open-loop systems that are present around us, so let me explain this with the help of a realistic example. Consider that , I bought one product from a nearby local store, then the product was found defective by me , so finally I lodged a complaint with the consumer forum department.

Then again I bought some other item from the same store, again it was defective, and again I complained in consumer forum. This process goes on many times….(with no action being taken by consumer forum against the store).

So this is one of the examples of open-loop system where consumer forum authorities don’t give any heed towards my complaints(feedback) and the output(of supplying defective products) is independent of the input(of going again and again to same-store for buying any product)

On a serious note:

Washing machine (or clothes dryer) is a good example of an open-loop system where the cleaning action happens for a certain time that is specified by the user, either way, the washing machine (or dryer) shuts off after the time it up.

It has no way of knowing if the clothes are dry or not and then the machine stops working, it doesn’t pay any heed to the quality of the cleaning (or drying in case of a dryer).

Like this there are many other examples of open loop systems present like gas stove, fan, heater, cooker , toaster etc.

Now, let’s take examples of closed loop systems in the next section . 

Examples Of Closed Loop Systems !!

From the same examples that we have seen above for the open-loop systems , we will further try my best to explain you the closed-loop system examples now.

So now consider the consumer forum story again , now imagine that the same consumer forum has taken adequate measures against the faulty store.

So we can say that output(of supplying defective products) and the input(of going again and again to the same-store for buying the defective product) is effected by the feedback mechanism (complaints). So this is an example of closed-loop system.

Now again consider the example of the traditional dryer, Some modern dryers nowadays includes a humidity sensor in the air output of the dryer.

This tells the dryer to shut off when the air coming out of the dryer begins to be very dry thus, “Closing the loop” of the feedback system.

So in nutshell, if the output is related to input by the virtue of some feedback mechanism, then the system is closed loop system, otherwise an open loop system.