Questions tagged [math]

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

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-1
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0answers
25 views

how to subtract -13-4 using complements method? [on hold]

i came up to these question on my homework: Complete needed actions for these decimal numbers using complementary arithmetic, to get the right result. ...
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2answers
51 views

Difference between four matrices of state space?

I already know that there are two common types of representations used for mathematical modelling. One is transfer function and the other is state space. When dealing with state space representation, ...
2
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2answers
124 views

Question about the accuracy of integrated resistors

I'm studying the implementation of resistors in integrated technology. In particular the books deals with the accuracy of the obtained resistors. It says: Then it says: "We observe that the value of ...
0
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1answer
89 views

Efficiently calculate \$-x-y\$ using a single adder

I would like to know if there is an efficient way of implementing the operation \$-x-y\$ on an FPGA using only a single chain of adders or subtractors, roughly equal in length to the maximum number of ...
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0answers
49 views

How to calculate the rotation of stepper motor for winding a thread on a reel

A machine which can be used to wind the thread of exact length on a reel using two stepper motors, one for rotating the reel(Ymotor) and other one is used for traverse back and forward(Zmotor). So ...
0
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2answers
88 views

please explain this fourier equaton

reference from here why are there 2 exponential terms on right side of equation in red box ? i know euler identity but why does ,the left side is trigonometry form when n=1 equal to exponential ...
2
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1answer
41 views

Trying to find value of two capacitors using resonant frequencies in three conditions, but wrong formula is derived

I was trying to find capacitance of two capacitors in the following way. Connect each capacitor individually to a same inductor and find resonant frequency in each case. Connect the same capacitors ...
0
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0answers
55 views

Diode sine wave shaper - location of break points

I'm attempting to generate a sine wave from a triangular wave using the diode breakpoint method where the sine wave is approximated by multiple straight-line segments. Where should the breakpoints be ...
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3answers
2k views

Implementing an absolute value function in C

I am implementing a function to find the absolute value like this: uint16_t absolute_value(int16_t n) { int16_t mask = n >> 15; return ((n+mask)^mask); } ...
1
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2answers
115 views

How to find the right smoothing capacitor for rectification circuit

I am creating a power supply which will need to convert the 24vac to 5vdc. I am thinking of using a rectifier to convert ac to dc, then a capacitor to smooth out the voltage, then an LM2596-5 to drop ...
0
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0answers
20 views

How to convert T matrix to Z matrix in two port network?

How can I transform a T matrix to become a Z matrix for a two-port network? I found the following conversion to get the T matrix from Z matrix from here : https://www.tutorialspoint.com/...
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0answers
66 views

Find the transfer function of an opamp circuit

I've the following circuit: simulate this circuit – Schematic created using CircuitLab I need to find the transfer function of this circuit. I did the following: $$V_+=\frac{R_1}{R_1+R_2}\...
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0answers
35 views

Cooling Peltier Maths

I want to construct a peltier cooling system. However, I have limited mathematical skills. Can I ask how to do the maths to calculate how much temperature differential can a specific peltier cool ...
2
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3answers
62 views

Class A amplifier - Transistor Q-Point calculation

Reference: http://www.learningaboutelectronics.com/Articles/How-to-find-the-q-point-of-a-transistor-circuit I am trying to understand this q-point calculation. I recently asked a question about the ...
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1answer
63 views

DC Analysis of Transistor Circuits - Double vertical line symbol

I have stumbled twice across this symbol || being used in the analysis of transistor circuits. An example can be seen at this address: http://www....
2
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1answer
72 views

Second order RLC circuit problem about signs

Consider this circuit. Which is a second order RLC circuit. The problem asks for value of \$\phi\$ from the initial conditions. I took the first derivative of the equation by hand but as you'd see ...
0
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1answer
71 views

Impedance load matching

So I've done this so far, and know one of the components is a 50ohm resistor. However I dont know where to go from here. How do i decide if its an inductor or a capacitor? This is a past paper exam ...
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2answers
96 views

Current in charged RC circuit

I've the following circuit: simulate this circuit – Schematic created using CircuitLab The capacitor is charged up to 10 V according to the following formula (when the switch is closed): $$\...
0
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1answer
84 views

Maximum safe working voltage of capacitors

The answer is 30kV. My method led to an answer of 41KV, where did I go wrong? I believe I cant just add the Vmax(s) at the end, but what would I do instead and why?
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0answers
58 views

Help with determining the open circuit voltage

Can someone go through why Vxy= -84mV? Given the values off VB=180mv R1=22ohms R2=68ohms R3=150 ohms. Many thanks
2
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3answers
87 views

Mathematical help with Wheatstone bridge

This is a homework, so I won't ask for a complete solution, but can anyone tell me how should I approach this? I've been sitting now for hours without any progress, all that I know is the answer ...
2
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2answers
68 views

Where did this useful matrix decomposition come from for Nodal Analysis?

Background The equations formed when finding the nodal voltages of a circuit can be expressed using nodal analysis as a square system matrix \$\mathbf{S}\$ (lets say \$m\times m\$ where \$m\$ is the ...
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1answer
76 views

boolean algebra question regarding how to simplify a 5 input circuit

Background: I'm teaching myself computer architecture because I do not have a technical degree and want to learn this even though my finances won't ever allow me to have a formal education. I am doing ...
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2answers
66 views

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 ...
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0answers
46 views

Differential amplifier solving equations for iDS

In large signal analysis of differential amplifier there are some equations to determine iDS. If we simplify it looks like that : \$ \large 2x^2+2kx+k^2-2\frac{l}{m}=o\$ Is there an easy way to ...
2
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0answers
23 views

Price as a function of load on an electric grid(City modeling)

Thanks for your time. First some context and the actual question is marked further down. Context: I am modeling a city as a complex adaptive system and am building a model of an electric grid to run ...
0
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1answer
71 views

There is no math for adding the functions of two parallel filters. Or is it?

I want to add two "parallel" functions. Each of them describes the frequency response of that individual filter. Put in other words, I want to see what the frequency response looks like when the two ...
0
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1answer
68 views

Clarity on dB SPL calculation

Based on this post, let me assume that I have a input source of 94 dB SPL / 1 Pa that a microphone is picking sounds from. The microphone has a sensitivity of -46dBV/Pa , this gives 0.005012 V RMS/ ...
0
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1answer
37 views

Discrepancy in my dB SPL calculations

Having read through this post I tried an experiment. I connected a Extech sound level calibrator to a Type 4189 microphone. The output sensitivity of the microphone is 50 mV/Pa,-26 dB ± 1.5 dB re ...
0
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2answers
60 views

Deriving Capacitor Current Equation

I understand that the current through a capacitor is given by the capacitance multiplied by the rate of change of voltage. I also understand that this leads to infinite impedance for DC and virtually ...
0
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2answers
87 views

Fourier series coefficient for sin(wt+theta)

Am trying to find the Fourier series coefficient ck for the following function \begin{equation} x\left(t\right)=\sin\left(wt+\theta \right) \end{equation} Here is my work \begin{equation} c_k=\frac{1}{...
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2answers
152 views

Finding the average power dissipated in a resistor

Well, I've a series RL circuit that is powered by a voltage source. The input voltage is given by: $$\text{V}_{\text{in}}\left(t\right)=50+\frac{400}{\pi}\cdot\sum_{\text{n}=1}^\infty\frac{\sin\left(...
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1answer
46 views

Transforming a supply power [closed]

For a recent project i need to power a certain element with .7 amps and 5 volts. my input power is 5 volts, but i need to calculate a circuit for decreasing current. I looked for answers on google and ...
0
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4answers
115 views

Sinusoids represented using Euler's formula notation, confusion

EM plane waves are represented using the equation (ignoring amplitude) $$E(x,t) = e^{j (wt - kx)}$$ They are also represented in this form: $$E(x,t) = \cos(wt - kx)$$ I want to get the electric ...
0
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0answers
57 views

How to calculate the current produced by a solar panel?

The equation for calculating current when given voltage and temperature is known as the 5-Parameter model ie. \$I = I_{ph} - I_o[\exp(\frac{V + R_sI}{nV_t})-1] - (\frac{V+R_sI}{R_{sh}})\$ Since this ...
0
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2answers
64 views

Graphical nature of signal energy

In signals, we learn that the energy of a signal is the integral of its square. E.g. \$E=\int_{-\infty}^\infty x^2(t) dt\$ We know that integrals are the areas under the function in a graph. But ...
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1answer
43 views

Explanation of 5 Parameter Model for Solar Cells

I am having a hard time understanding this equation, the 5 Parameter model for photovoltaic cells. \$I = I_{ph} - I_o[\exp(\frac{V + R_sI}{nV_t})-1] - (\frac{V+R_sI}{R_{sh}})\$ My goal is to apply a ...
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1answer
71 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
48 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
153 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
145 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
50 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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2answers
163 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
154 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 ...
-1
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2answers
4k 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
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3answers
182 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 \...
0
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1answer
145 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
56 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 ...
30
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5answers
15k 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
84 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, ...