Questions tagged [theory]
Theory is a contemplative and rational type of abstract or generalizing thinking, or the results of such thinking. Depending on the context
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Unit of integral windup reset parameter?
What is the unit of integral windup reset parameter? Is it the same as the unit of time, seconds?
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Behavior of BJT collector current in saturation [closed]
Let's assume that we have NPN BJT with absolute maximum rating of collector current = 1A.
Let's assume that we have separate power supplies for base-emitter and collector-emitter.
The collector-...
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Diode Power Dissipation
I am having trouble solving this PD question. I feel like it’s straight forward but I can’t seem to get the correct answer. I was curious if I could get help from the community.
Question: A p-n diode ...
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Better to use low ESR or high ESR caps?
I'm replacing the old filter capacitors on Marshall guitar amp and I was wondering if I should use low/non-low ESR caps for this.
As my understanding is (which is neither deep nor correct probably) ...
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Definition of a short [duplicate]
I know what a short is, or I think I know. Well maybe I don't.
If two wires from a power source are crossed - it's a short. If a component is working normally - not a short. If the component however ...
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Antennas Far field radiation pattern
I want to understand this Far field graph of an antenna generated in CST, from the picture:
Is this a good radiation pattern?
If yes, then how?
How to explain the graph?
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Higher Resistance Measurement on Wet Tongue than Dry Tongue?
I'm trying to start learning about electrical engineering as a hobby. I'm reading from a book right now, and it suggests using my multimeter to measure the resistance of my tongue while it's wet and ...
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Estimating self-discharge rate of ceramic capacitors from datasheet values DF and ESR
I'm trying to make an estimate for self-discharge rate of a typical small capacitor, such as 0.1 uF ceramic capacitor. Horowitz and Hill says "A better measure of loss at low frequencies is ...
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Define the expression by the waveform [closed]
Could you explain how to define the expression for the dead time \$\theta\$?
$$f_{1}=\frac{2}{2\pi }\int_{\theta }^{\pi -\theta }{V}_{in}\sin(\omega t)d\omega t
$$
$$f_{1}=-\frac{2{V}_\text{in}}{2\pi ...
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Solar Array Theory Misunderstanding
I am new to solar panels and I understand their is a lot more physics involved but I am trying to understand this basic concept. Wherever I look it is told that PV panels add Their voltage in series ...
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Need help to find the natural response of an RC circuit
Here is the question I am trying to solve:
I am stuck with the point that I am not sure Vo is found as -50v or +50v. Another issue is that Ic(t) is calculated by derivative formulas or another simple ...
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Need help to find Thevenin resistance and Thevenin voltage
Here is the question I am trying to solve(there are 2 things I need to find. These are Vth and Rth):
Here is my attempt: ( please check Vth if it is true )
I couldn't find Thevenin resistance at all
...
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Phase velocity expression
We have a \$\beta l\$ expression which is represented as phase velocity.
I know \$\omega_o=2\pi f\$.
What is the exact expression for phase velocity used in here?
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EE applications for parametric equations
I am trying to learn electronics, specifically audio amplifiers. I paused my study after realizing that my math skills (or rather my lack of math skills) were holding me back. I undertook a study of ...
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Why is base current needed after transistor is switched on?
If there already is a current flowing from the collector to the emitter, can’t the electrons just keep jumping over the PN junction?
Why does killing the base current make that impossible?
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How many transistors at minimum do you need to build a general-purpose computer?
I'm wondering what the simplest design for a general-purpose (Turing complete) computer is. To my surprise, I haven't found much on the web. Surely this is a known problem?
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Calculating thermal and current noise of InAmp opamp
I would like to calculate the thermal and current noise of the following circuit with OpAmp AD8428 device in the frequency range of 0.1 to 10 Hz (going to amplify basically very small DC). This is an ...
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Get voltage and current noise P-P values for 0.1 to 10 Hz from integrating the curve in the datasheet and comparing the results to the datasheets valu
Usually from OpAmps datasheets, you can get the RTI noise values for both current, and voltage noises exact RMS values for 0.1 Hz to 10 Hz. For a wider frequency range the noise density curve is flat, ...
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How to calculate break down amperage of wire based on length, resistivity, and cross sectional area?
For this question, I'm assuming the current is continuous, the shape of the wire is cylindrical, and the air is STP air.
(I bridged a fuse with a piece of soldering wire, and I'd like to be stupid in ...
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Preventing power LED runaway with voltage and PWM [closed]
Using near-minimum voltage for the LEDs to light up, and PWM to control brightness by not allowing the frequency/brightness to go above a certain point.
Comments are telling me its not okay to not to ...
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Electrical theory regarding load sharing
I am having issues understanding why raising frequency of one AC generator while in parallel with another causes it to pick up more load. Any help would be appreciated.
I operate with turbine powered ...
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Designing a common emitter audio pre-amplifier
I am trying to design and simulate a common emitter audio pre-amplifier using 2N2219 with characteristics based on industry standards (audio frequency response, etc. Corner frequency must be less than ...
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AC voltage and frequency as complex number?
For some software I am writing, I coded classes of electrical systems that receive a voltage and return the current response.
For the DC case that's easy: I pass a real number as argument, the voltage,...
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Why BJT thermal voltage can be not equal to kT/q in SPICE3
In SPICE, apart from effects such as basewidth modulation and base-collector leakage the collector current is given by the expression (according to the original SPICE2 PhD work)
But actually, ...
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How to show that all power in an RC circuit is delivered to the resistor
I am new to electronics and I've been working my way through the Art of Electronics. I've have been able to complete all the exercises up to this point but I have been struggling on this one. Right ...
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Why is my best placement of a directional antenna so weird?
I moved to an offgrid house with a 3G/4G repeater, with a short, enclosed directional antenna. It was wobbling and poorly mounted on an unstable wood plank at the base of a window, so I decided to ...
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What would a theoretical Group II, Group IV Transistor's Properties be? [closed]
This question is for more than a theory.
I would like to disprove that what I'm working on is not a Group II, Group IV transistor.
I know they CAN exist. I don't know why they don't exist or what ...
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Transistor analysis with 2 voltage sources
I want to calculate the DC currents of this circuit, and based on the superpostion theorem, I thought of ignoring Vqdc9 first, in order to calulate I2, I21 and I22, as shown in figure 2. After that, I ...
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What is the correct carrier concentration equation to use?
In this book I am reading, it gives the intrinsic carrier concentration as:
\$ n_i = \sqrt{N_c\cdot N_v} \cdot e^{({\frac{-E_g}{2*K*T}})} \$
While another book says the carrier concentration is:
\$ \...
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Why do we not see multiple or parallel DC PSUs?
A friend mentioned that his home router had blown its 12V PSU recently and had to be replaced.
That got me wondering - Servers and routers can have isolated dual PSUs for exactly this condition, but ...
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Is the amplitude of the sum of 2 transmitters of white noise at a given frequency greater than each individual transmission?
If you have two antennas \$T_1\$ and \$T_2\$ each broadcasting 10GHz Gaussian White Noise at the same receiver, each with an EIRP of say 20 dBW with a random phase offset between them, then is there ...
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Why is Line coding called "Line coding"?
Why is line coding also called digital base band modulation named "line coding" where does it come? and how is the name it to modulation
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About power dissipation of capacitors and inductors & I-V phase difference
For instance, The Art of Electronics (by Horowitz & Hill) states that
ideal capacitors cannot dissipate power, even though current can flow through them, because the voltage and current are 90° ...
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Difference between Message and Signal in Communication Theory [closed]
What is the difference between a message and a signal in Communication Theory?
It seems to me that often they coincide, is this always?
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Can someone confirm my derivation of the generalized power law from Practical Electronics, 4th edition?
I dont know how to use LaTeX, so I used Mathcha and took a snip from there.
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Matching via sizes to trace widths
Let's say I've determined a trace width (\$t_w\$) for a trace, and now I want to determine the size of a via on that trace.
My intuition is that to maintain the same amount of copper as the trace ...
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Why is BMC/k-induction used in RTL formal verification?
One popular approach for proving safety properties in formal verification of RTL designs is a combination of BMC and \$k\$-induction, which appears to stem from "Checking safety properties using ...
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Is there a method to convert a Butterworth response into Chebyshev and Bessel responses?
I wonder if once there is a completed/aproximated a design model of any of the responses mentionated, it can be operated mathematically (or there is a method/recipe) to generate the other responses?
...
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How is the slope of the frequency response of an analog active filter defined?
I have seen different types of filters, and different slope values at -20 db, -40, etc.
The literature says that the order define the slope, but how? How can it be mathematically justified?
For ...
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How/where does a generator + motor dissipate heat?
I've got a mystery that I can't wrap my head around.
A generator is generating 1 kW of electric power. The current goes through copper cables to a motor, which is consuming say 950 W of electric power....
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ESP32 Input Voltage Divider, Concept
Thank you for reading. I have read many other voltage divider explanations and calculators on this site as well as the web.
My application is using a voltage divider to lower a possible 5 V signal (...
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Will the net current drawn by a microcontroller equal the current supplied by it
Purely a theoretical question.
Consider a microcontroller whose only job is to turn 1 pin high and in the process the microcontroller supplies I1 current throught the pin.
But suppose we have to turn ...
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How to explain the strange results from this circuit (op-amp : differential amplifier?)
I have a differential amplifier. Problem of "gain" of the op-amp or "how it is wired."
I have simulated this as a voltage source controlled voltage (VofV.)
As a generic amplifer.
...
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Switching DC battery on ideal choke?
(Google translation). A switch is activated at the instant t = 0 in a series circuit containing a battery of voltage U (ideal) and an inductor L (ideal). I am in doubt with the answers I have found on ...
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Is it possible to implement one 8-way 1-bit multiplexer?
I'm sorry, but shouldn't 8-way have 3 bits in order to traverse every address? Anyway, I have here a problem, and I am not sure if my solution is correct.
The problem: Given the boolean expression
\...
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Is it possible to syntethize this Voltage Transfer Function?
I have the following voltage transfer function:
$$
H(s) = \frac {a s^4 + b s^2 + c}{p s^4 + q s^2 + r}
$$
Where \$a, b, c, p, q, r\$ are all real constants.
The only method I have been taught to ...
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Does the frequency response \$H(j\omega) \$ exist for system with unstable poles?
This question arose from a discussion between me and TimWescott in the comments here. The question is:
Does \$H(j\omega) \$ exist for systems with poles in the RHP (unstable poles)?
My own answer to ...
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How many newtons are there in one coulomb of charge?
Or, I should have said, how many newtons of force does one coulomb of charge exert? At a distance, presumably, of one meter? Since N/C is supposedly equivalent to V/m?
P.S. What are the values for a ...
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What does it mean that in a point Α of an electrical field the voltage is -7?
The title. I am really confused. Does it mean that you need to spend 7J of energy to move Q=1C from there to somewhere where V=0, does the Q you move matter? Does it mean you need to spend 7J to move ...
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Theory: Can power cables induce AC voltage in human body?
In a demo video (which I unfortunately can't share) a man makes the following setup:
Multimeter on 200 V AC settings with one pin in the ground socket of a conventional mains power socket.
Right ...
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