Electrical network
For electrical power transmission grids and distribution networks,
see Electrical grid.
A simple electric circuit made up of a voltage source and a resistor. Here, , according to Ohm's law.
An electrical network is an interconnection of electrical
components (e.g., batteries, resistors, inductors, capacitors, switches, transist
ors) or a model of such an interconnection, consisting of electrical
elements (e.g., voltage sources, current
sources, resistances, inductances, capacitances). An electrical circuit is a
network consisting of a closed loop, giving a return path for the
current. Linear electrical networks, a special type consisting only of sources
(voltage or current), linear lumped elements (resistors, capacitors, inductors),
and linear distributed elements (transmission lines), have the property that
signals are linearly superimposable. They are thus more easily analyzed, using
powerful frequency domain methods such as Laplace transforms, to
determine DC response, AC response, and transient response.
A resistive circuit is a circuit containing only resistors and ideal current and
voltage sources. Analysis of resistive circuits is less complicated than
analysis of circuits containing capacitors and inductors. If the sources are
constant (DC) sources, the result is a DC circuit. The effective resistance and
current distribution properties of arbitrary resistor networks can be modeled in
terms of their graph measures and geometrical properties. [1]
A network that contains active electronic components is known as
an electronic circuit. Such networks are generally nonlinear and require more
complex design and analysis tools.
Classification[edit]
By passivity[edit]
An active network contains at least one voltage source or current source that
can supply energy to the network indefinitely. A passive network does not
contain an active source.
, An active network contains one or more sources of electromotive force.
Practical examples of such sources include a battery or a generator. Active
elements can inject power to the circuit, provide power gain, and control the
current flow within the circuit.
Passive networks do not contain any sources of electromotive force. They
consist of passive elements like resistors and capacitors.
By linearity[edit]
A network is linear if its signals obey the principle of superposition; otherwise
it is non-linear. Passive networks are generally taken to be linear, but there are
exceptions. For instance, an inductor with an iron core can be driven
into saturation if driven with a large enough current. In this region, the
behaviour of the inductor is very non-linear.
By lumpiness[edit]
Discrete passive components (resistors, capacitors and inductors) are
called lumped elements because all of their, respectively, resistance,
capacitance and inductance is assumed to be located ("lumped") at one place.
This design philosophy is called the lumped-element model and networks so
designed are called lumped-element circuits. This is the conventional
approach to circuit design. At high enough frequencies, or for long enough
circuits (such as power transmission lines), the lumped assumption no longer
holds because there is a significant fraction of a wavelength across the
component dimensions. A new design model is needed for such cases called
the distributed-element model. Networks designed to this model are
called distributed-element circuits.
A distributed-element circuit that includes some lumped components is called
a semi-lumped design. An example of a semi-lumped circuit is the combline
filter.
Classification of sources[edit]
Sources can be classified as independent sources and dependent sources.
Independent[edit]
An ideal independent source maintains the same voltage or current regardless
of the other elements present in the circuit. Its value is either constant (DC) or
sinusoidal (AC). The strength of voltage or current is not changed by any
variation in the connected network.
Dependent[edit]
For electrical power transmission grids and distribution networks,
see Electrical grid.
A simple electric circuit made up of a voltage source and a resistor. Here, , according to Ohm's law.
An electrical network is an interconnection of electrical
components (e.g., batteries, resistors, inductors, capacitors, switches, transist
ors) or a model of such an interconnection, consisting of electrical
elements (e.g., voltage sources, current
sources, resistances, inductances, capacitances). An electrical circuit is a
network consisting of a closed loop, giving a return path for the
current. Linear electrical networks, a special type consisting only of sources
(voltage or current), linear lumped elements (resistors, capacitors, inductors),
and linear distributed elements (transmission lines), have the property that
signals are linearly superimposable. They are thus more easily analyzed, using
powerful frequency domain methods such as Laplace transforms, to
determine DC response, AC response, and transient response.
A resistive circuit is a circuit containing only resistors and ideal current and
voltage sources. Analysis of resistive circuits is less complicated than
analysis of circuits containing capacitors and inductors. If the sources are
constant (DC) sources, the result is a DC circuit. The effective resistance and
current distribution properties of arbitrary resistor networks can be modeled in
terms of their graph measures and geometrical properties. [1]
A network that contains active electronic components is known as
an electronic circuit. Such networks are generally nonlinear and require more
complex design and analysis tools.
Classification[edit]
By passivity[edit]
An active network contains at least one voltage source or current source that
can supply energy to the network indefinitely. A passive network does not
contain an active source.
, An active network contains one or more sources of electromotive force.
Practical examples of such sources include a battery or a generator. Active
elements can inject power to the circuit, provide power gain, and control the
current flow within the circuit.
Passive networks do not contain any sources of electromotive force. They
consist of passive elements like resistors and capacitors.
By linearity[edit]
A network is linear if its signals obey the principle of superposition; otherwise
it is non-linear. Passive networks are generally taken to be linear, but there are
exceptions. For instance, an inductor with an iron core can be driven
into saturation if driven with a large enough current. In this region, the
behaviour of the inductor is very non-linear.
By lumpiness[edit]
Discrete passive components (resistors, capacitors and inductors) are
called lumped elements because all of their, respectively, resistance,
capacitance and inductance is assumed to be located ("lumped") at one place.
This design philosophy is called the lumped-element model and networks so
designed are called lumped-element circuits. This is the conventional
approach to circuit design. At high enough frequencies, or for long enough
circuits (such as power transmission lines), the lumped assumption no longer
holds because there is a significant fraction of a wavelength across the
component dimensions. A new design model is needed for such cases called
the distributed-element model. Networks designed to this model are
called distributed-element circuits.
A distributed-element circuit that includes some lumped components is called
a semi-lumped design. An example of a semi-lumped circuit is the combline
filter.
Classification of sources[edit]
Sources can be classified as independent sources and dependent sources.
Independent[edit]
An ideal independent source maintains the same voltage or current regardless
of the other elements present in the circuit. Its value is either constant (DC) or
sinusoidal (AC). The strength of voltage or current is not changed by any
variation in the connected network.
Dependent[edit]
