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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Can an electric circuit do recursion?

Can an electric circuit do recursion? By recursion I mean any kind of recursion, tail, binary, nested, etc: http://www.sparknotes.com/cs/recursion/whatisrecursion/section2.rhtml By electric circuit ...
0
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1answer
63 views

Control theory: What is the physical interpretation of asymptotic stability

For Bounded Input, Bounded Output stability (BIBO), there is a very nice interpretation. All it means is that if for any finite signal the system produces a finite output signal, then the system ...
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0answers
34 views

dBm Conversion to Common and Differential Mode Voltages

This is probably a question with a very simple answer, but it's been bugging me. If I have a signal generator, and I set the RF output to say, +13 dBm with an arbitrary frequency, what is the common ...
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1answer
101 views

How to solve first-order RC circuit?

I've got a question, and I just keep getting myself confused when I try to solve it. The problem asks to find voltage and current and resistor currents transients (the switch is opened at t=0). ...
0
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2answers
45 views

Relaxation oscillator period

For an electronics project I am using a Schmitt Trigger relaxation oscillator. The equation for voltage across a capacitor in time t is $$V_c = V_s(1-e^{\frac{-t}{RC}})$$ My Schmitt Trigger uses a ...
0
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3answers
85 views

8 bit computer graphics [closed]

I'm working on learning how 8 bit computers work and operate. I know you can make a (tedious) microprocessor with a larg amount of logic gates and such, but how does it read graphics? I know this uses ...
4
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1answer
299 views

Caculating baud rate of Ethernet per wire

I'm trying to find the answer to what should be a simple question. How do I calculate the physical rate bits are transmitted on an individual Ethernet wire? I am interested specifically in 100 Mbps ...
2
votes
1answer
72 views

why ohmic losses increase with resistance?

Electrical newbie here. I'm trying to get understanding how is resistance involved with power dissipation (ohmic losses, eg. heating). Primarily I'm looking at Electromagnet coil, it says the losses ...
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3answers
73 views

How to convert noise to noise density in mic pre amps

I am trying to compare two low noise mic pres for the lowest noise, and I am looking at the TI1012 and MAX9814 MAX9814: ♦ Low Input-Referred Noise Density of 30nV/√Hz TI1012: Output Voltage Noise ...
12
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7answers
2k views

Why do LEDs have a maximum current?

So I understand that LED's have a maximum current (like 20mA for instance), but scientifically why is this? Using the water analogy it seems like a high voltage would be the thing that would mess up ...
0
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1answer
29 views

In adaptive signal processing, what does it mean for an arrow to go through a block?

For example, in this case the FIR digital filter has an arrow going through it. This is common in the signal processing comunity but very unintuitive from a control perspective i.e. where is the ...
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1answer
54 views

AC Analysis Mindset [closed]

I'm just trying to solidify my foundational knowledge of ac analysis. So when approached with a basic circuit, lets say a RLC circuit, should my first instinct be to convert each group of components ...
0
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1answer
74 views

Help understanding the function of my circuit. (Bug swatter)

The important thing is the image below. I want to know how it works. Here's what I understand so far. First I'll identify the pieces: -The blue "packet" is a capacitor. Its a \$ 0.030 \mu F\$ ...
0
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1answer
132 views

Is electronic an exact science? [closed]

Whenever I read or watch any video tutorial about electronics most often it is said that electronic is not an exact science. But what I feel is if it is measurable then it should be an exact science. ...
2
votes
2answers
299 views

Op amp has a biased output

I'm designing an op amp circuit to amplify 20mV, 18kHz square wave up to measurable levels (~2-3V). Why is the output signal: Biased at ~400mV Triangular (high output capacitance? is that a thing?) ...
21
votes
8answers
6k views

Why do microcontrollers have so little RAM?

Maybe this is more of a perceptional problem, but it seems like microcontrollers have advanced by leaps and bounds in the last 20 years, in almost all regards, higher clock speed, more peripherals, ...
8
votes
3answers
2k views

Magnet that needs power to turn off? Inverse coil?

I have never heard of such thing. But it would really suit my needs. I'm inventing a device and during it's operation, it should be able to catch an iron object any time (with a permanent magnet). ...
0
votes
5answers
178 views

What would happen if an ideal voltage source was connected to an ideal wire?

I've seen it mentioned in discussion that an ideal wire doesn't exist (all wires have resistance), but even if it did, an ideal voltage source doesn't exist (all batteries have internal resistance); ...
0
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2answers
153 views

What is the difference between the substitution principle and Thevenin theorem?

The substitution principle (as seen in this book; in italian, sorry) Let A and B be any two part of an electrical network with voltage and current sources and only resistances, connected by ...
3
votes
4answers
429 views

Why don't infinitely many sinusoidals exist in an oscillator circuit?

A sinusoidal oscillator, takes the ambient thermal noise or any imbalance in the circuit as input and gives out an oscillation. This kind of oscillators are called to be linear. By the nature of a ...
2
votes
2answers
129 views

When is it theoretically possible to fit PCB circuit on x Layers (emphasis: x =1)

When is it theoretically possible to fit a given circuit on a certain number of layers? (Presumably PCB layers.) What is/are the name of the mathematics/algorithms that might determine this, or ...
5
votes
3answers
938 views

Theory question about “j” imaginary unit (AC circuit analysis)

I have just started to learn about AC network analysis and have some questions about "j" (or "i" on my calculator), the imaginary unit. My book doesn't go into a great deal about this, and jumps ...
7
votes
2answers
768 views

Why do op-amps keep amplifying?

I was reading an old copy of Horowitz and Hill's The Art of Electronics and I am trying to wrap my head around operational amplifiers in negative feedback circuits. As the book explains, as the ...
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votes
1answer
156 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 ...
0
votes
3answers
107 views

Why doesn't linear resistance scale proportionally with the square of length?

I have an in depth question about basic proportionality of resistance. Why doesn't it scale with the square of length? I ask this because what is causing the potential difference on two leads is ...
0
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1answer
44 views

Absolute and relative permitivitty

Principles of Electronic Materials and Devices - Hasap, pg: 585, he says: $$\epsilon_r = \frac{Q}{Q_0} = \frac{C}{C_0} = \text{relative permittivitty}$$ Then he says: It is important to remember ...
1
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1answer
199 views

Induced dipole moment and 'electronic polarization'

Principles of Electronic Materials and Devices - Hasap, pg: 586, he says: The induced dipole moment depends on the electric field causing it. We define a quantity called the polarizability a to ...
1
vote
3answers
378 views

Is there a maximum possible voltage?

This question got me to wondering if there is a maximum theoretical voltage. It seems to me there's a limit to how much positive or negative charge you could have--say, a container full of electrons ...
3
votes
4answers
523 views

Design vs reality and what to do when they differ

I've been trying to focus a bit more on Analog circuits lately and found that my design and actual results often don't match up exactly. An example is a Pierce oscillator I built a while back, the ...
2
votes
3answers
734 views

How can the SI unit of resistivity [Ωm] be interpreted?

The way I interpret the resistance \$R\$ of a resistor, which has dimensions \$ [\frac{\mathrm{V}}{\mathrm{A}}] \$ is: how many volts must be applied across the resistor to achieve 1 ampere of ...
2
votes
3answers
127 views

Voltage and Current along a Wire

In this question I am referring to this article. At first I was looking for a physical explanation of the fact that energy or the signal, respectively, travels much faster through a wire than the ...
-1
votes
1answer
100 views

Am I doing this right? (LED's to music)

simulate this circuit – Schematic created using CircuitLab I have been charged with designing and making a circuit that makes LEDs brighten or dim to an audio source. At the time I ...
3
votes
1answer
86 views

Resistivity and resistance. Permittivity and?

We know that resistance is dependent on both the materials resistivity and the geometry of the material. For a cylindrical or rectangular material the resistance is: $$R=\rho*\frac{l}{A}$$ where l ...
0
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2answers
117 views

At what resistance do I not see a voltage drop across a resistor?

If I have a circuit like this and measure the voltage drop across the resistor I get a value, regardless of what resistor I use: However, if I stick a piece of wood in there instead of the resistor ...
0
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3answers
82 views

Is it possible to have a continuous quantized signal or a discrete infinite precision signal?

When converting an analog signal to the digital domain I understand that one does two things. An analog signal is continuous and must be sampled in to discrete time segments (Discretization) The ...
10
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4answers
2k views

Where does U for voltage come from?

I believe in Europe the letter U is commonly used for voltage in (eg.) Ohm's law \$U = I × R \$. I think I understand where the letter V came from, commonly used in North America. But what's the story ...
1
vote
3answers
113 views

Biological 'Black Box' - how to test for underlying logic?

Firstly, I am a neuroscientist - so bear with me! I have a collection of connected brain cells (network) and a means of recording the electrical output, as well as manipulating the input to the ...
5
votes
1answer
323 views

What are the technical challenges to store electricity from lightning strikes? [duplicate]

I ask myself that question every time I watch a Tesla documentary. So, let's get some answers down so the smart ones can think about it and we can clean-up our environment. There is free electricity ...
11
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7answers
7k views

When people talk about a device “drawing” current, what do they mean? Why do devices under load “draw” more current?

In my (extremely rudimentary) understanding, the amount of current flowing in a circuit is determined by a) its resistance, and b) the voltage of the power source (voltage from beginning to end), ...
1
vote
1answer
98 views

Radios and Power [closed]

RF newbie here. Lately I've been experimenting with RF. I built some simple oscillators, managing to get a tank circuit working as well as buffering the 1 megahertz output of a tin can oscillator. ...
2
votes
4answers
187 views

Series/Parallel DC circuit analysis training issue

I'm blocked in this exercise. I don't get how I can compute R1/R2/R3 voltage. Here's the schema : simulate this circuit – Schematic created using CircuitLab So I was able to calculate ...
2
votes
2answers
218 views

Current divider rule calculation issue

I'm doing the exercises from Wisc-Online. This one I think they are really great to learn and practice and have already done a bunch of their practical trainings. But here I'm starting to be crazy. I ...
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vote
2answers
5k views

What does common mode voltage stand for in an instrumentation amplifier?

I was reading a text about instrumentation amplifiers. I couldn't find any easy explanation what really common mode voltage means and its importance.
1
vote
3answers
909 views

How does a domestic appliance “know” how much current to draw?

I have a small wall plug which takes 240V 50Hz AC from the mains, and can give me 500mA 5V DC. I suspect there is a transformer stepping the voltage down and a bridge rectifier converting the AC to ...
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votes
1answer
64 views

How would i go about finding Rl when rl is r3

How would i go about finding Rl :/ I'm so lost iv looked for examples and all they have done is confuse me
6
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4answers
244 views

Another question concerning transistors

I know it's been asked 1,000,000 times how/what/why transistors work and I feel like I've read every answer but I still struggle with the basics. The struggle for me is the difference between ...
2
votes
4answers
406 views

Resistors and the water analogy

The the most prevalent analogy for understanding electricity is the water hose one. I personally like this because it's very understandable but I have a question about how this works with resistors. ...
15
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6answers
1k views

Do electrical devices “take what they need”

One concept of electronics I have a hard time understanding is if things like motors, actuators, solenoids etc. use as much power as they need or what you give them. If a motor needs 12 volts and ...
0
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0answers
222 views

unity opamp - what it did for my digital volume control circuit

simulate this circuit – Schematic created using CircuitLab So I took apart the control pod for my 5.1 surround sound logitech speakers. Inside I found a 50k pot for the volume. At first I ...
4
votes
2answers
183 views

Differential equation into circuit and back - good book

I have had some electronics, but we only built our circuits and then measured the input / output signals with oscilloscopes... Today I found an interesting question on physics stackexchange where ...