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

يعتمد قانون الجهد الخاص ب Kirchhoff ، أو KVL ، على مبدأ الحفاظ على الطاقة.
تنص على أن المجموع الجبري لجميع الفولتية حول مسار أو حلقة مغلقة داخل الدائرة يساوي صفرا.
يمكن أن يكون اتجاه الحلقة حول الدائرة في اتجاه عقارب الساعة أو عكس اتجاه عقارب الساعة ويمكن أن يبدأ من أي مكان.
بمجرد اختيار اتجاه الحلقة ، تتم مواجهة الفولتية الموجبة طرفها السالب أولا ، وتواجه الفولتية السالبة طرفها الموجب أولا.
يؤدي تطبيق KVL على كل حلقة وإعادة ترتيب المصطلحات إلى إعطاء شكلها البديل ، والذي ينص على أن مجموع انخفاض الجهد يساوي مجموع الفولتية الموردة.
على سبيل المثال ، ضع في اعتبارك أضواء شجرة عيد الميلاد حيث يتم ربط ثلاثة مصابيح LED متصلة في سلسلة معا.
إذا تطلب كل ضوء ثلاثة فولت لتشغيله ، تحديد الجهد اللازم للبطارية لتشغيل هذه المصابيح عن طريق تطبيق KVL.
جهد البطارية يساوي مجموع انخفاض الجهد عبر الأضواء الثلاثة.

قانون كيرشوف للجهد

<div style="direction:rtl">قانون كيرشوف للجهد (KVL) هو مبدأ أساسي آخر في الهندسة الكهربائية، قدمه الفيزيائي غوستاف روبرت كيرشوف. هذا القانون متجذّر في مبدأ حفظ الطاقة، الذي ينص على أن الطاقة لا تفنى ولا تفنى، بل تنتقل أو تتحول من شكل إلى آخر. ينص KVL على أن المجموع الجبري لجميع الفولتية حول مسار مغلق أو حلقة داخل الدائرة هو صفر. وهذا يعني أن إجمالي الجهد المتوفر في الحلقة يساوي إجمالي انخفاض الجهد عبر المكونات في تلك الحلقة. يمكن أن يكون اتجاه الحلقة حول الدائرة في اتجاه عقارب الساعة أو عكس اتجاه عقارب الساعة ويمكن أن يبدأ من أي نقطة. بمجرد اختيار اتجاه الحلقة، فإن الفولتية الموجبة هي تلك التي يتم فيها مواجهة الطرف السالب أولاً، والجهود السالبة هي تلك التي يتم فيها مواجهة الطرف الموجب أولاً. من خلال تطبيق KVL في اتجاه عقارب الساعة وإعادة ترتيب المصطلحات، هناك شكل بديل للقانون: مجموع انخفاض الجهد عبر المكونات في الحلقة يساوي مجموع الفولتية الموردة. خذ بعين الاعتبار، على سبيل المثال، نظام إضاءة منزلي حيث يتم ربط ثلاثة مصابيح LED متصلة على التوالي معًا. يتطلب كل ضوء ثلاثة فولت لتشغيله. من خلال تطبيق KVL، يمكننا تحديد الجهد اللازم للبطارية لتشغيل هذه المصابيح. جهد البطارية يساوي مجموع انخفاض الجهد عبر المصابيح الثلاثة، وهو تسعة فولت. ومع ذلك، لكي يكون KVL صحيحًا، يجب استيفاء شرط حاسم: لا يمكن للدائرة أن تحتوي على جهدين مختلفين متصلين على التوازي إلا إذا كانا متساويين. وذلك لأنه في التوصيل الموازي، يتم تطبيق نفس الجهد على جميع المكونات، وأي تناقض من شأنه أن ينتهك قانون الحفاظ على الطاقة.</div>

يعتمد قانون الجهد الخاص ب Kirchhoff ، أو KVL ، على مبدأ الحفاظ على الطاقة.
تنص على أن المجموع الجبري لجميع الفولتية حول مغلق ...

Education

JoVE Core

Electrical Engineering

الهندسة الكهربائية

Unit 1

الوحدة الأولى

Basics of Electric Circuits

أساسيات الدوائر الكهربائية

KEY TERMS AND CONCEPTS

المصطلحات والمفاهيم الأساسية

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

charge and current

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circuit terminology

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independent and dependent sources

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ohm's law

Resistance and Conductance in Circuits

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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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current dividers

Parallel Resistors and Current Division

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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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