Sähköfunktion

Sähköfunktion is a Finnish term that translates roughly to "electric function." In scholarly and technical contexts it is used as a generic label for a mathematical function that describes an electrical quantity, such as voltage, current, electric potential, or impedance, as a function of time, space, or frequency. The phrase does not denote a single standardized object, but rather a family of functions encountered in electrical engineering, physics, and related fields. In this sense, sähköfunktion can refer to both fundamental quantities in electrostatics and the various response or transfer functions used to model circuits.

In electrical engineering, a common usage is to refer to transfer functions that relate an input signal to an output signal. For a linear time-invariant system, the relationship is often written in the Laplace domain as Y(s) = H(s)X(s), where H(s) is the transfer function. Electromagnetic impedance can likewise be described as a function Z(s) or Z(jω) depending on the analysis framework. Thus, sähköfunktion encompasses these response functions as well as other circuit descriptors.

In physics, electric potential is another representative example. The electric potential φ(x) is a scalar function whose negative gradient yields the electric field, E = −∇φ. Green’s functions and fundamental solutions are used to construct φ for given charge distributions, illustrating how a spatially dependent electric function encodes electrostatic interactions.

The term serves as a descriptive label rather than a fixed technical entity, covering voltage, current, impedance, potential, and their time-, space-, and frequency-domain representations within electrical phenomena.