A physical link of devices that impacts the behavior of other devices or systems is referred to as an electrical control system. An ordinary electronic system is built up with an input, a process, and also output. Both input and output variables in the system are signals. A basic electronic system consists of an input, a process, and an output. Circulation pumps, compressors, construction systems, refrigeration plants, and motor control panels are examples of such systems. In other words, an electronic system is “causal” in the sense that there is a strong correlation between its inputs and outputs. Electronic systems analysis and process control principles are typically based on a cause-and-effect analysis.
Electronic systems are typically depicted by electronics manufacturers as a network of interconnected blocks and signals. Each block has its own set of inputs and outputs. This is known as a block-diagram representation. An electrical system, on the other hand, cannot just be a collection of inputs and outputs; it must have a purpose to “do” something, even if that something is as basic as monitoring a switch or “turning on” a specific light. We know that sensors are input devices that detect or transform real-world measurements into electronic signals that can then be processed. The opposite or output device is called an actuator, which converts the processed signal into some operation or action, usually in the form of mechanical motion.
Difference between CT and DT:
A CT system is one where the input signals are continuous over time. These are analog systems that produce a linear operation with referenced input and output signals over a specified time period, such as between 13:00 and 14:00. A DT system has an input signal that is a sequence or series of signal values defined in multiple time points, such as 13:00 and 14:00. A steady signal, on the other hand, can vary in magnitude or be constant with a timeframe. In conclusion, constant-time controlled systems, for example, electronic systems, are entirely analog systems capable of producing a linear operation with both their input and output signals over a specified period of time.
Types of Control Systems:
Control systems are classified into two types: open-loop systems and closed-loop systems.
Open–Loop Control System:
An open-loop control system is one in which the output does not give feedback to the input for correct changes. Instead, the output differs from the individual inputs. This means that external conditions will have no effect on the system output. An example is a timer-controlled central heating boiler which is switched between certain preset times regardless of the thermal comfort level of the building. The advantages of open-loop systems are that they are simple, easy to manufacture, and generally stable. However, they can be inaccurate and unreliable as the outputs are not automatically corrected.
Closed-Loop Control System:
A closed-loop control system is defined as one in which the output sources influence the input sources in order to maintain the output value. This is established through the use of a loop called a feedback loop. For example, boilers may have a temperature thermostat that monitors a building’s thermal comfort level and sends a feedback signal to ensure that the controller maintains the set temperature. Closed-loop systems have the advantage of being precise and can be made more or less sensitive depending on the required stability of the system and custom electronics products.
Systems such as feedback systems are utilized a lot in practical electronic systems and their designs which ultimately help them to stabilize the system and enhance its control. If the feedback loop decreases the quality of the original signal, it is termed “negative feedback”. If the feedback loop adds to the value of the original signal, the feedback loop is referred to as “positive feedback.”
Parallel connected electronic system:
For parallel connected continuous-time systems, each subsystem receives the same input signal, and their individual outputs are added together to produce a composite output, y(t). The comparable single output for two parallel linked subsystems will thus be the sum of the two distinct inputs, y(t) = G1(s) + G2(s) (s). A basic parallel linked circuit can have many microphones flowing into a mixing console, which then feeds an amplifier and speaker system.
Electronic system control summary:
We have seen that an ordinary electronic control system has an input, a process, an output, and maybe at some point possibly feedback. Just like in PCB design, interconnected block diagrams can be used to represent electronic systems, with the lines connecting each block or subsystem representing both the flow and direction of the signal through the system. Block diagrams do not need to represent a simple single system but can represent very complex systems composed of many interconnected sub-systems.