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

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Fourier Transform involving frequency differentiation property

Going through some past exams, I've came across this question; To get started, I've noticed that it resembles to the frequency differentiation property; Now, the differentiation was extremely ...
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58 views

Fourier Transform help

I have this question here, which I am unsure of my final answer: Firstly, I times the numerator and denominator by the conjugate 1-jt - resulting me in the alternate form of the function Next, I've ...
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3answers
99 views

Fourier Transform of a half triangle

I have to derive the Fourier transform of a half triangle which is shown here: So far I got the equation of the line as 1-t/T, and now I think that I have to substitute into the Fourier transform ...
2
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2answers
114 views

Check my math: Calculating the size of extension cord needed

I think I've done this right, but I don't trust myself. Will you check my math and see if I'm right about this, or correct my error if I'm wrong? The facts I have a device (A Yamaha Stagepas 400i ...
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1answer
36 views

FWHM of something which does not reach half of maximum?

There is some curve for which I have find FWHM. But the curve does not reach half maximum i.e., its maximum is 1 and it only reaches .7 (but it does have the bell curved shape the filters have). Right ...
2
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2answers
108 views

When is it theoretically possible to fit PCB circuit on x Layers (emphasis: x =1)

When is it theoretically possible to fit a given circuit on a certain number of layers? (Presumably PCB layers.) What is/are the name of the mathematics/algorithms that might determine this, or ...
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1answer
68 views

Electrical Engineering Math, showing time independence? how?

I have a cheat sheet provided by the teacher about the calculation of the Coherence Time, however I get lost along the way. There are 2 paths of a signal at: Path 1: \$\phi_1(t) = ...
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1answer
31 views

How to calculate the oscillator capacitor value for a switched capacitor (MAX7405)?

I would like to use an 8-order LPF switched capacitor: MAX7405 datasheet The cut-off frequency can be set by simply connecting an external oscillator capacitor, Cosc. I would like to design a 50Hz ...
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1answer
139 views

Would it be practical to build a chip that can do this math?

I was theorizing a new kind of 64-bit number for use in data storage, but then started wondering if it could become practical if created in hardware. (I believe it would be too slow if only software ...
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2answers
67 views

Cascading Low Pass Filter Parameters

I'm trying to implement two cascaded low pass filters in a software application so that I can smooth out a potentially volatile data set. Based on the incoming data, I want a signal to be turned ...
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1answer
242 views

How to calculate the resistance of a complicated circuit?

I learned in high school the basic rules of how to compute resistance between two points, given a network of resistors. You try to rearrange the circuit so into parallel parts and series parts, then ...
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1answer
102 views

What's wrong with my boost converter math?

I'm working some equations for a boost converter, and running into a contradiction I don't understand. Assume a steady state, perfect efficiency, and continuous conduction. Total instantaneous ...
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3answers
83 views

Signal to noise ratio for a non-physical property

The signal to noise ratio for a voltage, current, or power is easy to understand, but how do I calculate the SNR when the signal is not a physical property, but instead an abstract quantity? I'll try ...
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0answers
35 views

Is there a “integer divide” function in PSIM?

I want to use the "Math function" voltage source in PSIM, and implement a time dependented voltage source, and want to use a "integer divide" function, is there some similar functions in PSIM? ...
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2answers
39 views

Is there any correlation between eigen functions and eigen vectors of an LTI system?

Eigen functions are the origin for Laplace transform while eigen vectors is for state space representation.Can we relate the eigen concept in these two? The complex exponential functions, are eigen ...
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2answers
108 views

Simulating accelerometer noise

I would like to create a software simulation of an accelerometer (MPU-6000). As part of that simulation, I need to model the noise on the accelerometer signal. According to the datasheet of the chip, ...
2
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1answer
53 views

Converting a summation to an integration

I've seen it done a few times, it's always roughly apparent that "oh yeah, okay, they've dropped this, pulled this there, yeah, okay, kind of convincing" - but I've never why or how to do it for ...
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1answer
97 views

Number of independent KVL equations in a circuit?

Why, for a circuit with B branches and N nodes, the number of the linearly independent KVL equations for a network is: B-N+1 ?
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7answers
462 views

How do we know loop currents exist?

I've been practising loop analysis questions, but don't really understand why the method is valid. Say you have a circuit that only consists of resistors and some power source. Assume the circuit is ...
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3answers
97 views

Why are the Resistance/Resistivity Equations Formulated as they are?

The equation for temperature dependence on resistivity: $$ \rho(dT) = \rho(0)(1+\alpha dT) $$ where \$dT\$ is change in temperature from some reference and \$rho\$ is resistivity. This leads to ...
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1answer
142 views

Frame size range calculation for stop-and-wait protocol

I have a question and answer below. The answer seems to show less working on how it derived. My question is if the efficiency of at least is changed to say 60%? Will it still be the same answer? ...
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1answer
104 views

To what extent can Gielis' so-called “Superformula” be used to improve the efficiency of WIFI antennas? [closed]

I am new to this Stack Exchange venue, so please don't shoot me if this question is not appropriate. This question was taken Math Stack Exchange. In 2003, the Belgian plant biotechnologist Johan ...
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3answers
380 views

How long can I practically power an IC with a capacitor?

If I have, for example, an IC that draws 10mA @ 3.3V, how large of a capacitor would I need to power it for 2 minutes? 5 minutes? I understand that using capacitors to power an IC is not the most ...
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0answers
99 views

Understanding how bypass caps work, mathematically

Assume there is a band of noises that you you want to filter with center frequency Fn. Then The complex voltage representing noise at frequency F is V_(F, T) = V(F) e^(i W(F) T), where V(F) is the ...
2
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1answer
79 views

Is there a convention for the polarity of voltage specified as \$V_{XY}\$? [duplicate]

Inspired by this answer, which includes the image: Which solicited the comment: No, you have the polarity of Vce shown backwards in the diagram [...] The diagram seems consistent to me: the ...
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2answers
57 views

Are there other uses for the value of RMS current besides heating computations?

For most purposes I've personally encountered, RMS current and voltage have been useful only for computing heat losses in a resistor. Do RMS current or voltage have other applications besides ...
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4answers
1k views

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 ...
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1answer
293 views

Tracking 2D positioning with IMU Sensor

I am using a miniature car and I want to estimate the position. We can not use GPS modules and most of the tracking systems that I saw, are using IMU senson with the GPS module. In our car we are able ...
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3answers
117 views

How do I size fuses to handle sudden changes in AC line voltage into a capacitive load?

Suppose I have a rectifier on the AC line, followed by some caps and a load. simulate this circuit – Schematic created using CircuitLab If the AC line is suddenly increased, there's a ...
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1answer
131 views

Capacitor discharge math discrepancy

I'm trying to cross check mathematically the mA being discharged from a .33uF capacitor which is charged to about 1200V by a circuit which is provided 37W of power to it. I do it three ways. 1) ...
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1answer
407 views

What is the fastest logic gate?

I have been told that the fastest logic gate family is ECL. My first question: Is this true? In this or another family (Depending on the answer to the above question), Is there any particular gate ...
0
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1answer
103 views

Affine Non Autonomous State Space system

Normally We all know the state space model of the the form der(x) = F*x(t)+G*u(t) y = H*x(t)+J*u(t). However I came across a state space model which has the following form der(x) = F*x(t)+G*u(t) + ...
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1answer
69 views

Z-Transform Initial Value Theorem

I have a small understanding of how to solve limits to infinity for regular rational equations, but I'm unsure of how to apply this to the Z-Transform initial value theorem. The equation is: \$ ...
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2answers
172 views

Average Power Formulas

I've becomes a bit confused with the average power formulas. These formulas can be found on Wikipedia here and here. Let's suppose V(t) = 1V (DC) and we have a square wave for the current that ...
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2answers
143 views

Salvage data from a reverse connected thermocouple?

My SAE Baja team had a competition this past weekend, and we were using some thermocouples in order to get some temperature data on the drivetrain and engine. They were hooked up right before the ...
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1answer
308 views

What is the physical meaning of an LC circuit having a negative transfer function?

Say you have an ideal LC circuit: simulate this circuit – Schematic created using CircuitLab The transfer function of this circuit is a complex voltage divider: $$ \frac{\frac{1}{sC}}{sL ...
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2answers
374 views

Converting raw temperature data to Celcius L3GD20

I have an L3GD20, which is an accelerometer with a temperature sensor built in, and I want to make sure my math isn't funky regarding the temperature. I'm not exactly experienced with embedded ...
5
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1answer
130 views

Need help interpreting a basic circuit question

In my Nilsson "Electric Circuits, 5th ed" book, there's this drill exercise near the beginning of the book. Here it is: Current at the terminals of the element is t<0: $$ i=0 $$ t>=0: ...
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3answers
176 views

Attempting to determine power consumption

So I am attempting to determine if the battery I choose can power the devices I need. This is my first day doing anything with ohms and current and such. So go easy. I have: 2000mAh battery 45mA ...
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2answers
554 views

Overflow detection in a CSA (Carry-save Adder)

How do you detect overflow when you have a CSA? I have 3 16-bit two's complement inputs and a 16-bit output and I'm wondering how do I detect overflow?
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0answers
78 views

JFET “How to find resistance of the device”

I have this homework question that I can find one way to get the answer but I want to use a certain equation "attached" to find the answer also. I'm having a hard time understanding what to ...
2
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1answer
57 views

How does one compute the ripple currents seen by an active PFC output capacitor?

Suppose one is designing a single-phase power-factor-corrected power supply, with a known average current load: The ripple current seen by the output capacitor is critical. If that current is too ...
0
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1answer
126 views

Find the peak load of a power plant for the given load equation

The daily load demand of a grid is given by $$P=P_{max} \cdot cos(\pi t/24)$$ Here \$-12hrs ≤ t ≤ 12hrs\$. Maximum power occurs at (\$t=0\$) and minimum occurs at (\$t= ±12\$). A \$10 GW\$ hydro ...
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2answers
670 views

Double-Subscript Notation for Voltages

I have read from some book that: "The voltage quantity symbol V sometimes has subscripts to designate the two points to which the voltage corresponds. If the letter a designates one point and b the ...
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4answers
359 views

Component with an impedance that has a negative real part

Is there an electrical component such that its impedance has a negative real part ? Fact: Any electrical component made from resistors, inductances, capacitors (connected in possibly complex ways ...
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2answers
299 views

ARM Power/Exponential Function

I'm trying to code an exponential function for use on a PWM signal. My question is, does anyone know how to do a power function on an ARM cortex-M (STM32F4 in this case, which has an FPU) ...
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2answers
296 views

basic math question about voltage, ohms, resistance

total n00b here. After working on several projects by copy & paste from other people's schematics and code, I'm finally digging in and learning some of the math to know what I'm doing. If I have ...
3
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1answer
209 views

Convert between dBA, dBV and RMS values

How do I convert between dBA, dBV and RMS values? For example, I have used a current probe (clamp) with a gain of 100mV = 1A to measure a series of currents in dB and I would like to know the ...
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2answers
8k views

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 ...
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2answers
1k views

I have to determine if the signal is linear, time-invariant, and/or causal

Here is my problem: $$\frac{d^2y}{dt^2} + 5\frac{dy}{dt} + 8y(t) = \frac{dx}{dt} + 3x(t)$$ I have to prove if this system is homogeneous and additive in order for the function to be linear, but can ...