Electrical courses are beneficial

Electric circuit

Under a Circuit one understands a connection between different components that enable a charge transport. In the simplest case, a circuit consists of an electrical energy source, an electrical consumer and electrical lines that connect them.

Simple circuit (open)


Normally, however, an electrical circuit contains a large number of generators, consumers as well as parallel and series connections. In the next clip you can see a matching motherboard with capacitors and resistors:

Video: Electrical Circuit

Since it is difficult to realistically represent complex circuits like in the clip, a more abstract type of representation is used in plans instead of detailed images: the circuit diagram.

Circuit diagram / circuit diagram and circuit symbols

The circuit diagram has the advantage that all relevant components of the circuit are simply represented by uniform symbols and characters as Circuit symbols can be mapped. In this and the following chapters, circuits are shown almost exclusively in the form of circuit diagrams.

A circuit diagram can be used to read:

  • What kind of components are installed,
  • which electrical parameters they have and
  • in what way they are related to each other.

The circuit symbols for the circuit diagrams are standardized in [ding] and [dinh]. Since there is a very large number of components, only a small selection is shown here. New components appearing in the following chapters are then explained at the relevant point.


Closed and open circuit

If there is an electric current, one speaks of a closedCircuit. On the other hand, a circuit in which not all elements are sufficiently connected is called interruptedCircuit designated. If a switch is integrated in the circuit, it fulfills the criteria of the closed and the interrupted circuit, depending on the position of the switch.

Circuit diagram of a closed and an open circuit