Name: voltage balance in closed circuit loops
Uploaded: 2024-04-11T12:48:28.000Z
Duration: 1 min 4 s
Channel: JoVE

K12 Standards

Arizona Science Standards

High School

Physical Science

HS+Phy.P4

HS+Phy.P4U1.8

Kirchhoff's Voltage Law

Das Kirchhoffsche Spannungsgesetz, kurz KVL, basiert auf dem Prinzip der Energieeinsparung.
Sie besagt, dass die algebraische Summe aller Spannungen um einen geschlossenen Pfad oder eine Schleife innerhalb einer Schaltung Null ist.
Die Richtung der Schleife um die Schaltung kann im Uhrzeigersinn oder gegen den Uhrzeigersinn erfolgen und kann von überall aus gestartet werden.
Sobald die Schleifenrichtung gewählt ist, trifft bei positiven Spannungen zuerst der Minuspol und bei negativen Spannungen zuerst der Pluspol.
Wenn Sie KVL auf jede Schleife anwenden und die Terme neu anordnen, erhalten Sie eine alternative Form, die besagt, dass die Summe des Spannungsabfalls der Summe der zugeführten Spannungen entspricht.
Stellen Sie sich zum Beispiel die Weihnachtsbaumbeleuchtung vor, bei der drei in Reihe geschaltete LED-Leuchten aneinandergereiht sind.
Wenn jede Leuchte drei Volt benötigt, um sich einzuschalten, wird die Spannung, die die Batterie benötigt, um diese Leuchten mit Strom zu versorgen, durch Anlegen von KVL bestimmt.
Die Batteriespannung entspricht der Summe des Spannungsabfalls an den drei Leuchten.

kirchhoffsches spannungsgesetz

Das Kirchhoffsche Spannungsgesetz (KVL) ist ein weiteres grundlegendes Prinzip in der Elektrotechnik, eingeführt vom Physiker Gustav Robert Kirchhoff. Dieses Gesetz basiert auf dem Prinzip der Energieerhaltung, welches besagt, dass Energie weder erschaffen noch zerstört, sondern nur von einer Form in eine andere übertragen oder umgewandelt werden kann. KVL besagt, dass die algebraische Summe aller Spannungen um einen geschlossenen Pfad oder eine Schleife innerhalb eines Schaltkreises null ist. Dies bedeutet, dass die gesamte in einer Schleife zugeführte Spannung gleich der gesamten Spannung ist, die über die Komponenten in dieser Schleife abfällt. Die Richtung der Schleife um den Schaltkreis kann im Uhrzeigersinn oder gegen den Uhrzeigersinn sein und kann von jedem Punkt aus beginnen. Sobald die Richtung der Schleife gewählt ist, sind positive Spannungen solche, bei denen zuerst der negative Terminal erreicht wird, und negative Spannungen sind solche, bei denen zuerst der positive Terminal erreicht wird. Durch die Anwendung von KVL in Uhrzeigerrichtung und Umstellen der Terme gibt es eine alternative Form des Gesetzes: Die Summe der Spannungsabfälle über die Komponenten in einer Schleife ist gleich der Summe der zugeführten Spannungen. Betrachten wir zum Beispiel ein Haushaltsbeleuchtungssystem, bei dem drei in Serie geschaltete LED-Leuchten zusammengeschlossen sind. Jedes Licht benötigt drei Volt zum Einschalten. Durch die Anwendung von KVL können wir die für die Batterie benötigte Spannung bestimmen, um diese Lichter zu versorgen. Die Batteriespannung entspricht der Summe des Spannungsabfalls über die drei Lichter, also neun Volt. Damit das KVL gültig ist, muss jedoch eine entscheidende Bedingung erfüllt sein: Ein Schaltkreis kann keine zwei verschiedenen Spannungen parallel enthalten, es sei denn, sie sind gleich. Dies liegt daran, dass in einer Parallelschaltung dieselbe Spannung über alle Komponenten angelegt wird, und jede Diskrepanz würde das Gesetz der Energieerhaltung verletzen.

Kirchhoffsches Spannungsgesetz

Das Kirchhoffsche Spannungsgesetz, kurz KVL, basiert auf dem Prinzip der Energieeinsparung.
Sie besagt, dass die algebraische Summe aller Spannungen um eine geschlossene ...

Education

Lehre

JoVE Core

Electrical Engineering

Elektrotechnik

Unit 1

Einheit 1

Basics of Electric Circuits

Grundlagen elektrischer Stromkreise

KEY TERMS AND CONCEPTS

ZENTRALE BEGRIFFE UND KONZEPTE

voltage balance in closed circuit loops

Kirchhoff's Voltage Law explains how voltage is balanced in a closed circuit loop. It is a basic rule in electrical engineering and comes from the idea of energy conservation. Energy can change form, but it cannot be created or destroyed.

KVL states that the algebraic sum of all voltages around a closed path, or loop, is zero. In other words, the total voltage supplied in a loop equals the total voltage drop across the components in that loop. A loop can be traced clockwise or anticlockwise, and it can begin at any point.

The direction of the loop matters when you assign signs to voltages. If you meet the negative terminal first, the voltage is positive. If you meet the positive terminal first, the voltage is negative. When KVL is written in the clockwise direction and the terms are rearranged, the law can also be stated as the sum of voltage drops in a loop equals the sum of supplied voltages.

A simple household lighting example shows how KVL works. Three LED lights connected in series, with each light needing three volts, require a nine-volt battery to power them. The battery voltage matches the sum of the voltage drops across the three lights.

KVL also depends on an important circuit condition. A circuit cannot contain two different voltages in parallel unless those voltages are equal. In parallel connections, the same voltage appears across each component. If the voltages were different, the circuit would break the rule of energy conservation.

Voltage Balance in Closed Circuit Loops

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kirchhoff's current law

Kirchhoff's Current Law at Circuit Nodes

Kirchhoff's Current Law explains how current behaves at a circuit node. A node is the point where two or more circuit elements meet. The law says the current entering a node equals the current leaving it. That balance follows the rule of charge conservation, which means electric charge is not lost at the junction. When applying KCL, currents entering the node are treated as positive and currents leaving the node are treated as negative. The currents can be added algebraically at the node, and...

kirchhoff's voltage law

Kirchhoff's Voltage Law explains how voltage is balanced in a closed circuit loop. It is a basic rule in electrical engineering and comes from the idea of energy conservation. Energy can change form, but it cannot be created or destroyed. KVL states that the algebraic sum of all voltages around a closed path, or loop, is zero. In other words, the total voltage supplied in a loop equals the total voltage drop across the components in that loop. A loop can be traced clockwise or anticlockwise,...

voltage dividers

Series Resistors and Voltage Split

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design example: resistive touchscreen

Resistive Touchscreen Voltage Mapping

A resistive touchscreen uses voltage mapping to locate a finger touch on a mobile device. It is built from two metallic layers. The top layer is flexible, and the bottom layer is rigid. A narrow gap separates them, and the high resistance between the layers is an important part of the design. When a user touches the screen, the two layers meet at one point. That contact point is called the touchpoint. The touch lowers the resistance between the layers at that spot and changes the electrical...

key terms and concepts

Learn how Kirchhoff's Voltage Law balances voltage in a closed loop, how to assign signs, and why a series LED example needs a 9-volt battery.

Voltage Balance in Closed Circuit Loops | JoVE K12

JoVE Core Electrical Engineering offers easy-to-understand animated videos that cover fundamental concepts of electric circuits along with circuit analysis techniques. It incorporates first-order and second-order circuits using operational amplifiers and circuit transformation concepts. The inclusion of practical design examples and real-world applications through scientist-in-action videos adds significant educational value, making complex concepts accessible.

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Voltage Balance in Closed Circuit Loops

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