Electrical Engineering Stack Exchange
Electrical Engineering Stack Exchange

Questions tagged [math]

Math or Mathematics is the abstract study of topics such as quantity (numbers), structure, space, and change.

Mathematics is the abstract study of topics such as quantity (numbers), structure, space, and change. There is a range of views among mathematicians and philosophers as to the exact scope and definition of mathematics.

Concepts in engineering are generally analyzed using mathematical models. Any given concept or component may have more than one applicable model, with each having varying degrees of precision or domains of application.

Processes can generally be divided into continuous-domain and discrete-domain. Continuous-domain processes can be modeled using differential equations, while discrete-domain processes can be modeled using difference equations. In principle, a complete mathematical model of a system allows one to compute any past or future state of the system. However, in the case of systems which exhibit a mixture of continuous and discrete dynamics, no single set of equations can provide a complete mathematical model.

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Why does hardware division take much longer than multiplication?

Why does hardware division take so much longer than multiplication on a microcontroller? E.g., on a dsPIC, a division takes 19 cycles, while multiplication takes only one clock cycle. I went through some tutorials, including Division algorithm and…
Marko Gulin
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Why V rms instead of V average?

I'm looking at an equation for average power in a signal $$ p_{avg} = \frac{1}{R} v_{rms}^2 $$ and wondering why it isn't $$ p_{avg} = \frac{1}{R} |v|_{avg}^2 $$
Rob N
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Why is the time constant 63.2% and not 50% or 70%?

I am studying about RC and RL circuits. Why is the time constant equal to 63.2% of the output voltage? Why is it defined as 63% and not any other value? Does a circuit start working at 63% of output voltage? Why not at 50%?
Bala Subramanian
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How to determine position from gyroscope and accelerometer input?

I have a 3-axis accelerometer and a 2-axis gyroscope. I intend to measure something that only moves in the X and Z axis. I've heard of using Kalman filters to smooth out the acceleration vectors, but I can't find a good tutorial for a complete…
Steven
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How do computers calculate sin values?

How does a computer calculate a sin value? Logically, when I think about it the only apparent way is to put many sin values into memory, and when a sin value needs to be "calculated" it would just pull data from a specific memory address.(ex. sin(x)…
zack1544
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Why is impedance represented as a complex number rather than a vector?

I am trying to understand why impedance is not represented using vectors. I assume it is due to complex numbers having the property that $$j = \sqrt {-1}$$ but with my limited knowledge I can't see how this relates to impedance or why this property…
JShorthouse
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Do working electrical engineers in circuit design ever use textbook formulas for rise time, peak time, settling time, etc

This is a very general question. In undergrad electrical engineering, students are usually taught about step response to LC (second order) circuits. This is usually when many parameters are introduced, some of which are rise time peak time…
Fraïssé
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What is the function of a Fourier Series?

What is a Fourier Series? What it is used for?
coldshine
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how to select capacitor values

I am trying to find information on formulas used to calculate capacitance required for a given circuit. Not a circuit in particular, just in general how to figure out what value should be used. I know about selecting voltage ratings at least 20%…
rob j loranger
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Acceleration when device is on tilt

I'm currently working on device that uses always-on 3D accelerometer(using scale +-2g) and 3D gyroscope(using scale +-250g) -sensor. I can read every possible vector (X,Y,Z) and their acceleration (g's) and angular rate (dps) and also the angle…
jumbojohn
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Mathematical proof that RMS voltage times RMS current gives mean power

I know this is true because I read it in a reputable source. I also understand intuitively that power is proportional to the square of voltage or current for a resistive load, and that the "S" in RMS is for "square". I am seeking a hard mathematical…
Phil Frost
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Advanced Math in day to day Electronics?

So i've been watching the MIT 6.002x Classes and they are really interesting, I feel like i've got a good grasp of Circuits and the Basics (I graduated with a CS degree...but EE appeals to me too). Anyways I noticed....probably like a lot of people…
user3073
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Why does the base-emitter voltage of a BJT decrease with temperature?

According to Sedra/Smith Microelectronic Circuits, \$v_{BE}\$ changes by \$-2\text{mV}/\text{°C}\$. I cannot understand how this could possibly be the case given the equations I am familiar with. With all currents kept constant, we…
Gordon Bailey
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software for obtaining differential equations for circuit simulation

Does any of the common circuit simulation software provide the system equations? Deriving a system of 1st-order differential equations for a circuit by hand is kind of a pain. And yes, I know that the simulators will actually run the simulations for…
JustJeff
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Constant power discharge of a non-ideal capacitor

My employer sells boost converters to hold up motor drives during power loss. These boost converters are fed from capacitor banks. In order to size these banks correctly, we need to take their voltage, capacitance, and ESR into account, to ensure…
Stephen Collings
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