1.3.1. Analog Circuits

Whenever we say electronic circuit what we are looking for it is that, if I look into the circuit as a black box. So, if I say that this is my electronic circuit, to make this circuit working what I need to do it is we need to put the power on. So, we can give a DC supply to activate the circuit. So, let you think of that, this is a power supply by which we are energizing the circuit.

An electronic circuit is essentially a pathway that allows electrical current to flow. To make an electronic circuit work, you first need to power it on by supplying a direct current (DC). This power energizes the circuit, enabling it to perform its intended function. Think of the circuit as a black box: it needs energy (power) to operate and perform tasks like amplifying signals or processing data.

Imagine your smartphone. Just like an electronic circuit, your phone requires a battery (power supply) to function. When you turn on your phone, you're essentially powering on the internal electronic circuits that allow it to run apps, connect to the internet, and perform tasks.

Once it is getting energized then you can apply the signal at the input port. And then you can consider the corresponding effect at the output, namely you would like to see what will be the corresponding output coming to this circuit.

After powering the circuit, we can then apply input signals, which serve as the stimulus for the circuit. These input signals could be any form of electrical signals (e.g., voltage or current). The circuit processes these signals and produces output signals, which we can measure or observe. This input-output relationship is a fundamental concept in electronics, as it describes how circuits transform input energy into useful output.

Think about a blender. You plug it in (power it), add fruits and liquids (input), and then when you turn it on, it blends everything into a smoothie (output). Just as the blender processes the ingredients and gives you a final product, electronic circuits process electrical signals to produce an output.

Whenever we say a types of signals, we are assuming signal means it is voltage changing with time... depending on the emphasis and the allowable levels of the signal, the signal can be different types; namely analog and digital kind of signal.

In electronics, signals can generally be categorized into two main types: analog and digital. An analog signal can continuously vary in voltage levels, providing a smooth representation of data. In contrast, digital signals have distinct levels (usually represented as binary digits 0s and 1s) and can only take on specific values. The type of signal determines how the circuit operates and how information is processed and transmitted.

Consider a dimmer switch for your light bulb. When you turn the knob, the brightness changes smoothly (analog signal). Now think of a light switch that can only be on or off (digital signal). The dimmer represents an analog signal, while the switch represents a digital signal; both control the light but in different ways.

In case if you are having such kind of distinct levels, need not be only two, but it is having finite levels then we call it is digital signal... we call analog signal here and these signals whatever the signals we have discussed here, here as well as here they are digital signals.

Analog signals vary continuously and can take on any value within a range, making them very versatile for representing real-world phenomena like sound or temperature. Digital signals, however, are limited to discrete values. This distinction is crucial because it affects how circuits process information. Analog signals can represent a wider range of data, while digital signals are easier to store and manipulate using modern technology.

To illustrate, imagine listening to music on vinyl records (analog) versus streaming the same music as digital files. The vinyl captures a continuous wave of sound, while digital streaming breaks the sound into discrete samples. Both have their advantages, but the digital format allows for easier distribution and manipulation.

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