Anonymous at Fri, 7 Feb 2025 01:24:09 UTC No. 16578054

>>16577993
I recommend these.
https://youtu.be/Kz6a-tDxiFU?si=dSKBZnkM-owmnND0

Good luck. When I first started circuits I thought they were actually hard but a few years of college gave me a better understanding of them. They really aren't that bad. I suggest you read about Thevenin's Theorem, Max power transfer, parallel and series impedances, source transformation, and stuff like that. Might be good to learn how to use a multimeter because everybody should really learn that.

Anonymous at Fri, 7 Feb 2025 01:45:14 UTC No. 16578065

>>16577993
Alexander-Sadiku is probably "The book" for circuit theory, but no book focuses on design problems as much as pic rel.
you really learn a lot by designing circuits.

Anonymous at Fri, 7 Feb 2025 02:27:02 UTC No. 16578087

>>16577993
Everything is a resistor divider. EVERYTHING.

Anonymous at Fri, 7 Feb 2025 02:34:56 UTC No. 16578091

>>16577993
>>16578054
>>16578065
I lost "Introduction to Circuits" on day 3 when current suddenly became a complex number for some fucking reason.
I decided that CS/EE was not going to be my thing.
Will these help fill that gap in my knowledge?

Anonymous at Fri, 7 Feb 2025 06:25:50 UTC No. 16578185

We still don't have an explanation for capacitance.

Anonymous at Fri, 7 Feb 2025 07:45:59 UTC No. 16578213

>>16578091
Not either of those two Anons, but a complex number is usually a sign that something is delayed behind something else. Magnetic fields created by inductors are, so to say, "ahead" of electrical fields, and then experience so-called "recoil", whereas capacitors temporarily hold electrical charge before releasing it. Resistors are neutral in that respect, meaning that they deliver current at the same time as they are supplied with voltage.

So basically, if you see something like a+bi, it means you're gonna get some current "ahead" of what the resistor would give you. If you see something like c-di, it means you're gonna see a bit of current coming "after" when you'd expect a resistor to deliver it to you.

The exact reason for the mathematical formulation isn't really explained until you see Fourier and Laplace transforms, so if you don't know them yet, just assume it's true and that it'll be explained one day.

Anonymous at Fri, 7 Feb 2025 08:42:42 UTC No. 16578243

>>16578091
complex numbers are too much abstraction and your reaction shows me right even I did suffer them till graduation

It comes back to fact to the euler identity
[math]\exp(ix)=\cos(x)+i \sin(x)[/math]
Now, alternating current is sinusoidally alterning
[math]I=I_0\cos(\omega t+\phi)[/math]
They just swap the cosine with imaginary exponential
[math]I=I_0\exp(i[\omega t+\phi])[/math]

and figures some meaningless meaning for the raising imaginary part

Anonymous at Fri, 7 Feb 2025 09:10:29 UTC No. 16578260

>>16577993

1) As >>16578065 said, Sadiku - Fundamentals of Electric Circuits is the gold standard as far as textbooks. You can find the book and sln manual on libgen

2) Shameless plug for this prof's youtube https://www.youtube.com/@rolinychupetin

he's won numerous teaching awards and I find with his videos things just click

don't trust the youtube electronics hobbyists they like making shit but have weak fundamentals

I like Griffith's book too, but for E&M try out Cheng - Field and Wave Electromagnetics. Also, Edminister - Electromagnetics has tons of worked problems

Anonymous at Fri, 7 Feb 2025 09:16:42 UTC No. 16578264

>>16578260
One more important thing that helped me:

Download ltspice. If you're confused why your simplified circuit isn't correct, it's such a valuable troubleshooting tool. Easy to use program that'll serve you well into your career. I use it on the job all the time.

Anonymous at Fri, 7 Feb 2025 11:28:38 UTC No. 16578320

>>16578185 bait?

Anonymous at Fri, 7 Feb 2025 17:07:31 UTC No. 16578569

>>16578264
Knowing how to check ltspice against an ODE solver against any other solution (hand calculation, Simulink, etc) is skill that comes in surprisingly handy. Just being able to model things at a ODE 101 level is like a superpower when you're out in the world with engineers that have forgotten all their coursework

Anonymous at Fri, 7 Feb 2025 17:25:50 UTC No. 16578586

>>16577993
Really any introductory linear circuits textbook will do.

As >>16578260 suggested, Sadiku is good. We used Reidel in my ECE undergrad program, which is also good.

Anonymous at Fri, 7 Feb 2025 17:39:59 UTC No. 16578593

>>16578243
I understand the frustration with complex numbers, but they really are invaluable if you do the work to understand it
I blame the way they are taught, we just learned them to solve diff equations where the solution contained sqrt(-1)
using complex numbers things get really smooth, things like Fourier series or any sort of periodic analysis becomes very easy to compute and deal with when you use complex exponents rather than sin and cos

check out chapter 2 of BOAS Mathematical Methods for a very good introduction

Anonymous at Fri, 7 Feb 2025 17:50:22 UTC No. 16578605

>>16578264
>ltspice
Is there a free simulator for electronic circuits with both analog and digital components? I remember using Multisim back when I had a student license for it, but never found a free equivalent to it.

Anonymous at Fri, 7 Feb 2025 17:55:02 UTC No. 16578607

>>16578605
Yes but nothing as good as ltspice or qspice or micro-cap. If I really needed digital and analog simulation on the same testbed for free I would look at the different flavors of QUCS.

Anonymous at Fri, 7 Feb 2025 18:35:35 UTC No. 16578641

>>16577993
∑v = 0
∑i = 0
v = R*i
v = L*di/dt -> V = jωLI
i = C*du/dt -> I = jωCU
You don't need more than that. The rest is EE bullshit to cope with the fact that they are filtered by the Maxwell's equations.

Anonymous at Sun, 9 Feb 2025 14:46:17 UTC No. 16580355

>>16578641
>>16578586
What would you say is the core of EE/ECE which you can't do without regardless of your specialty later

Anonymous at Sun, 9 Feb 2025 23:24:27 UTC No. 16580746

>>16577993
Here you go:
https://www.falstad.com/circuit/

>Kirchhoff's law
Nobody ever goes "ah, yes, this is true because of Kirchoff's law!".
EE requires a healthy amount of intuition. You should be able to figure out stuff like the Kirchoff laws on your own.

https://en.wikipedia.org/wiki/Hydraulic_analogy
Here's something that's very useful for beginners to build their intuition. Comparing circuitry to water flowing through pipes with special devices is an analogy that can be taken surprisingly far.

Eventually you'll find that circuits are EZ-PZ.

Anonymous at Mon, 10 Feb 2025 01:12:18 UTC No. 16580832

>>16580355
EE does a lot of shit. I'm a signal processing person, so I don't really use much circuits at this point but I do use a ton of control theory, signal processing, statistics, probability and linear algebra.

Every once in a while I need to do some transducer circuit model or something to generate samples, but for the most part circuits was really just a gateway to systems for me.

If you're someone that does the part of EE that actually works with electricity (either power systems, amplifiers or semi-conductors) then circuits stuff is really important.

Anonymous at Mon, 10 Feb 2025 22:34:03 UTC No. 16581941

>>16580832
If it's not too much to ask, do you mind posting the courses that build up to signal processing and their respective books?

Also, what does your day to day work look like? Any work you are or were particularly passionate about?

>meth student who needs some applied stuff to stay sane

Anonymous at Mon, 10 Feb 2025 22:40:34 UTC No. 16581952

>>16578320
Nope. we still don't have a proper understanding of what capacitance is.

Anonymous at Mon, 10 Feb 2025 22:46:29 UTC No. 16581956

>>16580832
>I'm a signal processing person, so I don't really use much circuits at this point but I do use a ton of control theory, signal processing, statistics, probability and linear algebra.
Wdym by systems and where does it fit with the above?
>Every once in a while I need to do some transducer circuit model or something to generate samples
What does the transducer take as an input(s) and what does it generate? Any chance we could see a schematic of your work flow?

Anonymous at Mon, 10 Feb 2025 22:51:42 UTC No. 16581961

>>16581941
1). Basic signals and systems course. The classic book for this is B.P. Lathi's Linear Systems and Signals. It's ODEs, a bit of babies first Fourier analysis, some linear algebra at the end, and some getting your feet wet with complex integrals.

2). Basic linear control theory. There's a ton of books that people use for this. My favorite is probably Norm Nose's Control Systems Engineering. This book covers all of the basics of PID feedback control, state variable feedback control, and even some graphical modeling of systems via signal flow graphs. Great book to introduce a lot of core ideas.

3) Digital Signal Processing. This is a topic that filters (excuse the pun) a lot of people because it is deceptively easy at first but requires an unbelievable depth of knowledge to really master. You can do the basics of z-transforms and sampling with algebra and some careful calculus, but when things start getting complicated you will very quickly find yourself in analytic complex function hell. The classic book for this is Oppenheim and Schafer's Discrete-Time Signal Processing. It's about 1200 pages and is enough to get your toes wet in almost every topic for the deterministic side of signal processing.

4) Linear systems again. Stop being lazy and do it right this time damnit (and by right we mean linear algebra and matrix exponentials). Linear Systems Theory and Design by Chen is good. Modern Control Theory by Brogan is easier.

5) Probability Theory and Stochastic processes. The ECE gold standard is Papoulis's Probability, Random Variables and Stochastic processes. You don't really need measure theory until you're really down in the weeds, but you should expect to get damn good at deterministic linear systems excited by continuous random variables.

6) Estimation Theory. It's least squares and kalman filtering. Either use Steven Kay's Fundamentals of Statistical Signal Processing vol. 1 or Bar-Shalom's Estimation with Applications to Navigation.

Anonymous at Mon, 10 Feb 2025 22:55:52 UTC No. 16581967

>>16581956
> Wdym by systems and where does it fit with the above?

In my case, mostly filtering of acoustic signals. An acoustic pressure wave propagates through a continuous lossy medium. We need to extract information from that pressure wave.

> What does the transducer take as an input(s) and what does it generate? Any chance we could see a schematic of your work flow?

Hydrophones turn pressure waves (mechanical force applied by the acoustic medium the baffle on the transducer is submerged in) and turns them into voltage. That voltage signal undergoes a pretty simple RLC circuit internal dynamics process. Can't show you exactly my workflow because that's a bit too revealing.

If you want a basic idea, take a look at Butler's Transducers and Arrays for Underwater Sound book on Springer and then Doug Abraham's Underwater Acoustic Signal Processing.

Anonymous at Mon, 10 Feb 2025 23:04:23 UTC No. 16581971

>>16581967
>>16581961
Based. Any suggestions as far as lab work go?

Anonymous at Mon, 10 Feb 2025 23:14:12 UTC No. 16581975

>>16581971
Physical lab work or computer lab work? In terms of computer work, it's pretty easy to learn the basics of systems modeling and try your hand at getting something like a synthetic measurement based tracker working in Python/Matlab etc.

Actual radar/sonar/lidar can get quite expensive. There are a ton of fine hardware details that end up becoming more of an art form than a science (try bench-tuning a hydrophone sometime to figure out it's frequency response. It's quite a finicky bitch).

Also, all of these things you learn in books. are first and foremost models, so do your best to not mix up the map with the territory.

There's no such thing as a linear-time-invariant system in meat space. There's no such thing as a Gaussian process in meat space. However, there are things that are well approximated in a "good enough for government work" kind of way by those modeling approaches.

Hell, the most "rigorous" of all of these models will end up requiring an asymptotically growing amount of physical constant coefficients that you'll literally never be able to acquire anyways.

That's not to say don't try to have the most rigorous approach you can have, but don't get discouraged if your direct path laser optical sensing simulation doesn't work as well with your Arduino as your simulations.

Anonymous at Mon, 10 Feb 2025 23:14:27 UTC No. 16581976

>>16581967
>If you want a basic idea, take a look at Butler's Transducers and Arrays for Underwater Sound book on Springer and then Doug Abraham's Underwater Acoustic Signal Processing.
Do you work for the Navy?

Anonymous at Mon, 10 Feb 2025 23:18:03 UTC No. 16581979

>>16581976
Something like that, but not exactly. You're in the right genre of nautical nonsense.

Anonymous at Mon, 10 Feb 2025 23:36:54 UTC No. 16581987

>>16581961
I assume these are the courses you take as specialization once you did the core of EE, correct? Have you found any use for the core courses besides the aforementioned circuits? e.g. electronics

Anonymous at Mon, 10 Feb 2025 23:44:12 UTC No. 16581990

>>16581987
My undergrad program split into specialization basically as soon as your junior year started.

As far as general EE, our "general" curriculum everyone took was the following:
1) linear circuits
2) transistors and microelectronics
3) EM fields/waves
4) Signals and Systems
5) Control Systems 1
6) digital logic systems and digital integrated circuits
7) modern power systems
8) semi-conductor architecture/chemistry

The rest was all either gen-eds (math, physics, chem etc.) or specialized courses.

The only stuff I've really used any of from my "general courses" (aside from the systems ones) are the linear circuits, a bit of digital logic from time to time, and very basic EM/RF for radar. The rest is all basically just systems and applied math focused work.

Anonymous at Tue, 11 Feb 2025 00:03:46 UTC No. 16582001

>>16581990
Thanks anon, you should do a /dspg/ once in a while and post interesting stuff, but for me, it will probably way above my head as I'm starting with electromagnetics and circuit analysis.

Anonymous at Tue, 11 Feb 2025 00:13:29 UTC No. 16582007

>>16581967
Do you use machine learning in your line of work? Did ML kill demand for DSP engineers?

Anonymous at Tue, 11 Feb 2025 00:21:57 UTC No. 16582014

>>16582007
> Do you use machine learning in your line of work?

Yes. All the time. Using machine learning for signal detection, target tracking, etc. Is a massive area of research. In fact, machine learning methods like expectation-maximization and support-vector decomp have been a part of "classical target tracking" for at least 30 years now.

> Did ML kill demand for DSP engineers?

Nope. If anything it's actually increased recently. DSP engineering and ML go hand in hand in a lot of ways. A lot of the standard normalization and data reduction techniques used in ML came from statistical learning theory and statistical signal processing.

So long as you are trying to use a model to process data, you'll need a DSP person to 1) help you figure out what "typical data" is for your training, validation and testing, 2) help you detect anomalies and weed out confounding, 3) determine your information limits and analytical targets (what is your lower bound for estimation error performance, regardless of the model used?), 4) filter and normalize to optimize training generalization/scaling.

Anonymous at Tue, 11 Feb 2025 02:41:22 UTC No. 16582090

>>16577993
I think Purcell covers some circuit theory

Anonymous at Tue, 11 Feb 2025 04:41:54 UTC No. 16582165

>>16577993
https://gtuttle.net/circuits/practice.htm
Some good stuff on here, you can click into any topic you need practice on and then refresh it to get a new problem. There's plenty of good circuit simulators out there too, I recommend picking one and then recreating circuits that you like or struggle with. You can change the different values on them, practice solving the answer, then use the simulator to check your answer.

Anonymous at Tue, 11 Feb 2025 07:59:01 UTC No. 16582259

>>16581952 bait?

Anonymous at Tue, 11 Feb 2025 08:42:42 UTC No. 16582294

I'm guessing you're not coming from a math background but if you know anything about reversible Markov chains then there's an equivalance to circuits that I found very useful

Anonymous at Wed, 12 Feb 2025 12:17:17 UTC No. 16583558

>>16577993
Nobody recommended the picrel masterclass, what a shame.
Also has one of the best appendices

Anonymous at Wed, 12 Feb 2025 12:18:55 UTC No. 16583561

>>16583558
Fuck cannot upload pic. It's Basic Vircuit theory by desoer

Anonymous at Thu, 13 Feb 2025 12:29:14 UTC No. 16584687

>>16583561
basic vicruit theory?

🗑️ Anonymous at Sat, 15 Feb 2025 15:57:25 UTC No. 16586797

to the first page

Anonymous at Sun, 16 Feb 2025 06:24:32 UTC No. 16587632

>>16582294
go on

Anonymous at Sun, 16 Feb 2025 08:09:11 UTC No. 16587670

>>16587632
well I'm not going to explain it as well as as by saying to look at section 3.3 here https://www.stat.berkeley.edu/users/aldous/RWG/book.pdf#page=67.59

It works for any resistances that you want to put on a graph but if we say every edge has resistance 1, then this analogy tells you that the resistance between a point and infinity on the 3D lattice is finite while on the 2D lattice it's infinite--just because the random walk can walk to infinity without returning on the first graph and not on the second

Anonymous at Mon, 17 Feb 2025 02:48:17 UTC No. 16588683

>>16577993
How come no one asks about analog/RF chip design? It's so overlooked in these woods.

Anonymous at Mon, 17 Feb 2025 02:58:12 UTC No. 16588690

>>16588683
Analog is expensive, more difficult, and often unreliable. If you design around digital systems, you have very little ambiguity for the signal. For the most part, a transistor is either in saturation or it is below the threshold. You need a bit more redundancy, but lets you do things like design reliable pseudorandom sampling (as you really have removed almost all of the meaningful randomness via the redundancies in the memory design) or reliable high precision computing.

Now, replace that with analog. The fundamental dynamics of your calculations are continuous in time and amplitude (meaning you don't have quantization or sampling issues to deal with) but your numerical coefficients of your system are dependent on things you can't properly measure or know. Your resistances, capacitances and inductors for whatever filter design you use will be dependent on changing temperatures, relatively delicate materials, and the condition of the connections/ground.

These will not be "off" if things start having problems (e.g., a resistor gets too hot and gets damaged). Your only way of knowing is suddenly the frequency response of one of the internal filters changes and becomes less resistive (and potentially unstable if it's in a feedback loop). Good luck diagnosing that problem reliably with a high information density design like a modern logic chip.

Anonymous at Mon, 17 Feb 2025 03:02:16 UTC No. 16588698

>>16577993
At this level all you need is Current & Voltage law.
You model Capacitor & Inductor as resistors, whose resistance is a function of resistance.
Theres a lot of problem solving to get through which honestly you can intuit out; just do a bunch of it.

When you get to transistors & larger scale circuits it gets more difficult.

Anonymous at Tue, 18 Feb 2025 07:06:34 UTC No. 16589903

>>16588698
>whose resistance is a function of resistance
were you meaning to type "a function of frequency"?