Problem with Electronic Feedback?

In summary, the conversation discusses the differences between positive and negative feedback on an inverting and non-inverting op-amp in the context of analogue electronics. The individual is curious about how the use of positive feedback affects the formula for finding the voltage output of the op-amp. It is noted that positive feedback is rarely used, with the most common application being for a comparator. Additionally, oscillators can also be created using positive feedback.
  • #1
gunblaze
187
0
Hi, i was reading through the topic on analogue electronics. And every single example on my text seems to just be just on the negative feedback on both the inverting and non-inverting input of an op-amp. What i would like to know is what's the difference between positive and negative feedback on an inverting and non-inverting op-amp. Will there be any changes in the formula to find the Voltage ouput of the op-amp?
 
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  • #2
You can't use positive feedback on inverting and non-inverting amplifiers. Positive feedback is hardly ever used, but the most common use of it would be for a comparator. When the non-inverting input is at a higher voltage than the inverting input, the op amp will be positively saturated and put out the positive supply voltage. When the non-inverting input drops below the inverting input, the op-amp hits the other (negative) rail. Also, oscillators can be made with positive feedback.
 
  • #3


Hello,

Thank you for your question. It is understandable that you are confused about the use of positive and negative feedback in op-amps. Let me try to clarify this for you.

Feedback is an essential concept in electronics, whether it is in analog or digital circuits. It refers to the process of taking a portion of the output signal and feeding it back to the input of the circuit. This feedback can be either positive or negative, depending on the polarity of the signal being fed back.

In the case of op-amps, negative feedback is the most commonly used type. It is achieved by connecting a resistor between the output and the inverting input of the op-amp. This type of feedback is used to stabilize the output of the op-amp and reduce distortion in the circuit. It also helps in increasing the gain and bandwidth of the op-amp.

On the other hand, positive feedback is when the feedback signal is in phase with the input signal. This type of feedback is not commonly used in op-amps because it can lead to instability and oscillations in the circuit. Positive feedback can be achieved by connecting a resistor between the output and the non-inverting input of the op-amp.

In terms of the formula to find the voltage output of an op-amp, it will not change whether you are using positive or negative feedback. The formula for the voltage output is still Vout = A*(V+ - V-), where A is the open-loop gain of the op-amp and V+ and V- are the voltages at the non-inverting and inverting inputs, respectively.

I hope this explanation helps to clear your confusion about positive and negative feedback in op-amps. If you have any further questions, please feel free to ask. Thank you.
 

1. What is electronic feedback?

Electronic feedback is a process by which information about the output of a system is fed back into the input, in order to modify the behavior of the system. In other words, it is a way for a system to self-regulate and make adjustments based on its own performance.

2. How does electronic feedback work?

Electronic feedback involves using sensors or detectors to measure the output of a system, and then using that information to adjust the input. This can be done through various methods, such as changing the voltage, current, or frequency of the input signal.

3. What are some common problems with electronic feedback?

Some common problems with electronic feedback include instability, oscillation, and noise. These issues can arise if the feedback loop is not properly designed or if there are external factors that interfere with the system.

4. How can problems with electronic feedback be prevented?

To prevent problems with electronic feedback, it is important to carefully design the feedback loop and ensure that it is stable. This can involve using filters to reduce noise, selecting appropriate values for components, and testing the system under different conditions.

5. What are some real-world applications of electronic feedback?

Electronic feedback is used in a wide range of applications, including control systems for industrial processes, electronic circuits, and robotics. It is also used in medical devices, such as pacemakers, to monitor and regulate bodily functions.

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