Linear system - definition

A linear system is a physical or mathematical system whose behaviour can be described by linear equations satisfying the principle of superposition. This means that the response of the system to the sum of several input signals is equal to the sum of the responses to each of these signals individually, and that the response to an input signal with amplitude multiplied by a constant is also multiplied by the same constant. In electronics and control theory linear systems are the fundamental model for the analysis and design of dynamic systems.

In the context of electrical systems, a linear system consists of passive and active elements such as resistors, capacitors and amplifiers that operate in the linear range, i.e. without non-linear distortion. The current-voltage characteristics of these elements must be linear, which means proportionality between electrical quantities. Tools of classical analysis such as the Laplace operator method, transition functions, impulse responses or Fourier transforms can be used for such circuits.

Linear systems exhibit predictable behaviour that allows accurate modelling, simulation and the design of filtering, amplifying, integrating or differentiating circuits. In practice, however, every real device has its own linearity limitations - arising, e.g., from saturation, operating voltage range or material properties - so the concept of a linear system mainly refers to operation within a certain parameter range, where non-linearities are negligible or negligible.

In control systems and Automation linear systems are most often described by linear differential equations with constant coefficients. This allows extensive stability theory, step response, state space and the design of regulators based on classical or modern engineering methods.

Transfer Multisort Elektronik (TME) is one of the world’s largest global distributors of electronic components, electrotechnical parts, workshop equipment, and industrial automation. The catalog includes over 1,500,000 products from 1,300 leading manufacturers. TME’s modern logistics centers in Łódź and Rzgów (Poland), with a combined area of over 40,000 m², ship nearly 6,000 packages daily to customers in more than 150 countries.

TME also invests in the development of knowledge and skills of young engineers and electronics enthusiasts through the TME Education project, and supports the tech community by organizing the TechMasterEvent series, promoting innovation and experience exchange.