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

Filter by
Sorted by
Tagged with
0
votes
2answers
59 views

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 ...
0
votes
1answer
40 views

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 ...
3
votes
2answers
63 views

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 ...
0
votes
1answer
52 views

Op-Amp Impdance Question

For the problem shown above since there is no current travelling through the input of the Op-Amp can we assume that the Op-Amp is acting ideally? And using this assumption can we ignore the output ...
1
vote
1answer
85 views

How to analytically find node voltages in a voltage doubler?

Given a voltage doubler circuit: simulate this circuit – Schematic created using CircuitLab You can figure out what should happen in stead state if \$R_L=\infty\$ and \$R_s=0\$. In that case, \$...
0
votes
1answer
39 views

Given the power spectral density, how do I calculate the bandwidth and total power of \$X(t)\$?

Given the PSD (power spectral density), \$S_x(f)\$, of a signal, how do you calculate the bandwidth and total power of \$X(t)\$? I think I have the bandwidth but how can I get the total power of \$X(t)...
0
votes
1answer
46 views

Blocking capacitor causing signal to go low in otherwise working amp/rectifier circuit

I'm making a simple amp > voltage doubler rectifier circuit to drive an lm3916 meter circuit and when simming to choose between JFET, BJT or OpAmp (just for my learning, I'm looking to a Jfet in ...
0
votes
2answers
63 views

Theory Question: Speakers don't work unless I poke soldered points with screwdriver

In case you couldn't tell by the title, I don't really have any idea what I'm doing with electronics. Something happened though, and I am really curious about it. Don't know how to ask it specifically,...
1
vote
1answer
30 views

Operative Definitions of Memory in Circuits

I've been studying Memristors (non-ideal) and some related circuits depending on pinched hysteresis of the IV for use in memory. I'm still puzzled by the lack of general framework for what constitutes ...
1
vote
2answers
66 views

What is Ethernet diff. pair referenced to between connector and magnetics

This is a little bit confusing part. I clearly understand that in ethernet cable fields are coupled between wires of differential pair. On PCB on IC/PHY side it is also known that differential pair ...
0
votes
0answers
37 views

A circularly polarized EM wave is perfectly absorbed by any interface?

According to the Fresnel equations, the effective reflectivity of an arbitrarily polarized electromagnetic wave is given as: $$ \Gamma = \frac{\Gamma_p + \Gamma_s}{2} , $$ where \$\Gamma_p\$ and \$\...
0
votes
1answer
49 views

Parallel LC circuit Q factor inductance role

I'm wondering why Q factor in parallel LCR circuit is proportional of C and inversely proportional to L according to the formula \$Q = R \sqrt{C/L}\$ completely lost here
-2
votes
1answer
63 views

What are the modern uses of SPI and I2C protocols [closed]

I have been using I2C and SPi for a few years now, but as I begin working with USB, I realize it is much faster. I still see devices with 2 MCUs that could potentially communicate faster with USB, but ...
1
vote
1answer
58 views

Meaning of the determinant of an ABCD transmission matrix

In a thesis, [1] I found the following statement: To determine [characteristic impedance and] dispersion relationships for an arbitrary reciprocal network having the transmission matrix $$ \begin{...
0
votes
0answers
40 views

Algebraic Data Type

I understand the concept of algebraic data types, but I don't see in what context they are useful or when they would be beneficial. When should I consider using them and how are they useful in ...
0
votes
1answer
102 views

Diodes and resistors theory

I came across a problem which I cannot calculate by theory. How does this circuit with diodes and resistors work? In the above diahram, I can calculate the current simply by subtracting the voltage ...
0
votes
1answer
74 views

Early Deadline First (EDF) scheduling in real-time systems feasibility test proof

I am trying to prove Theorem 6.2 on page 127 of the book Real-Time Systems by Jane W. S. Liu: http://www.cse.hcmut.edu.vn/~thai/books/2000%20_%20Liu-%20Real%20Time%20Systems.pdf It is based on Early ...
1
vote
1answer
105 views

How to deal with a negative resistor in Z parameters of a passive network?

This question is so basic but for some reason I am not seeing it: Assume an arbitrary passive 2-port network having only isotropic materials. This implies S21=S21 and Z12=Z21 (see https://www....
3
votes
3answers
467 views

Possible to control a transistor by BC terminals?

I'm thinking about a strange working mode: the CB part is forward biased and trying to control EC current by CB current. EB is reversed. May it work? Transistor is BJT.
2
votes
2answers
59 views

Why passive component has better drift characteristics than active components had?

I came across this paragraph in the classic reference Op Amps For Everyone by Ron Mancini where it says on the first page: Many attempts has been made to make a stable amplifier, but temperature ...
0
votes
1answer
26 views

Common emitter amplifier's \$R_C\$ breaks

What happens if the collector resistor breaks (its value goes to infinity) in a textbook example circuit? I assume that \$ I_C \$ hits zero, \$ U_{CE} \$ decreases until the transistor goes into ...
6
votes
7answers
2k views

Why is power of a signal equal to square of that signal?

Is there any logic as to why the power of a signal \$\mathrm{x(t)}\$ is taken as \$\mathrm{x^2(t)}\$? I searched everywhere and there's no clue. My professor told: "It's a standard result so shut ...
0
votes
2answers
92 views

Why does triode voltage drop change as a function of grid voltage?

Imagine a thermionic diode connected in series with a resistor \$R\$. The circuit is hooked up to a voltage source \$V\$. The diode conducts a certain current \$I\$ and \$\Delta V_\text{diode}\ + \...
0
votes
5answers
261 views

Is it possible to “hash” a circuit board?

I'll preface this by saying I'm a software engineer by trade and have very little EE knowledge. In the software world, one can take all the bits that make up a file and generate a hash for a file. ...
0
votes
1answer
61 views

Applying Thevenin's theorem between 3 points

I'm studying about transistor polarisation and got confused by this application of Thevenin's theorem, can someone please explain why eT is between B and M and why Vcc stayed even though it's not ...
0
votes
0answers
48 views

Type 1 surge protection: parallel or series?

Type 1 surge protection devices (SPDs) are installed at the outside edge of electric service, usually between the power meter and the meter base/socket, and protect the entire house. But how do they ...
0
votes
3answers
201 views

Energy Transformation in Flyback Transformers

I am trying to understand how is energy transferred as a current to secondary of flyback transformer. First due to the dot convention and secondary side diode, current will not flow in secondary and ...
1
vote
2answers
75 views

Why do I get such high values when calculating the power dissipation of MOSFET in boost-converter circuit?

I'm a hobbist interested in electronics so I don't have any "professional" training on that. Currently I'm trying to design a boost converter and now I'm stuck at some calculations. I wonder ...
10
votes
5answers
2k views

Is Gaussian noise equal to white noise?

If noise on a signal is randomly fluctuating in time domain around its mean following a Gaussian normal distribution (Gaussian noise), would this be equivalent to an constant intensity in the ...
1
vote
0answers
30 views

BJT Hre simulation problem

im having problems understanding the behavour of the hybrid parameter hre in the bjt AC model. im using the pi equivalent circuit to simulate the relation between hre and Ic (Dc value). i am not ...
2
votes
3answers
46 views

relation between transmission line & circuit impedance

What is the relation between the impedance of lumped components and the characteristic impedance of transmission lines? I have noticed that in some cases transmission lines are loaded with lumped ...
0
votes
1answer
54 views

Digital regulator for DCM Boost - How does it relate to duty cycle?

I really hope someone can help me here, I'm tearing my hair out trying to bridge the gap between control theory and electronics. My aim is to control a discontinuous conduction mode boost converter ...
4
votes
6answers
1k views

How do computers output a signal without an input? [closed]

I'm curious about how an output pin gets turned on at a low level when there is no input like pressing a button to complete a circuit. If you program a raspberry pi to turn on and off an LED how does ...
2
votes
5answers
475 views

Generalized Power Equation, Ohm's Law and Ohm's Power Loss?

I'll try to state my questions precisely as I can. I'm a beginner in Electronics and since I have a background in Physical Chemistry and basic Calculus, the book Practical Electronis for Inventors, ...
2
votes
3answers
263 views

What exactly does a resistor's tolerance rating mean?

I thought that I had this pretty much figured out over 30 years ago during my initial schooling, but various answers posted to a support forum of a major semiconductor manufacturer(name withheld to ...
0
votes
0answers
95 views

Why are 22pF capacitors so common? [duplicate]

I've noticed that many circuits use 22pF capacitors. For instance, the Arduino uses them to ground the oscillator pins of its AtMega328. Many tutorials call for exactly this value for simple circuits. ...
0
votes
1answer
105 views

Why don't commercial metal detectors clearly distinguish between iron and other metals?

I've read about how metal detectors work, and what I learnt here on EE.SE and other articles, the main principle is that ferrous metal will increase the inductance of the search coil, while non ...
3
votes
2answers
75 views

Why does lumped discipline not hold as dimension approaches operating signal wavelength?

I'm studying some basic introduction to the lumped matter discipline on my own. I completely understand where the first two constraints come from (i.e. lumped matter can only interact through their ...
1
vote
2answers
138 views

How can I tell if this boost converter is in continuous or dis-cont. mode?

I'm trying to intuitively understand a boost converter, so I've built a variable duty-cycle oscillator circuit that can go from 1kHz to 50kHz and allows me to adjust the duty cycle from 5-95% without ...
0
votes
2answers
96 views

Why do NPN/PNP transistors need to use doped semiconductors for the 'N' region?

By my understanding, as long as the P layers are properly doped (to have fewer free electrons), the electrons could not flow between collector and emitter until the P is given a satisfactory level of ...
0
votes
1answer
74 views

Can the 1D wave equation be recreated in a conductive wire?

I am ignorant of EE, but not the wave equation, so bear with me. The (scalar) wave equation \$d_{tt} - c^2d_{xx} = 0\$ describes the displacement (and velocity) of some medium through space and time....
3
votes
2answers
871 views

Can an induction motor be used to generate power?

Induction motors do not have magnets in them, instead the magnetic field the outer coils generate creates electricity, and subsequently magnetic field, in the inner coil. This means those motors need ...
3
votes
1answer
1k views

Why are circuit results different from theorised?

From the following circuit: I got the following results in comparison to my theorized calculations: Why were my result different to my calculations? Here is my calculations: Equipment used: ...
0
votes
2answers
136 views

Why is RMS used for P=VI (where there are no squares)?

I understand why RMS values are used for $$P = {\bar{v^2} \over R}$$ because \$\bar{v^2}\$ would be the "MS" so to speak, and then by square rooting we get the "RMS" (\$\sqrt{\bar{v^2}}\$), which ...
0
votes
3answers
118 views

Transistor Analysis

Here is a problem I saw as an example of transistor analysis: (hFE is 50) simulate this circuit – Schematic created using CircuitLab The process is simple, the guy assumed that the transistor ...
0
votes
1answer
57 views

Isolated circuits: can their reference voltages (GNDs) be at the same potential?

Suppose there are two independent circuits isolated from each other. If they are isolated, the impedance is very high between them (ideally infinite) and there is no current flowing from one to the ...
3
votes
3answers
190 views

Why doesn't electricty flow to earth ground when I connect my oscilloscope ground clip to a floating circuit?

There are two concepts I keep reading about that seem to be conflicting each other. Firstly, whenever there's a potential difference between two points, and those points are connected, electric ...
-2
votes
1answer
93 views

How can a resistor be given a positive and negative characteristic?

This question is not pertaining to a circuit, but to individual parts itself. If for any reason, i want to make a resistor have a positive and negative charge on its either ends, what would be the ...
0
votes
3answers
128 views

How to classify power electronics components in 2 main groups?

I'm working on preparing a course about power electronics, and with my basic search conclusions. I thought that if it's possible or acceptable to classify the power electronics components in 2 main ...
1
vote
3answers
185 views

What happens to a computer as it is cooled towards absolute zero?

What happens to the behavior of a conventional circuit using conventional components as it is cooled towards absolute zero? To make this question more relatable: What would happen as we cool a modern ...

1
2 3 4 5 6