Electronic Systems

Electronic systems are a physical interconnection of components or parts that collect various amounts of information.

It does this with the help of input devices, such as sensors that respond to this information in some way and then use electrical energy in the form of an output action to control a physical process or perform some kind of mathematical operation on the signal.

However, electronic control systems can also be considered as a process that converts one signal into another to respond to the desired system.Then we can say that a simple electronic system consists of an input, a process and the input variable to the system, and the output variable from the system consists of an output, both of which are signals.

There are many ways to represent a system, for example: mathematically, descriptively, illustrated or schematically.Electronic systems are often represented schematically as a series of interconnected blocks and signals, in which each block has its own input and output set.

As a result, even the most complex electronic control systems can be represented by a combination of simple blocks, each block contains or represents a separate component or complete subsystem.The representation of an electronic system or process control system as interconnected blocks or boxes is commonly known as "block diagram representation".

electronic systems
Representation of Electronic Systems as Block Schema

Electronic systemsare the whole of both input and output waves* and processes that affect inputs.In addition, input signal/signals may cause the process to change or the operation of the system to change.Therefore, while input(s) into a system is the "cause" of the change, the resulting action that occurs in the system output due to the presence of this reason is called "effect", and the effect is a result of the cause.

In other words, an electronic system can be classified as "causal" by nature, as there is a direct relationship between its input and its output.Electronic system analysis and process control theory are usually based on this Cause and Effect analysis.

For example, in an audio system, a microphone (input device) causes sound waves to be converted into electrical signals for amplifier amplification (a process) and generates sound waves as an effect of being driven by a speaker (output device).

However, an electronic system does not have to be a simple or single operation.There may also be interconnection of several subsystems that work together within the same public system.

Our audio system may include, for example, the connection of a CD player or a DVD player, an MP3 player or a radio receiver, all of which have multiple inputs to the same amplifier and run one or more stereo or home theater types in turn.

But an electronic system can not only be a sum of inputs and outputs, it only needs to "do something", even if it is to monitor a key or "TURN on" a light. We know that sensors areinput devices that detect real-world measurements or convert them into electronic signals that can be processed later.These electrical signals can be in the form of voltage or current within a circuit.The opposite or output device is called an actuator, which usually converts the processed signal into a process or action in the form of mechanical motion.

Electronic Systems

Electronic systemsoperate on continuous time (CT) signals or discrete time (DT) signals.A continuous-time system is a system in which input signals are defined over a period of time, such as an analog signal that "continues" over time by generating a continuous-time signal.

However, a continuously timed signal can also vary in size or be inherently periodic with a T time period.As a result, continuously timed electronic systems tend to be fully analogue systems that produce a linear process with both input and output signals referenced for a certain period of time.

electronic systems

For example, the temperature of a room can be classified as a continuous time signal that can be measured from cold to heat or between two values or setting points from Monday to Friday. We can represent a continuous time signal using the argument for t time, where x(t) represents the input signal and y(t) represents the output signal in the time period.

In general, most of the signals found in the physical world that we can use tend to be continuously timed signals.For example, voltage, current, temperature, pressure, speed, etc.

On the other hand, a discrete-time system is a system in which input signals are not continuous, but have an array or a series of signal values defined at "discrete" time points.This usually results in a discrete timed output, represented as a series of values or numbers.

Typically, a discrete signal is specified only at discrete intervals, values, or evenly spaced points over time.For example, the temperature of a room was measured at 13:00, 14:00, 15:00 and again at 16:00, regardless of the actual room temperature between these points.

electronic systems

However, a continuous time signal, x(t), can only be represented as a separate set of signals at discrete intervals or "moments in time".Discrete signals are not measured against time, but instead drawn at discrete time intervals, where n is the sampling interval.As a result, discrete time signals are usually shown as x(n) representing input and y(n) representing output.

Next, we can represent the input and output signals of a system in x and y, respectively, with the signal, or with signals themselves , usually representing the time for a continuous system, and the n variable representing an integer value.

electronic systems
Continuous-time and Discrete-time System

Interconnection of Electronic Systems

One of the practical aspects of electronic systems and block diagram representation is that they can be combined in series or parallel combinations to create much larger systems.Many large real systems are built using the interconnection of several subsystems, and using block diagrams to represent each subsystem, we can create a graphical representation of the entire analyzed system.

When subsystems are combined to create a series of circuits, the total output in y(t) will be equivalent to the product of input signal x(t), as shown gradually together by subsystems.

SerialLy Connected Electronic Systems

electronic systems

For a continuously connected system connected to the series, the output signal of the first subsystem is y(t), "A" becomes the input signal of the second subsystem, the output continues throughout the series chain, which gives the input of the third subsystem " B", "C" and A x B x C, etc.

Then the original input signal is cascaded through a serially connected system, so the equivalent single output for two series-connected subsystems will be equal to the product of the systems, that is, y(t) = G 1 (s) x G 2 ( s).Where G represents the transfer function of the subsysize.

Note that the term "Transfer Function" of a system is defined as the mathematical relationship between the system entry and its output or output/input, and therefore defines the behavior of the system.

Also, for a system that is connected in an array, it is not important in relation to input and output signals as the sequence in which a series of operations are performed; G 1 x (s') is the same as G 2 (s) x G 1 (s).An example of a simple series of connected circuits can be an amplifier, followed by a single microphone that feeds a speaker.

Parallel Connected Electronic Systems

electronic systems

For a parallel connected continuous-time system, each subsystem receives the same input signal, and their individual outputs are aggregated to produce a generic output, y(t).Then, for two parallel connected subsystems, the equivalent single output will be the sum of two separate inputs, that is, y(t) = G 1 (s) + G 2 (s).

An example of a simple parallel connected circuit can be an amplifier and several microphones that feed into a mixer, that is, a mixer that feeds the speaker system.

Electronic Feedback Systems

Another important interconnection of systems widely used in control systems is the "feedback configuration".In feedback systems, part of the output signal is "fed back" and added or removed from the original input signal.The result is that the output of the system continuously changes or updates its input to change the response of a system to improve stability.A feedback system, as shown, is also commonly referred to as the "Closed Loop System".

Closed Loop Feedback System

electronic systems

Feedback systems are widely used in most practical electronic system designs to help stabilize and increase control of the system.If the feedback loop reduces the value of the original signal, the feedback loop is known as "negative feedback".If the feedback loop is added to the value of the original signal, the feedback loop is known as "positive feedback".

An example of a simple feedback system can be a thermostatically controlled heating system in the house.If the house is too hot, the feedback loop will put the heating system in the "OFF" position to make it cooler.If the house is too cold, the feedback loop "TURNS ON" to make the heating system warmer.In this case, the system consists of the heating system, air temperature and thermostatically controlled feedback loop.

Transfer Function of Systems

electronic systems

Any subsystem can be represented as a simple block with an input and output, as shown.In general, the input is determined as follows: εi and output: εo .The ratio of output to input represents the gain ( G) of the subsysordial and is therefore defined as: G = εo/εi

In this case, G represents the Transfer Function of the system or subsysize.When discussing electronic systems in terms of transfer functions, the complex operator uses s, then the gain equation is rewritten as follows: G(s) = εo(s)/εi(s)


We found that a simple Electronic System consists of an input, a process, an output, and possibly feedback.Electronic systems can be represented using interconnected block diagrams, where the lines between each block or subsystem represent both the flow and direction of a signal throughout the system.

Block diagrams do not need to represent a single simple system, but they can represent very complex systems consisting of many interconnected subsystems.These subsystems can be connected in series, parallels or combinations of both, depending on the flow of signals.

We found that electronic signals and systems can be inherently continuous or discretely timed, and can be analogue, digital or both.Feedback loops can be used to improve or decrease the performance of a particular system by providing better stability and control.Control is the process of ensuring that a system variable meets a specific value called a reference value.