Electrical component

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In electrical engineering, an electrical component is an essential part of an electrical circuit that cannot be physically subdivided further without losing its function. The term stands for

  • a carrier of a physical or electronically realizable property, also in the form of an idealized component,
  • a real (discrete) component.

The electrical component can be composed of components,

Example: coil body + wire + core = coil, with the electrical property inductance .

Important electrical components are voltage source , resistor , capacitor , coil , diode , transistor and integrated circuit .

Basic types of components are symbolized in circuit diagrams by standardized circuit symbols .

In general usage, especially in the industrial sector, real (discrete and integrated) electrical components, electromechanical and mechanical components, and electronic components are also called. This classifies components that are suitable for electronic devices and systems and that are industrially manufactured, sold and used.

Various electrical components; Click on the picture (and if necessary further details) leads to the picture description page with details on the individual components shown


Electrical components can be divided according to various independent aspects:

Ideal and real components

Ideal components are fictitious components with idealized properties. They are the basis for every theoretical and mathematical treatment and for circuit simulation .

Real components are physical implementations of components. Mechanically, they form a unit and, from an electrical point of view, can also be composed of several components, i.e. represent a circuit themselves (e.g. integrated circuit or a spark extinguishing combination ). If necessary, a real component is represented by the model of an equivalent circuit diagram made up of ideal electrical components.

Example: A coil is not an ideal component that only has the property of an inductance, but the ohmic wire resistance and parasitic capacitances must also be taken into account.

Active and passive components

Active components can output a signal with a higher power than the source of the recorded signal can provide, or they allow control (for example thyristors , optocouplers , relays ). To do this, they draw auxiliary energy from an additional supply or generate electrical energy themselves ( electrical energy sources , e.g. solar cells , thermocouples ). In addition, semiconductor components that only modify signals, such as diodes, are also included in some of the active components.

Passive components are those that have no amplifier effect and have no control function, such as resistors, capacitors, inductors, resonators and memristors . They can have linear or non-linear electrical properties.

Linear and non-linear components

Under specified application conditions, linear components have a linear relationship between certain electrical quantities (often electrical current strength and electrical voltage ); thus they do not generate any distortion . When operating with alternating variables, this has the effect, for example, that no other frequencies occur in the output signal than in the input signal. They satisfy the superposition principle .

Nonlinear components can have an undesirable or a completely desirable nonlinearity.

Example: A diode only conducts current in one direction, while with the opposite polarity of the applied voltage it behaves almost like an insulator.
Example: The simulation of sensory perceptions often requires components for a logarithmic relationship.

Discrete and integrated components

An electrical component that only consists of a single functional unit is called discrete . In contrast, in integrated circuits, for example, several identical or different functional units are combined to form a complex component.

Example: A transistor can occur both as a discrete component and as part of an integrated circuit.

Analog and digital components

These include the components for treatment

as well as the transition elements as

Operating principles

Electrical components use effects triggered by an electric or magnetic field , as well as thermal or photoelectric effects , solid-state physical properties of semiconductor materials and other influenceability as well as mechanical movements and forces in order to create certain desired functional relationships, see also sensors based on the measuring principle . Components are used to convert electrical quantities with one another (for example, current intensity into voltage or their temporal derivation) as well as from non-electrical into electrical quantities (for example light, sound, magnetic flux density, force, temperature, see also sensors according to measured quantity ) and vice versa. Examples are photodiodes , light emitting diodes , signal transmitters , actuators and sensors such as mechanical or electronic switches , thermistors , piezo elements or strain gauges .

The interconnection of components and electrical lines results in an electrical circuit, often mounted on a printed circuit board or as an assembly . The internal circuit and function of such pluggable or solderable circuits are often not shown in detail, but only specified on the basis of their type designation.


  • Erwin Böhmer, Dietmar Ehrhardt, Wolfgang Oberschelp: Elements of applied electronics: Compendium for training and work . 16th edition. Vieweg + Teubner, 2010, ISBN 978-3-8348-9336-9 .

List of electrical components

Web links

Individual evidence

  1. IEC 60050, see DKE German Commission for Electrical, Electronic and Information Technologies in DIN and VDE: International Electrotechnical Dictionary entry 151-11-21.