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

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115 views

How do I compute the average and RMS of a series of triangular pulses?

I'm trying to calculate the Average and RMS values of the current through a diode with the waveform image attached. I'm struggling to work out which equations to use. Any feedback would be appreciated....
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0answers
33 views

Mathmatically analizing different voltages in a phase changing circuit

I am trying to understand a phase shift oscillator from a mathematical perspective, and to begin I simply took the phase-shifting part of the circuit and am now trying to analyze the voltages as a ...
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3answers
62 views

Studying electronic filters

I'm studying this filter: And I want to know all the important points in this filter (the math way), can someone help me? What are the trivial points in this filter? My Work, transfer function: ...
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0answers
68 views

FPGA Multiplication and Division

Background I am trying to estimate the speed of a quadrature encoder with the following equation v = Δx/Δt Δx is a 16 bit signed integer and Δt is a 16 bit ...
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1answer
47 views

Park/Clarke Transform and Power

I'm looking to determine the electrical power input to a 3-phase BLDC motor, driven by TI's DRV8305 motor controller. I can't use the DC power flowing into the system because I'm trying to capture the ...
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4answers
715 views

Performing FFT at low frequencies but high resolution?

To put this in context, I'm looking to achieve both high speed and high accuracy for measuring biosignals through the FFT. I'll describe a quick example to see if I understand this properly as well as ...
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3answers
55 views

PID Control: Controller of the type \$\dfrac{1}{s+k}\$

In PID control an integrator action is represented by \$\dfrac{1}{s}\$ Does anyone know what would be the effect of using \$\dfrac{1}{s+k}\$ instead of \$\dfrac{1}{s}\$, where \$k\$ is a constant? ...
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0answers
32 views

Accuracy calculation for SMD compass magnet-triangulation

I'm designing for an application where size is to be kept at a minimum (board space of a square inch or less; boards should be circular or square, not long in one axis, or they might break). I want to ...
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4answers
424 views

converting watt values over time to kWh

This is probably an elementary question, but I wanted to be sure. I have a system that reads instantaneous watts values, and stores them as "events", with a power value and a time value. According ...
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1answer
24 views

PV array project

I am working on a PV array on simulink and I just need help on a math question. On the article I'm basing the model on, the model voltage equation is Vm = VmT - (5- G/0.2) for the voltage to vary ...
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0answers
26 views

VLSI and Carry save adder (CSA) and multiple operand addition?

I read this PPT on page 146 we have this figure: as Better to have the same sum and carry delays (both contribute to critical path) in Carry save adder (CSA) and multiple operand addition. ...
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0answers
23 views

SiC Schottky power diode MATLAB simulation issue

Hi Everyone (first time poster), I am modelling a 4H-SiC Schottky power diode in MATLAB and I have come into some issues with MATLAB when trying to make an I-V curve. I was reading this paper and I ...
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3answers
126 views

SI derived units: Another name for the Volt [closed]

\$ V = \frac{Kg \cdot m^2}{s^2A} \$ I know it's basic but I was having a hard time understanding the relationship between volts, ohms, watts, amps and ohms until I broke everything down into base ...
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2answers
108 views

Under what conditions does jw equal the laplace variable s in an electrical circuit?

Imagine I've got an electromagnetic actuator and solved the underlying differential equations. I got an solution for sinusodially excitation, as follows (just an example, no physical backround): $$G(\...
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2answers
42 views

Voltage Drop Across Wire With Fixed Load Wattage

I am looking for an equation to calculate DC voltage drop across wires that run a distance, with a switching regulator and fixed load at the end (a known wattage). Here are the specifics: The power ...
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1answer
59 views

Calculating amperage in a current source

How do I determine the amperage at "?" based on the selected resistors in this current source? Falstad Simulation I took a bunch of measurements from the simulation and plotted them. I know that ...
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1answer
73 views

Digital Signal processing-Sampled period

Please can you help me with exam test preparation. I have take the below past year exam paper. I want to know if I am on the correct track and my answers are correct. x(t) = cos(50.pi.t + 30) ...
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0answers
39 views

What does K(k) mean in a transmission line equation

I'm reading through a book I have about transmission line structures. They frequently use the math: $$\frac {K(k)} {K(k')}$$ For instance, characteristic impedance: $$Z_0 = Constant \cdot \frac 1 {\...
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2answers
133 views

Fourier transform of \$x(t) =t^2e^{-|t|}\$

I have to find the Fourier transform of this function. (- sign exists BEFORE modulus). I thought of using this standard result. If I split this fourier transform into this will it be correct ...
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1answer
191 views

How to properly describe a Math Equation in Verilog to be synthesizable?

I have not been able to find a book or information in internet, about the correct way to describe a Math Equation in Verilog. With the correct way I mean for example, how to analyze the equation and ...
2
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1answer
79 views

Find dBm and watts of the attenuator?

The question says "A signal of 40 dBm is passed through the first attenuator. The first attenuator has a gain of 1. The second attenuator has 20 dB output. Find the dBm and watts This is what I tried ...
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2answers
75 views

How is the solution for \$\alpha\$ and \$\beta\$ current gain of a BJT derived?

I'm just an enthusiast, and not too good at maths; I'm exploring constant current source circuits, in doing so I came across two equations for BJT current gain: Could someone help me understand how \$...
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1answer
59 views

Quick question about a closed loop control system

Using above loop, we see that \$ \dfrac{y(s)}{r(s)} = \dfrac{p(s)c(s)}{1+p(s)c(s)} \$ and \$ \dfrac{e(s)}{r(s)} = \dfrac{1}{1+p(s)c(s)} \$ (well known results) Why is that: If the close loop ...
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1answer
67 views

Good book references for physics and math for electronics [closed]

Next year I'll join an engineer school in Dijon, France in the field of Electronics (Embedded Systems). I am currently taking a 2 years general IT education and my main problem is that I am very bad ...
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1answer
35 views

Simple problem with phasors

I'm trying to solve the following question (a): According to the solutions manual and wolfram the answer is: http://wolframalpha.com/input/?i=%28%285-6i%29-%282%2B8i%29%29%2F%28%28-3%2B4i%29%285-i%...
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2answers
102 views

Why is this second order system difficult to control?

Why is system of the type $$T = 1/(s^2 - 1)$$ Difficult to control using standard control methods? When I look at frequency plots, it doesn't seem to give me any important information as to why ...
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1answer
66 views

Function to Simulate Realistic Waveform

I need to simulate a realistic signal voltage triangle waveform in Mathematica. I know that a real waveform won't have sharp corners, but I don't remember exactly what a real triangle wave looks like....
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2answers
116 views

Control theory: is there any actual application for D in ABCD matrix?

Recall that a LTI state space of a dynamical system is given as: Is there any actual purpose for D in the output equation? If D was not zero, it would mean that the output is "directly" ...
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1answer
134 views

How to calculate capacitance and resistance for this simple A.M. radio?

\$v_i\$ is the A.M. signal, \$v_o\$ is the modulation wave. How do I calculate the optimal capacitance and resistance, for a given carrier wave frequency? If there isn't necessarily an "optimal" ...
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2answers
237 views

Designing voltage summer without op-amp

The above circuit is from Operational Amplifier Adder. Now remove feedback resistor and op-amp, and get the output. From the answer of the question, I know how the end result for Vout would be, ...
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1answer
165 views

How calculate standard deviation of ADC histogram for rms noise analysis?

Some papers from Analog Devices (like this one - page 2) and other sources indicates that the rms noise of a histogram plot of an ADC output can be found by calculating the standard deviation of the ...
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3answers
240 views

Collector current vs. temperature

In The Art of Electronics 2nd Ed. it is said that: The Ebers-Moll equation is $$I \approx I_s(T) e^{\frac{V}{25 \, mV}}$$ and the change of voltage with temperature at constant current is $$\left. \...
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1answer
461 views

Is there a way to Divide two 8 bit number in PIC 18fXXX assembly language not C?

I Can easily do the division in C of PIC micro controller. But is there a way to divide two number stored in two 8 bit registers. For example look at this code. I have to do it in PIC assembly for 8 ...
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2answers
72 views

Control: what is the proper justification that you can't just make the output equal to the input if the system produces unstable output

Suppose we have a signal, it goes into the plant and generates an unstable response, a common question then arise at that point is why can't we just set our output to a "hard-coded" input. Think of ...
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3answers
87 views

How can the FFT analyze a wave in which the components are changing?

Based on what I've read about Fourier Transforms, it seems that they are designed to work on waves whose components are constant. For example, a simple square wave is \$\sin(\theta) + 1/3sin(3\theta)...
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1answer
102 views

Distinguishing between FIR and IIR filters from transform function

I was good at this but unfortunately I have forgot almost everything... So the question is what are the steps to tell if a transform function is for IIR or FIR filter: $$H(z) = \frac{z^3+5z^2+3z+1}{...
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2answers
1k views

Positive feedback and virtual short in Operational Amplifiers

Can anyone please explain, with sufficient mathematics, why the virtual short concept is not applicable to an operational amplifier in positive feedback.
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1answer
98 views

Return Loss \$ (S_{11}) \$ Equation for a nth-order Butterworth Filter

I need a closed form equation for the return loss \$ ~S_{11}~\$ of an n-th order Butterworth low-pass prototype filter. I am designing a high power RF (lumped element) n-th order Butterworth bandpass ...
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1answer
139 views

So how do control engineers control nonlinear plant with exponential output?

Say that a system (circuit, pump, population model, etc.) has a exponential output of the type $$y = ae^{bx}$$ What do control engineers do in order to achieve control objectives such as tracking and ...
2
votes
2answers
989 views

Low Voltage AC Smoothing Capacitor Calculation

I have a 9V AC source which will have a max load of 100mA. I'm trying to figure the value of a smoothing capacitor with less than a 10% ripple. I don't have a scope or else I'd just try a bunch out. ...
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1answer
40 views

Complex multiplication identity

From my EM theory book: I have the solution for this problem, but I don't even understand the first step. How does V = r+jx => v(t) = rcos(wt) - xsin(wt)??
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1answer
86 views

Control Engineering: Model parameter estimation for a motor which will be under various loads

I am creating a closed loop controller for a motor which is part of a robotic arm. I give it a required angle, the controller calculates a control input, the motor moves, a pot feedbacks the angle, ...
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1answer
183 views

Control Engineering: Why are the Equation Error and Output Error different?

When modelling a system you must first estimate the form of the transfer function (order, time delay etc.), and then estimate the parameters (coefficients for the transfer function). A common way to ...
5
votes
2answers
120 views

How come you cannot determine the capacitance of a MOSFET gate based on the other supplied values on the datasheet?

Conjecture If it's the case that $$ Cg = {Qg \over Vg} $$ It must be the case that $$ (Ciss + Coss + Crss)Vg = Qgon $$ But it turns out that it is not. I don't understand what I'm missing. I ...
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1answer
176 views

Half Adder and Two Function, A Contest Questions?

I ran into a 2013 contest question on computer-science filed. What is the following True about F and G function. (The output ...
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2answers
102 views

Required math for setting up a laser diode

I'm new to electronics and come from a software background. Recently I got a laser diode that I would like to use with my arduino. The manufacturer says it is 5mW and draws 2.8-5.2V. I'd like to ...
3
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1answer
304 views

adding two 64-bits number with m-bit carry ripple adder and multiplexer, a questions?

I ran into a question from computer architecture class. The professor says that for adding two 64-bit numbers A and B we use m-bit carry ripple adders and multiplexers such as following: and that ...
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2answers
575 views

Understanding use of accelerometers to measure angular (rotational?) accelerataion

Imagine this: A rod is attached at one end to a rotating shaft. So, as the shaft rotates from 0 to 90 degrees back-and-forth (in the xy plane), so does the rod. My goal is to measure the instantaneous ...
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2answers
904 views

How do electrical engineers actually apply control theory in real life?

I am currently taking a course in control theory. In control theory the system or impulse response is usually an algebraic expression in Laplace domain. Much of the work done in school is to find ...
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1answer
278 views

Calculating the gauge of wire required for the secondary in a Tesla Coil

I am looking to build a small Tesla Coil at home with limited supplies. I am reasonably confident (well.. as confident as a biologist can be!) with my calculations so far, however I have hit a mental ...