Positive Feedback

The input signal is the sum of the actual signal, and the feedback signal is known as positive feedback. The above figure shows the circuit diagram for positive feedback. The positive feedback can be used to amplify system responses. The major drawback of this positive feedback is its instability. These can be used less in traditional control systems as compared to negative feedback. Positive feedback can actually add the feedback to its input, whereas negative feedback subtracts. For example, we can find positive feedback in a microphone and speaker system. The microphone picks up sound, amplifies it through the speakers, and captures it again. Here, it creates a loop, increasing amplification.

The Transfer Function of Positive FeedBack can be Written as:

[Tex]TF=\frac{G}{1-GH} [/Tex]

Advantages of Positive Feedback

• Positive feedback is mainly used for amplification. Positive feedback can amplify weak signals.
• Positive feedback is well-used in non-linear systems such as oscillators or amplifiers.
• In applications where quicker responses to changes in input are needed, we use positive feedback.

Disadvantages of Positive Feedback

• It is very difficult to control and regulate a system with positive feedback.
• The amplification effect of positive feedback can result in unstable system behaviour or even system failure.
• It is very challenging to maintain system stability.

Applications of Positive Feedback

• Positive feedback can be used in regenerative amplifiers to increase the amplitude of signals.
• Positive feedback can be used in oscillators to produce oscillations and in electronic circuits.
• These can be used in biological processes during a child’s birth; they can intensify the labour process.
• This can be used in robotics and automation.
• Positive feedback can also be used to control the audio systems.

The control system is an important component in engineering and technology. It involves many different mechanisms to improve or regulate the systems. The primary goal of the control system is to manage the input to get the desired output from the system. There are two types of control systems: open-loop control systems and closed-loop control systems. The open-loop control system can operate without any feedback, but the closed-loop control system can operate with the output of the system sent to its input as feedback. Feedback is an important concept in control systems; it plays a major role in different factors by providing accuracy, and stability, and improving the performance of various engineering and technical applications. It uses the output of the system to perform its operations by creating a closed loop. In control systems, positive feedback and negative feedback are mechanisms that influence the system’s behavior.

In this article, we will be going through the Differences between Positive Feedback and Negative Feedback, First, we will see what is Feedback, Then we will go into brief about Positive Feedback and Negative Feedback, Then we will go through the Difference between positive and Negative Feedback in the Tabular Form, At last, we will conclude our Article with Some FAQs.