93.1.8. Numerical Examples

So, we do have some interesting numerical examples also to have seen starting example it is a voltage amplifier, we do have a voltage amplifier here. So, this is the forward amplifier and the feedback along with its feedback connection of course, the feedback it is shunt here and series here; that means, voltage-series feedback connection.

This chunk introduces a numerical example related to a voltage amplifier. The term 'voltage-series feedback connection' indicates that the feedback circuit is designed to enhance the voltage gain of the amplifier by taking some output voltage and feeding it back into the input. This process can improve linearity and stability in the amplifier's performance.

Imagine you have a microphone (the voltage amplifier) that needs to be amplified to reach an audience. The speaker hears the amplified sound (output), but to keep it clear and stable, a portion of that sound is sent back to the microphone for adjustments. This is essentially what feedback does in our numerical example.

The given parameters are here, input resistance it is 1 k, output resistance it is 4 k, A the gain of the forward amplifier in ideal condition it is 200. On the other hand for the feedback circuit the β = 0.095 of course, this is converting voltage to voltage. So, it is unit less.

This chunk presents important parameters for the voltage amplifier example. The input and output resistances (1 kΩ and 4 kΩ, respectively) are crucial for understanding how the amplifier interacts with the circuit it is part of. The gain 'A' represents how much the input voltage is amplified (200 times in this case), which is significant for how much louder a sound might be. The feedback factor 'β' (0.095) shows the fraction of output voltage fed back to the input, which is essential for understanding how feedback affects performance.

Think of a garden hose attached to a water source. Here, the input resistance represents how easily water enters the hose, and the output resistance is how easily it can leave the hose into the garden. The gain reflects how much pressure the water builds up as it passes through. The feedback factor is like a valve that controls how much of the water flowing out is redirected back into the hose to maintain pressure.

We need to find the value of the voltage gain from the primary input to the primary output defined as denoted by A and defined by . So, we need to find what will be this ratio.

In this chunk, we are tasked with calculating the actual voltage gain, represented by A. To find this, we typically use the formula that combines the amplifier's gain and the feedback factor. The effective voltage gain reflects how much the output voltage compares to the input voltage.

If we think of the voltage gain like a performance enhancement in a concert, it signifies how the sound intensity (voltage output) compares to the original sound (input). Just as a singer's voice can be amplified many times louder than when sung alone, the voltage gain in an amplifier indicates how much more powerful the output is compared to the input.

Case-I; when you consider feedback network it is ideal one and case-II where feedback network it is having finite input resistance and also it is having finite output resistance.

This chunk outlines two scenarios for analyzing the voltage amplifier. In Case I, we assume an ideal feedback network where both the input and output resistances of the feedback network are infinite, meaning they do not affect the amplifier's performance. This ideal scenario is a simplified version to understand how feedback influences gain without real-world limitations. Case II introduces non-ideality, where finite resistances begin to influence performance, and this is crucial for deeper analysis.

Consider a perfect echo in a large auditorium (ideal feedback scenario), where sound reflects without any loss. In case II, imagine that some sound gets absorbed by the walls (finite resistances), and the echo starts to fade. Understanding both scenarios helps us appreciate how ideal designs differ from practical applications.

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