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

Tensometr, przetwornik, który przekształca odkształcenia mechaniczne w sygnały elektryczne, jest często używany do pomiaru siły.
Rola inżyniera polega na zaprojektowaniu obwodu mostka Wheatstone'a, umieszczeniu tensometrów w każdym ramieniu i określeniu wymaganego wzmocnienia napięcia wyjściowego. W tym przypadku zakłada się, że przyłożona siła zwiększa rezystancję dwóch tensometrów, podczas gdy rezystancja maleje w pozostałych dwóch. Znana jest również zależność między napięciem wyjściowym mostka a zmianą rezystancji.
Można to osiągnąć za pomocą twierdzenia Thevenina.
Znając napięcie wejściowe, najpierw określa się prądy w górnej i dolnej gałęzi. Wartości te są następnie podstawiane do prawa Ohma w celu obliczenia napięcia Thevenina.
Źródło jest usuwane w celu obliczenia odporności Thevenin, a równoważna rezystancja jest określana w uproszczonej formie.
Z obwodu równoważnego Thevenin napięcie wyjściowe mostka jest obliczane przy użyciu reguły podziału napięcia.
Porównanie uzyskanej zależności ze znaną zależnością pozwala na wyznaczenie wzmocnienia wzmacniacza potrzebnego do zaprojektowania układu do pracy w pożądanym zakresie.

przykład projektu: mostek tensometryczny

Wykorzystanie tensometrów jako przetworników do przekształcania naprężeń mechanicznych na sygnały elektryczne jest powszechną praktyką w różnych zastosowaniach inżynieryjnych. Te tensometry są często integrowane z obwodami mostka Wheatstone'a w celu dokładnego pomiaru parametrów, takich jak siła lub ciśnienie. W tym kontekście każdy element obwodu wykazuje rezystancję, która ulega subtelnym zmianom pod wpływem naprężenia mechanicznego. Podstawowym celem jest przekształcenie niewielkich zmian małego napięcia wyjściowego w bardziej zauważalne napięcie wyjściowe, które można wygodnie odczytać za pomocą woltomierza.

W zakresie obowiązków inżyniera znajduje się projektowanie układu tensometrycznego oraz określenie niezbędnego wzmocnienia w celu dokładnego odwzorowania zmian rezystancji. Opiera się to na zastosowaniu twierdzenia Thevenina, które określa zależność między napięciem wyjściowym mostka a zmianami rezystancji.

Procedura rozpoczyna się od obliczenia napięcia Thevenina, co wymaga wstępnego określenia prądów w górnej i dolnej gałęzi obwodu. W rezultacie te obliczone wartości prądu są podstawiane do prawa Ohma w celu uzyskania napięcia Thevenina. Jednocześnie rezystancję Thevenina wyznacza się poprzez usunięcie źródła napięcia w uproszczonej konfiguracji.

Obwód równoważny Thevenina pozwala określić napięcie wyjściowe mostka na podstawie zasady podziału napięcia. Kluczowym wynikiem tej analizy jest dokładne określenie wzmocnienia wzmacniacza, niezbędnego do zaprojektowania obwodu działającego skutecznie w określonym zakresie operacyjnym.

Przykład projektu: mostek tensometryczny

Tensometr, przetwornik, który przekształca odkształcenia mechaniczne w sygnały elektryczne, jest często używany do pomiaru siły.
Rola inżyniera polega na ...

Education

JoVE Core

Electrical Engineering

Elektrotechnika

Unit 1

Jednostka 1

DC Circuit Analysis

Analiza obwodów prądu stałego

KEY TERMS AND CONCEPTS

KLUCZOWE TERMINY I POJĘCIA

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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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

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Wheatstone Bridge Output for Strain Gauge Design

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