Adaptation (electrical engineering)

Under adjustment between an electrical load and a direct-attached electrical source , the condition will be understood under which a target in view of current , voltage , power or reflectance is achieved. It is also understood to mean an action with which the goal is achieved by inserting a two-port or by dimensioning. In measurement technology , for example , it can be a matter of adapting an electrical signal to the measuring range of a measuring device .

Internal and external resistance of an electrical device with a voltage source

Types of electrical adjustment

Output power of a voltage source as a function of the resistance ratio

{\ displaystyle R _ {\ text {a}} / R _ {\ text {i}}}

The ratio of the linear output impedance (also called internal resistance or source resistance) of the energy-supplying stage to the linear input impedance (also called external resistance or input resistance ) of the following stage is decisive for the type of adaptation . Impedance is used when inductive or capacitive components are involved in a resistance. ${\ displaystyle Z _ {\ text {i}}}$ ${\ displaystyle R _ {\ text {i}}}$ ${\ displaystyle Z _ {\ text {a}}}$ ${\ displaystyle R _ {\ text {a}}}$

Voltage adjustment

If it is significantly smaller than , it is referred to as voltage adjustment, because then a change in the output voltage hardly changes at the connection points. The voltage arriving at the consumer should be maximum in relation to the voltage generated by the source. The output is then also referred to as idling-proof . ${\ displaystyle | Z _ {\ text {i}} |}$ ${\ displaystyle | Z _ {\ text {a}} |}$ ${\ displaystyle | Z _ {\ text {i}} | \ ll | Z _ {\ text {a}} |}$ ${\ displaystyle Z _ {\ text {i}}}$ ${\ displaystyle U}$

Applications: The power grid and the majority of all electrical appliances such as computers, motors. Against destructive overcurrent must fuses are installed.

Current adjustment

At the opposite case, that is of current adjustment speaking, because a change of the output current in the connection line hardly changes. The current intensity arriving at the consumer should be maximum in relation to the current intensity delivered by the source. The output is then also referred to as short-circuit proof . ${\ displaystyle | Z _ {\ text {i}} | \ gg | Z _ {\ text {a}} |}$ ${\ displaystyle Z _ {\ text {a}}}$ ${\ displaystyle I}$

Applications: 20 mA standard signal in automation technology , signal lines in alarm systems .

Power adjustment (active power adjustment)

If ( complex conjugate ), it is power adjustment , specifically to active power sanpassung. The blind portions of and compensate each other. The power arriving at the consumer should be maximum in relation to the power that can be delivered by the source. This is achieved with the restriction that the efficiency with power adjustment is only 50%. Half of the generated power is delivered to the consumer, the other half is converted into heat in the source . ${\ displaystyle Z _ {\ text {i}} = Z _ {\ text {a}} ^ {*}}$ ${\ displaystyle Z _ {\ text {i}}}$ ${\ displaystyle Z _ {\ text {a}}}$ ${\ displaystyle R _ {\ text {a}}}$ ${\ displaystyle R _ {\ text {i}}}$

Power adjustment is always used when, for example, sensors or antennas need to fully utilize low power. The adaptation can be done with transformers or resonance transformers .

Line adjustment (apparent power adjustment)

If is, it is referred to as reflection or line adaptation and at the same time as apparent power adaptation. In this case the transmission path is homogeneous and the reflected power is minimal. In general, however, the maximum possible active power is not transmitted. ${\ displaystyle Z _ {\ text {i}} = Z _ {\ text {a}}}$

Terms for adaptation: between two devices, alternatively on one device

Mismatch

With every digital or analog interface , the ratio between the output impedance of the source and the input impedance of the load creates a matching damping . In high-frequency technology and in communications technology , reflection matching is always used, with reactive components being avoided and thus power matching at the same time. Any other case is considered a mismatch , in which the power not consumed by the load is reflected back to the source and causes interference there. ${\ displaystyle Z _ {\ text {i}} = Z _ {\ text {a}}}$

literature

Michael Dickreiter, Volker Dittel, Wolfgang Hoeg, Martin Wöhr: Manual of the recording studio technology . 7th completely revised and expanded edition. Published by the ARD.ZDF medienakademie, Nuremberg. 2 volumes. KG Saur, Munich 2008, ISBN 978-3-598-11765-7 .
Otto zince, Heinrich Brunswig: high frequency technology . 6th edition. tape 1 . Springer Verlag, Berlin 2000, ISBN 3-540-66405-X .

Web links

Individual evidence

↑ IEC 60050, see DKE German Commission for Electrical, Electronic and Information Technologies in DIN and VDE: Internationales Electrotechnical Dictionary - IEV. IEV number 702-07-14.
↑ Wilfried Plaßmann, Detlef Schulz: Handbook of electrical engineering: Basics and applications for electrical engineers . Springer Vieweg, 6th edition, 2013, p. 793
^ ^A ^b Reinhold Paul: Electrical engineering: basic textbook. Volume II: Networks . Springer, 1985, p. 191 ff

[IEV-1] IEC 60050, see DKE German Commission for Electrical, Electronic and Information Technologies in DIN and VDE: Internationales Electrotechnical Dictionary - IEV. IEV number 702-07-14.

[2] Wilfried Plaßmann, Detlef Schulz: Handbook of electrical engineering: Basics and applications for electrical engineers . Springer Vieweg, 6th edition, 2013, p. 793

[Paul-3] A ^b Reinhold Paul: Electrical engineering: basic textbook. Volume II: Networks . Springer, 1985, p. 191 ff