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

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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
136 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
62 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
205 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
96 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
80 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
33 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
38 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
102 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, ...
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1answer
52 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
79 views

Number of independent KVL equations in a circuit?

Could someone explain why, for a circuit with B branches and N nodes, the number of of linearly independent KVL equations for a network is: B-N+1 Thanks.
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7answers
446 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
92 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
130 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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vote
1answer
98 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 ...
5
votes
3answers
374 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
96 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
78 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 ...
0
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1answer
270 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 ...
6
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3answers
110 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
129 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
348 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 ...
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1answer
99 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
66 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
158 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 ...
4
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2answers
133 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
290 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 ...
3
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2answers
337 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
127 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
174 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 ...
2
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2answers
516 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
votes
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
124 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
628 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
346 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
273 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
287 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
182 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 ...
6
votes
2answers
7k 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 ...
2
votes
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 ...
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1answer
160 views

what type of electronics job would combine mathematics, electronic design and programming into one [closed]

There are quite a few different areas of jobs in the Electronics industry. We have Analogue, Digital, Embedded, Telecommunications, Control and much more. What I wish to know is that what job would ...
3
votes
1answer
820 views

Constant current source math - Using AD8276 differential Op-Amp

So I'm trying to implement a constant current source to conduct a specific measurement using a AD8276 differential amplifier. I'm trying got derive the equations my self for sanity check, and to give ...
4
votes
3answers
278 views

Solving this op-amp circuit

I would appreciate some help solving the following circuit. I've been trying for a very long time and can't get the same answer the book has. I'm trying to get \$ V_o \$ in terms of \$ I_{os} \$. ...
3
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1answer
229 views

Switches needed in an n-location multiway switching system

Wikipedia shows us we can construct a two location multiway switching system with two 3-way switches: They also teach us how to perform three location multiway switching with two 3-way switches and ...
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2answers
221 views

Basic circuit analysis - diferential equation

This is the circuit I got from an example in a book "Practical Electronics for Inventors", on page 48: How can one understand that \$0=R\frac{dI}{dt}+\frac{1}{C}I\$ implies ...
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1answer
690 views

How does one compute the ripple currents seen by a boost converter output capacitor?

Suppose one is designing a boost converter, with a known maximum current load, and a known inductance: The ripple current seen by the output capacitor is critical. If that current is too high, the ...
5
votes
1answer
1k views

How does one compute the ripple currents seen by a rectifier filter capacitor?

Suppose one is designing a full-wave rectifier bridge, with a known maximum current load, and a known input inductance. Assume three-phase for this example, though the same concept applies to ...