Name: analyzing an op amp audio filter
Uploaded: 2024-04-11T12:48:50.000Z
Duration: 1 min 18 s
Channel: JoVE

في النظام الصوتي ، تعالج دائرة المرشح الإشارة الصوتية المضخمة من مكبر للصوت ، مما يخفف بقوة من مكونات الإشارة ذات الترددات المنخفضة.
ضع في اعتبارك أبسط دائرة مرشح تتكون من مضخم صوت في تكوين مقلوب مقترن بالمقاومات R1 و R2 والمكثف C1. ما هي إشارة الخرج الناتجة لإشارة إدخال معروفة؟
يتم حساب مقاومة المكثف باستخدام التردد الزاوي المشتق من تعبير المجال الزمني لجهد الإدخال.
تمثل الدائرة المكافئة لمجال التردد إشارة الدخل في الشكل القطبي والمعاوقة Z1 و Z2. تتوافق المعاوقة Z2 مع المجموعة المتوازية للمكثف C1 والمقاوم R2.
يؤدي تطبيق قانون كيرشوف الحالي وقانون أوم في العقدة إلى معادلة عقدية لمضخم صوت مثالي. تشير هذه المعادلة ، عند إعادة ترتيبها ، إلى أن نسبة الإخراج إلى جهد الدخل تساوي النسبة السالبة للمعاودة.
من خلال استبدال القيم المعروفة والمحسوبة في هذه المعادلة ، يتم تحديد جهد الخرج في شكل قطبي ، والذي يتم تحويله بعد ذلك إلى المجال الزمني.

دوائر op amp ac

<div style="direction:rtl">داخل النظام الصوتي، تلعب دائرة المرشح دورًا محوريًا في معالجة الإشارة الصوتية المضخمة من مكبر الصوت. وتتمثل وظيفتها الأساسية في تخفيف مكونات الإشارة ذات الترددات المنخفضة بشكل كبير، وبالتالي تشكيل إخراج الصوت. يتم فحص عمليات هذه الدائرة، مع التركيز على التكوين الأساسي للمرشح. يتضمن هذا التكوين مضخمًا تشغيليًا مرتبًا في إعداد مقلوب مقترنًا بمقاومات (R1 و R2) ومكثف (C1).
 <img alt="Figure1" src="/files/ftp_upload/15116/15116_PT_Figure_1.svg" style="text-align: center; height: 164px;"> 
 عند مواجهة إشارة دخل معروفة، يكمن التحدي في تحديد إشارة الخرج الناتجة. تتضمن الخطوة الأولى حساب ممانعة المكثف، والتي يتم تحقيقها من خلال استخدام التردد الزاوي المشتق من تعبير المجال الزمني لجهد الدخل. 
 <img alt="Equation1" src="/files/ftp_upload/15116/15116_PT_Equation_1.svg" style="text-align: center; height: 36px;"> ونتيجة لذلك، ينتقل التحليل إلى مجال التردد، حيث يتم تمثيل إشارة الدخل في شكل قطبي إلى جانب مكونات المعاوقة Z1 و Z2. يرتبط Z2 بوضوح بالتركيبة المتوازية للمكثف C1 والمقاوم R2. يعتمد جوهر التحليل على تطبيق قانون كيرشوف للتيار وقانون أوم على عقدة محددة في الدائرة، وبالتالي صياغة معادلة عقدية لمضخم تشغيلي مثالي. تكشف هذه المعادلة، عند إعادة ترتيبها، عن رؤية مهمة: نسبة الخرج إلى جهد الدخل تتناسب عكسيًا مع نسبة الممانعات. 
 <img alt="Equation2" src="/files/ftp_upload/15116/15116_PT_Equation_2.svg" style="text-align: center; height: 36px;"> يتم استبدال القيم المعروفة والمحسوبة بمهارة في هذه المعادلة للكشف عن جهد الخرج في الشكل القطبي. يمكن بعد ذلك تحويل النتيجة، التي تمثل جهد الخرج، إلى المجال الزمني، مما يوفر فهمًا شاملاً لاستجابة دائرة المرشح لإشارة الدخل. بالنسبة للتحليل، غالبًا ما يتم افتراض خصائص المضخم التشغيلي المثالية، بما في ذلك مبدأ عدم دخول أي تيار إلى أي من أطراف الإدخال الخاصة به وأن الجهد عبر أطراف الإدخال الخاصة به يظل صفرًا.
</div>

دوائر Op Amp AC

في النظام الصوتي ، تعالج دائرة المرشح الإشارة الصوتية المضخمة من مكبر للصوت ، مما يخفف بقوة من مكونات الإشارة بانخفاض ...

Education

JoVE Core

Electrical Engineering

الهندسة الكهربائية

Unit 1

الوحدة الأولى

AC Circuit Analysis

تحليل دوائر التيار المتردد

KEY TERMS AND CONCEPTS

المصطلحات والمفاهيم الرئيسية

Op Amp AC Circuits

analyzing an op amp audio filter

An op amp audio filter shapes an amplified sound signal by strongly reducing the lower-frequency parts. In this circuit, the focus is on a basic filter setup used after an amplifier in an audio system. The filter uses an operational amplifier in an inverting arrangement with resistors R1 and R2 and a capacitor C1.

The analysis starts with a known input signal and asks for the output signal. To solve it, the capacitor impedance is found first. That requires the angular frequency from the time-domain form of the input voltage, so the work moves into the frequency domain.

In the frequency domain, the input signal is written in polar form. The impedances Z1 and Z2 are then used, with Z2 representing the parallel combination of capacitor C1 and resistor R2. At the same time, the ideal op amp assumptions are used. No current enters either input terminal, and the voltage across the input terminals is zero.

The final step is applying Kirchhoff's current law and Ohm's law at one node in the circuit. This creates a nodal equation for the ideal op amp. When that equation is rearranged, the output-to-input voltage ratio is shown to be inversely proportional to the impedance ratio. The known values are then substituted to find the output voltage in polar form, and that result can be converted back to the time domain for a full description of the filter response.

Analyzing an Op Amp Audio Filter

sinusoidal sources

AC Waveform Basics and Phase

Alternating current, or AC, changes direction and magnitude over time, unlike direct current, or DC, which flows in one direction with constant polarity. AC is the main form of electricity used for modern power transmission and distribution because it can travel long distances efficiently. In homes, power supplies use sinusoidal sources to deliver electricity. A sinusoidal source creates a voltage that rises and falls in a smooth wave-like pattern. This waveform is called a sinusoid, which is...

graphical and analytic representation of sinusoids

graphical-and-analytic-representation-of-sinusoids

Measuring Sinusoid Phase on an Oscilloscope

Measuring sinusoid phase on an oscilloscope helps compare two sinusoidal voltages with the same amplitude and period. An oscilloscope is an instrument used to display and analyze waveforms. The process starts by reading the peak-to-peak value, which is twice the amplitude of the sinusoid. This shows the maximum voltage swing of the waveform. Next, the period and angular frequency are measured. The period is the time for one complete cycle. Angular frequency, often written as omega, is the rate...

phasors

Phasors for AC Circuit Analysis

Phasors are a mathematical tool for analyzing alternating current, or AC, circuits. They represent sinusoids with complex numbers. The phasor magnitude matches the sinusoid amplitude, and the phasor angle shows the phase measured from the positive x-axis. Phasors make AC circuit analysis simpler by removing time from the current and voltage expressions. That lets an AC circuit be treated like its equivalent direct current, or DC, form for calculations. Phasors can also be written in...

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Phasor Rules for AC Circuit Analysis

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phasor relationships for circuit elements

phasor-relationships-for-circuit-elements

AC Circuit Phasors: Resistor, Inductor, Capacitor

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kirchoff's laws using phasors

AC Circuit Rules with Phasor Diagrams

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AC Circuit Response: Impedance and Admittance

AC circuit response changes with frequency, and impedance describes how resistors, inductors, and capacitors affect sinusoidal current flow. In phasor form, voltage and current are used to show this behavior in a clear way. Impedance is a key idea in AC circuit analysis because it measures opposition to current in an alternating circuit. These components behave differently in AC than in DC. In DC circuits, inductors act like short circuits and capacitors act like open circuits. In AC circuits,...

impedance combination

Series and Parallel Impedance Rules

Impedance in series and parallel circuits follows the same rules used for resistors. A string of Christmas lights is a simple example. Each bulb represents one impedance element. In a series connection, the current stays the same through every component. This series behavior matches Kirchhoff’s Voltage Law, or KVL. The total impedance in the circuit is the sum of the individual impedances. The source voltage is then divided among the components based on their values. This is the voltage...

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AC Circuit Node Method in an Angioplasty Model

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Impedance Matching with Mesh Currents

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AC Source Conversion in Circuit Analysis

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norton equivalent circuits

Norton Current in AC Circuit Analysis

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Analyzing Mixed-Frequency Linear Circuits

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op amp ac circuits

An op amp audio filter shapes an amplified sound signal by strongly reducing the lower-frequency parts. In this circuit, the focus is on a basic filter setup used after an amplifier in an audio system. The filter uses an operational amplifier in an inverting arrangement with resistors R1 and R2 and a capacitor C1. The analysis starts with a known input signal and asks for the output signal. To solve it, the capacitor impedance is found first. That requires the angular frequency from the...

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key terms and concepts

Learn how an op amp audio filter reduces low-frequency signals. Follow impedance, nodal analysis, and polar-to-time-domain output calculations.

Analyzing an Op Amp Audio Filter | 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.

electrical engineering

Analyzing an Op Amp Audio Filter

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