91.5.1. Voltage Sampling and Current Mixing

So, here we do have so, this is the basic model and here is the corresponding detailed model. In this case as I said that the input signal and output signal are say voltages. So, here we consider it is voltage here also it is voltage, so the signal here it is voltage and this is also voltage.

This chunk introduces the fundamental idea that both the input and output signals in this model are voltages. This is important because it establishes the context in which the sampling and mixing of voltages will occur. Understanding whether a signal is voltage or current is critical when designing circuits, as it determines how signals are processed and how components connect.

Think of this setup like two people communicating using walkie-talkies. Both must use the same system (like signals voltage) for effective communication. If one person is talking in a different language (like using current instead of voltage), they won't be able to understand each other.

Now, since here the signal it is voltage as you can see that the sampler whenever we are sampling the signal, it should be parallel connection. So, we do have this is the output signal in fact, that is S to sense this voltage the input port of the feedback network it should be parallelly connected.

This segment explains the necessity of a parallel connection for the voltage sampler. When sampling a voltage, the output voltage signal is taken from a point that does not disturb the overall current flow in the circuit. This is similar to taking a small sip from a full glass of water without spilling the entire contents.

Imagine you are trying to gather information from a group of friends without interrupting their conversation. If you stand close and just listen in (parallel), you get the information without altering their discussion much, unlike if you were to physically take someone out of the conversation (series connection).

On the other hand if you see signal here they are voltages, so our intention is to use these two voltages to generate this S or v. So, this signal and this signal we are mixing together to generate a voltage here which is if you see here if you consider this loop. So, if I say that this is v this is + and this is ‒.

Here, the mixing of the voltage signals is discussed. The two voltage sources are connected in series to create a new signal. This is essential for generating feedback signals that influence the system's operation, essentially controlling how the circuit processes the input signals.

Think of this like adding two flavors of ice cream together to create a new flavor. Each original flavor (voltage source) combines to influence the final taste (output signal), which is a mixture of the two.

In this ideal model while you are say tapping or sampling the signal from the output port we assume that there is no loading effect. Same thing here also we are assuming it is loading effect. To create that situation we have considered this ideal situation namely the resistance here it is ∞.

In this part, the 'ideal' conditions are described, emphasizing that both the input and output points should not load or affect the system’s performance. An infinite resistance implies no current will flow through it, ensuring that the voltage remains unaffected by the feedback path.

This is like trying to listen to music through headphones without them affecting the sound quality. An ideal condition would be not drawing any power from the music source when you’re connected; similarly, we want our nodes in the circuit to not disturb the original signals.

So, we may say that this is βv. So, whatever the desired equation we are expecting? Namely v it will be βv that we obtain and here we got v = v ‒ v.

This section defines the feedback in the system. The feedback signal can be represented by β, where the output signal is a scaled version of the input signal, thereby demonstrating how feedback adjusts signal processing within this voltage configuration.

Imagine using a thermostat. The thermostat senses room temperature (input), sends a signal to a heater, which adjusts its power accordingly (feedback) to maintain a comfortable atmosphere. The value of β determines how responsive or 'sensitive' the heater is to changes in temperature.

So, in summary this configuration typically or most of the time we refer as shunt series feedback. So, this is shunt and this is where series; shunt-series feedback or you may say that this is voltage and then series feedback.

In this final part of the chunk, the feedback configuration is named based on its connections—'shunt' for the parallel sampling and 'series' for mixing. This terminology helps in categorizing the system for analysis and design, ensuring engineers know the expected behavior of the circuit.

Consider different types of bus routes in a city. A ‘shunt route’ might pick up passengers at several points along the way (parallel sampling), and a ‘series route’ would take them directly from point A to point B. Similarly, understanding whether a configuration is shunt or series helps engineers predict how the circuit behaves.

--