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Questions tagged [math]

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

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1answer
46 views

How to calculate the transmission distance from satellite to earth (How to understand the formula) [closed]

I have this question in one of my tutorials and I cannot seem to find clarity in the question - I am trying to make an algorithm to do this all automatically but I need to understand the formula I ...
0
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0answers
43 views

RLC circuit with intial conditions

The circuit I have is given by the following schematic: simulate this circuit – Schematic created using CircuitLab I know a few things: The current in the circuit at \$t=0\$ equals \$\text{I}...
0
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2answers
67 views

Connecting the following structure of multipliers and adders in an elegant way in verilog

I am attempting to write a synthesizable verilog (or Systemverilog) module. I also want to make the modul parameterizable, which has presented a problem when trying to connect the following structure ...
1
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1answer
41 views

Compensate centrifugal force in accelerometer measurements

I'm working on a project that includes counting the revolutions of a cylinder connected to an engine. This engine runs at a minimum of 5 revolution per second and a maximum of 9 revolution per second. ...
1
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0answers
34 views

How do you calculate average absolute value of a sum of sin functions with different amplitudes and frequencies?

I cant seem to find the answer anywhere. I remember there was a simple formula for doing this but I dont have the book with it anymore. Finding where the function is positive and where is negative and ...
0
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0answers
34 views

Solving a RLC circuit with a charged L and C

I've the following circuit: The input current is given by (the pules endures \$1/20\$ seconds and starts at \$t=0\$): $$\text{I}_{\space\text{in}}\left(t\right)=\max\left\{\mathcal{L}_\text{s}^{-1}\...
0
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2answers
103 views

Conversion from dBm to dB\$\mu\$V?

I am trying to derive the conversion from dBm to dB\$\mu\$V. So, please correct me If I am wrong. \begin{align} \textrm{dBm} &= 10 \log_{10} \left( \frac{P}{1\textrm{mW}} \right) = 10 \log(P) + ...
0
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1answer
70 views

Convert ADC value to real voltage

I want to measure the input voltage to my circuit. The input voltage is supposed to be anything between 7 to 35 Volts. I have a micro-controller with 12bit ADC. I am using a simple voltage divider to ...
0
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1answer
229 views

Calculate battery state of charge percentage

What is the correct formula to calculate battery state of charge percentage based on the battery type (12v, 24v, 48v and so on) and the current battery voltage. For example if I have a 12v battery ...
4
votes
3answers
123 views

Order of precedence for parallel operator

In electrical engineering the parallel operator || gives half the harmonic mean of two values. E.g.: \$R_1 \parallel R_2 \equiv \frac{1}{1/R_1+1/R_2} \$ But how should you compute \$kR_1 \...
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1answer
54 views

Control Theory Integrator Phase Shift

Guess I should know the answer, but I can't come up with a good explanation. I always have to remember which sign cos and sin have after integration/differentiation. I usually do this by thinking of ...
0
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1answer
39 views

Finding current over controllable voltage source using nodal analysis

I have the following circuit: Let me explain the diagram a bit first: I0 is current in that direction, V0 is voltage and 2 V0 is also voltage times two. V1, V2, and V3 are my nodes. The 'S' by the ...
29
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5answers
11k views

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 ...
1
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1answer
55 views

Finding the fourier series coefficients of the signal $$1+\sin (\omega_0 t) + \cos (\omega_0 t) + \cos (2\omega_0 t + \pi / 4) $$

I have come across this question that asks to find Fourier series coefficients of the following signal. $$1+\sin (\omega_0 t) + \cos (\omega_0 t) + \cos (2\omega_0 t + \pi / 4) $$ In my intuition, ...
0
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1answer
57 views

Control Theorie: Drawing Transition Matrix Trajectories

Given a transition matrix like e.g. $$ \phi(t)=\begin{bmatrix} e^{-3t} & 0 \\ 0 & e^{-3t} \end{bmatrix} $$ What is the analytical way of drawing x(t) for two given starting points? I only ...
0
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1answer
43 views

Multi phase vs single phase power factors

Are there any differences between calculating single phase and multi phase power factors? I'm open to general answers, but more specifically: If PF1=P/S, does PF3=(Pa+Pb+Pc)/(Sa+Sb+Sc)? Does ...
0
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1answer
36 views

2D Positioning Localization

I have a robot. My robot has three main sensors one is a gyro from which i can get my yaw, pitch, and roll. I also have an encoder in the x and y axis. How can I use these sensors together to reliably ...
2
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2answers
71 views

In a Wilson mirror, does Q3 need to have the same beta to cancel the base current error?

I'm learning about Wilson mirrors in the Art of Electronics Third Edition (pg. 102). It shows the following circuit: simulate this circuit – Schematic created using CircuitLab It then ...
0
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0answers
25 views

Find vertical shock from IMU during inclination

The PCB can be mounted in any orientation and from this the firmware must calculate the vertical shock that it experiences. As it would be calculation intensive to calculate he vertical shock for ...
1
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0answers
49 views

Calculation of Euler angles. But gets a change (delta) in change and not a constant value

What I've done will now: I'm using an IMU (MPU6000) to calculate the Euler angles of an object and for this, I'm using Madgwick AHRS algorithm. The MPU gives acceleration due to gravity (a) about the ...
0
votes
1answer
42 views

What's oscillatory instability in the delay differential equations?

Does DDE’s stability depend on forcing term and ODE’s stability does not depend?If yes, then is frequency analysis of stability applicable only to DDE and not ODE? In control systems, we study ...
0
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2answers
96 views

Poles and Zeros of Two Pole Compensation

I am known with the basics of what poles and zeros of transfer function are and how to determine them, but I certainly don't know how to apply such poles and zeros to the gain curve, which describes ...
4
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5answers
140 views

Average of a periodic voltage

I know that this question is math related, but I still don't get why we can say the following formula holds: I've a voltage \$V:\left[0,\infty\right]\to\mathbb{R}\$ and \$V\$ is periodic with \$T\$....
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1answer
77 views

Digital Multiplication, Subtraction, Division Integrated Circuits?

Having a hell of a time finding ICs that offer multiplication, subtraction and division? Are these functions just a product of adders and not worth the fab?
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0answers
26 views

Finding root mean square of a periodic function with transient phenomenon

I've a electronic signal that is periodic after some time. Let's say in the first \$n\$ seconds the (transient phenomenon) can be described my the function \$f(t)\$ (for \$0\le t<n\$) and after ...
0
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0answers
54 views

Roll-off of a third-order active filter [duplicate]

I've a third order active filter, without zeros. I know that when \$f=0\$ the gain response is \$1\$. So the cutoff-frequency is located at: $$\left|\text{H}\left(\omega_0\right)\right|=\frac{1}{\...
2
votes
2answers
269 views

Roll-off of a filter

I know that the roll-off of a transfer function gain is given by: $$20\log_{10}\left(\left|\text{H}\left(\omega_2\right)\right|\right)-20\log_{10}\left(\left|\text{H}\left(\omega_1\right)\right|\...
1
vote
1answer
41 views

Why do the brightness, luminous efficacy and power of this lightbulb not agree?

A particular LED lightbulb has luminous flux (brightness) \$\Phi_{\rm v}=820\ \rm lm\$, consumes electrical energy at a rate of \$P=9\ \rm W\$, and has a luminous efficacy of \$\eta=83\ \rm lm/W\$. ...
1
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2answers
374 views

Role of complex number in electronics [duplicate]

Complex numbers contain imaginary numbers as we all know but often it is used for solving real life practical problems such as taking the impedance of a capacitor, inductor etc. Even in Signals and ...
1
vote
2answers
141 views

Does the resistor values used for opamp circuits come from the equations?

I've the following circuit: I used the LM741 as the opamp. The input resistance is \$2\cdot10^6\space\Omega\$, the output resistance is \$75\space\Omega\$ and the voltage gain is \$2\cdot10^5\$. ...
0
votes
1answer
134 views

RC step response equation derivation

So this isn't really a big question, but I really need to get something clarified from the derivation of the RC step response equation, which goes like this: $$V(t)=V_S+(V_0-V_S)e^{-\frac{t}{RC}}$$ ...
0
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0answers
48 views

Determine the frequency and on time of two coupled ne555

I've the following circuit: I use it as a voltage controlled pwm generator. My question is, how can I find the frequency and on time of the PWM. I tried changing all the resistor and capacitor values ...
1
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2answers
272 views

Current Consumption of ICs from Datasheets

newbie in electronics here and taking self study (don't have time to go to school anymore xD). i just want to ask, regarding the image below: it came from this datasheet: https://d3uzseaevmutz1....
3
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2answers
64 views

Why did my textbook use signal energy as a measurement of approximation error, instead of something else?

TL,WR: Why do we use signal energy as a measurement of an approximation's error, and not something "simpler" like the absolute value of the error? Background: I'm reading through my textbook for my ...
0
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1answer
2k views

Nichrome wire gauge calculation

I know what battery I wish to use (3.7 V 140 mAh which I can swap for larger mAh battery) I know what length of wire (3.5 inches or 7 inches depending on which ever would work better) I know what ...
1
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1answer
64 views

Question about the RMS value of the real input power

I've the following circuit: simulate this circuit – Schematic created using CircuitLab I know that the relation between the input voltage and the input current is given by: $$\begin{cases} \...
0
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0answers
255 views

Voltage function after a capacitor filter in a full bridge rectifier

I know that the voltage after a capacitor filter can be plotted as follows: But we can't say that the positive waves are across the resistor because a capacitor behaves in a DC circuit differently. ...
12
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7answers
2k views

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'...
2
votes
1answer
131 views

LC circuit with series diode (finding the linear average)

I've the following series LC circuit: Find the (linear) average of the current trough the diode. The ideal is a ideal component. The initial conditions in the circuit are equal to zero. MY ...
1
vote
2answers
88 views

Electric Field electrical charge

Hey i dont know how to solve this. Can somebody help me? In the two-plate arrangement shown in the sketch, there is homogeneous electrical field strength $$\vec{E_0} = -\vec{e}_y * 10\frac{kV}{cm}$$ ...
1
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3answers
449 views

Calculating total capacitance of a circuit

simulate this circuit – Schematic created using CircuitLab Question is, how to calculate capacitance of such a circuit. I made a schematic with resistors (because that i can measure) and from ...
1
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2answers
199 views

mathematical equation for parallel voltage dividers?

As a followup to my previous question it turns out there was more to it than I thought. It seems that between my voltage divider and the ADC on the ESP there is a second voltage divider to step down ...
0
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1answer
851 views

BLDC Calculation for Back EMF

I have a brushless DC Motor that i am considering buying from hobbyking.com with 2100Kv (RPM/v) i am trying to follow the equation on Wikipedia's motor constants page i have included the equation here ...
-1
votes
3answers
71 views

What research has been done on Smart Grid software agents that both cooperate and compete? [closed]

Background For my master's thesis in Applied Mathematics, I am looking for ways to apply game theory to problems related to the so-called "Smart Grid". I have found many papers in which all involved ...
1
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1answer
240 views

Calculating the magnitude of impedance

I am working on a project to model the electrical characteristics of a piezoelectric (PZT) and would like to get a sanity check to make sure I am going about it in a way that makes sense. So I am ...
1
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0answers
62 views

Is my millijoule (mJ) calculation correct?

My partner and I are reviewing our products compliance with IEC 60601-1 and need verification of our millijoule calculations. Our product outputs (up to) a 240v bi-phasic square wave, 240mA and ...
0
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2answers
69 views

Finding Voltage and Current across a capacitor. Will you check my work?

Question: Work: I have decided to approach this question using a differential equation for practice, but I keep getting an equation that doesn’t seem right. The reason I think this is because for ...
0
votes
2answers
1k views

AC RMS and DC average voltage

Imagine we're trying to get 120V output. For AC, we must have a source with a peak voltage of 169.7V to achieve an RMS voltage of 120Vac. (169.7V * 0.707). For pulsating DC, whether rectified by a ...
0
votes
1answer
87 views

Boundary conditions of the Electric field of a conducting transmission line

Solving Maxwell's Equations for the Electric Field of a linear-isotropic cylindrical conductor leads to the electric field being proportional to the Bessel function of the first kind (see below). ...
0
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1answer
45 views

Emitter follower augmented input current

Hello, I have this emitter follower augmented ( I think that's his name in english) but I don't know from where is the beta+1 on the Iin ecuation?