Name: wheatstone bridge output for strain gauge design
Uploaded: 2024-04-11T12:48:31.000Z
Duration: 1 min 15 s
Channel: JoVE

K12 Standards

Texas Essential Knowledge and Skills

High School

Biology

BIO.2

BIO.2.D

design-example-strain-gauge-bridge-or-wheatstone-bridge

Design Example: Strain Gauge Bridge or Wheatstone Bridge

Тензометрический датчик, преобразователь механической деформации в электрические сигналы, часто используется для измерения силы.
Роль инженера заключается в проектировании схемы моста Уитстона, установке тензометрических датчиков в каждом плече и определении требуемого усиления выходного напряжения. Здесь предполагается, что приложенная сила увеличивает сопротивление двух тензодатчиков, в то время как сопротивление уменьшается в двух других. Также известна взаимосвязь между выходным напряжением моста и изменением сопротивления.
Этого можно достичь с помощью теоремы Тевенина.
Зная входное напряжение, сначала определяются токи в верхней и нижней ветвях. Затем эти значения подставляются в закон Ома для вычисления напряжения Тевенина.
Источник удаляется для расчета сопротивления Тевенина, а эквивалентное сопротивление определяется в упрощенном виде.
Из эквивалентной схемы Тевенина выходное напряжение моста рассчитывается с использованием правила деления напряжения.
Сравнение полученного соотношения с известным соотношением позволяет определить коэффициент усиления усилителя, необходимый для проектирования схемы для работы в желаемом диапазоне.

Пример разработки: мостовой тензорезистор

Использование тензорезисторов в качестве преобразователей для преобразования механической деформации в электрические сигналы является обычной практикой в различных инженерных приложениях. Эти тензорезисторы часто интегрируются в мостовые схемы Уитстона для точного измерения таких параметров, как сила или давление. В этом контексте каждый элемент схемы демонстрирует сопротивление, которое претерпевает небольшие изменения при воздействии механического напряжения. Основная цель состоит в том, чтобы преобразовать незначительные изменения небольшого выходного напряжения в более заметное выходное напряжение, которое было бы удобно измерять с помощью вольтметра.

В обязанности инженера входит проектирование конструкции тензорезистора и определение необходимого усиления для точного отражения изменений сопротивления. Это основано на применении теоремы Тевинина, которая устанавливает связь между выходным напряжением мостовой схемы и изменениями сопротивления.

Процедура начинается с расчета напряжения Тевинина, что требует первоначального определения токов как в верхней, так и в нижней ветвях цепи. В результате эти вычисленные значения тока подставляются в закон Ома для получения напряжения Тевинина. Одновременно с этим, сопротивление Тевинина определяется путем удаления источника напряжения в упрощенной конфигурации.

Эквивалентная схема Тевинина определяет выходное напряжение моста с помощью правила деления напряжения. Важный результат этого анализа позволяет точно определить коэффициент усиления усилителя, необходимый для проектирования схемы для эффективной работы в указанном рабочем диапазоне.

Тензометрический датчик, преобразователь механической деформации в электрические сигналы, часто используется для измерения силы.
Роль инженера включает в себя...

Education

JoVE Core

Electrical Engineering

Электротехника

Unit 1

Раздел 1

DC Circuit Analysis

Анализ цепей постоянного тока

KEY TERMS AND CONCEPTS

ОСНОВНЫЕ ТЕРМИНЫ И ПОНЯТИЯ

wheatstone bridge output for strain gauge design

A strain gauge and Wheatstone bridge work together to turn mechanical strain into an electrical signal. In engineering, this setup is often used to measure force or pressure. Each part of the bridge has a resistance that changes slightly when strain is applied.

The main goal is to turn a very small voltage output into a larger, easier-to-read signal. A voltmeter can then measure that output more clearly. To do this, an engineer designs the strain gauge circuit and figures out how much amplification is needed so the resistance change is shown accurately.

The analysis uses Thevenin's theorem, which links the bridge output voltage to changes in resistance. First, the Thevenin voltage is found by calculating the currents in the upper and lower branches of the circuit. Those currents are then used with Ohm's law to determine the voltage.

Next, the Thevenin resistance is found by removing the voltage source and simplifying the circuit. The Thevenin equivalent circuit is then used with the voltage division rule to find the bridge output voltage. This result helps determine the amplifier gain needed for the circuit to work in the correct operating range.

Wheatstone Bridge Output for Strain Gauge Design

wheatstone-bridge-output-for-strain-gauge-design

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maximum power transfer

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design example: strain gauge bridge or wheatstone bridge

A strain gauge and Wheatstone bridge work together to turn mechanical strain into an electrical signal. In engineering, this setup is often used to measure force or pressure. Each part of the bridge has a resistance that changes slightly when strain is applied. The main goal is to turn a very small voltage output into a larger, easier-to-read signal. A voltmeter can then measure that output more clearly. To do this, an engineer designs the strain gauge circuit and figures out how much...

key terms and concepts

Learn how a strain gauge and Wheatstone bridge convert strain into voltage, and how Thevenin's theorem helps find the amplifier gain needed.

Wheatstone Bridge Output for Strain Gauge Design | 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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Wheatstone Bridge Output for Strain Gauge Design

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