Electrical Engineering Stack Exchange
Electrical Engineering Stack Exchange

Questions tagged [equation]

75 questions
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3 answers

I think I found an error in an electronics book. Are my equations correct here?

I'm reading Practical Electronics for Inventors, 4th edition, to freshen up my long forgotten knowledge of electronics. I love the book so far, but I just came across an equation there which seems incorrect. I don't want to immediately assume that…
bnorb
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4 answers

Mathematically modelling RC circuit with a linear input

I have found a plenty of documents and books that model how the voltage across a capacitor behaves within a transient RC circuit, using the following equation: $$V_C=V_{MAX}(1-e^{-t/RC})$$ Unfortunately, I have found no resource that discusses how…
CTXz
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2 answers

Deliyannis-Friend design: where is my mistake?

I am losing my mind over this. I am trying to design a Deliyannis-Friend section and I am stuck in a loop and don't know what to do. These is the circuit and its equations. Based on this I have devised a design method. The design starts by setting…
Granger Obliviate
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1 answer

Equation to calculate voltage divider resistor value for an input of op-amp

I found this guide for a temperature sensing circuit design with NTC thermistor by Texas Instruments. According to my opinion, optimum R1 value is calculated so that the voltage divider can provide the widest voltage variation at its output for the…
Yasindu
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Length of wires after they are twisted?

I have looked all over and haven't seen any questions about this topic. This may be more of a mechanical question, but none the less, the dilemma on hand is how does twisting a set of equal length wires affect the end length? Through some side work,…
Don
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Confused on the notation from a TI datasheet

So I'm trying to implement this IC onto a controller that I'm designing: https://www.ti.com/product/UCC5350 I understand for the most part how to apply it, I am just lost on one key part The specific point on concern that I have is the double…
Godin
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1 answer

RC Circuit Equation

I am a beginner electronics hobbyist. I found this book called Basic Electronics for Scientists and Engineers and I am currently reading on RC circuits but got stuck trying to understand the equation. simulate this circuit – Schematic created using…
Edwin
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3 answers

Finding equation of curve for NTC type thermistor

I have an NTC thermistor from the KTM 390 engine which I am trying to interface with the Arduino MEGA. The problem is the sensor has no datasheet. I have got the relation between the temperature vs resistance for the thermistor form another person…
Niranjan Tarle
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1 answer

State variable equations for a RLC circuit

What are the state variable equations of this RLC circuit? How do I write the final matrix? I tried to write the equations for the capacitor and inductor: $$L\frac{di_3}{dt}=v_1-v_C \leftrightarrow…
Carmen González
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I need an equation to calculate the time for a power percentage of a half cycle sine wave into a resistive load

I need to calculate the time a thyristor/triac needs to be on for a desired percentage of full power of each half cycle of the AC line input. On for the full half cycle will give me 100%. On for 1/2 half the cycle will give me 50%. (sounds easy so…
Rudy
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Differential equation of an OP AMP circuit with RC elements

I have to find the differential equation which describes the relation between input and output voltage for the circuit below. Per how the RC components are arranged, I simply can not find a differential equation only including \$V_\text{in}\$. All I…
M. Matthias
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Crystal capacitor selection equation

So I've recently discovered that when a crystal oscillator says "20pF", it does not mean "use 20pF caps". (Despite that the design I made under that assumption appears to work.) However, I see two different equations used in different places. …
Erhannis
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Nodal Analysis with constraint equation

We were asked to form the node-voltage equations of this circuit. But how can I form the equation that specifies the constraint imposed by the controlled voltage source on the nodes it is connected to? All the equations must be in the form of v1,…
awit ka gHorl
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1 answer

Seeking clarification on equation used in MIPS assembly problem

I'm currently studying MIPS assembly code, and I'm having trouble understanding the solution for question (b) of a particular problem. I was hoping someone could help me clarify a specific part of the solution. Here's the problem and the given…
Frank
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5 answers

Sallen-Key LP design algorithm

I am facing this design from Analog Devices: Image source: Analog Devices - Mini Tutorial MT-222, Sallen-Key Filters I don't understand how they reach the value for the coefficient m. I did a sanity test and the expressions match but "m" needs to…
Granger Obliviate
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