Art of Electronics - Study support

[alex_palvai]

Hi Everyone, 

Glad I found a place where i can find some like minded people . Happy to see all the forums and discussions here. 

I am a hobbyist in electronics who want to improve my knowledge and expertise in subject.  I started following Art of Electronics and LAB and managed to finish few pages in 1st Chapter.  I started studying since a week and progress has been relatively slow as i want to ensure i understand the concepts properly before turning pages.

I  am stuck in sinusodal signals  in theories of  physics , differential, formula's and trigonometry and would like to start my first question from this . How necessary is this knowledge to proceed ? Do i need to go back to math & physics , rehearse those and come back ?
 

[rstofer]

AoE tends to minimize the math.  If you have specific questions ask here.  Somebody will know the answer.

[munkeyman1985]

I  am stuck in sinusodal signals  in theories of  physics , differential, formula's and trigonometry and would like to start my first question from this . How necessary is this knowledge to proceed ? Do i need to go back to math & physics , rehearse those and come back ?

We can't read your mind to see if the needed information in there. If you took engineering in college, you might be stating this book at the same time calculus 1 and calculus based physics. Maybe that helps.

[GerryR]

There is no silver bullet, magic pill or the like.  You need the basics to advance.  If you just want to touch the surface as a hobbyist, there are many cookbook style texts available.  Math is essential, and there are a multitude of texts available with applications of calculus and trigonometry to electronics.  Get the specialized books geared to electronics.  My feeling is that if you master the math, the rest is a knock.  JMO.

[rstofer]

I am of two minds on the math thing.  First of all, electronics is applied math; simple as that!  It's all math and, yes, the math is important.  However...

Do I need to be able to derive the differential equation for charging a capacitor (Question 13 in the attachment) or just accept that it is correct and use the exponential equation just above and including Figure 7?  Let's face it, the derivation is pretty if you have the math but it's the resultant exponential equation that gets used every day.

http://web.mit.edu/molly/Public/circuits-b.pdf

Integral calculus is usually taught in the second semester of EE school assuming, of course, that the student had competence with Pre-Calculus before starting college and this isn't always true.  If they don't have competence, Pre-Calc is usually a two semester course so add a year to your graduation date.  Not paying attention in high school comes at a cost!

For the hobbyist, accept Figure 7, know the exponential result and be absolutely certain you know how to plug the numbers into a calculator.

Take 10k Ohms and 0.1 ufd.  Tau (the time constant) = R * C (R in Ohms, C in Farads) and this is a  number you need to calculate and you better get 1 ms (0.001 on the calculator).  Then when somebody says, what percent charge is on the capacitor at t = 1 Tau (or 1 ms) the result should be 63% - this is just an exercise in calculator operation but it is an important equation.  Assume Qf = 1

As to sines and cosines, you usually run across cos(wt) where the lower case w is supposed to be the Greek symbol for Omega.  It is pronounced 'cos omega t'.  You need to remember that omega = 2 * PI * frequency (in Hz).  It's just shorthand, EEs are a lazy bunch.

https://en.wikipedia.org/wiki/Radian_per_second

When you get to Kirchhoff's Laws with AC circuits, the arithmetic gets a little hairy.  I CAN solve the equations by hand but I don't.  MATLAB is my tool of choice but the free program Octave is a work-alike.  Maybe this will help, maybe it will just add to the overload:

https://www.amazon.com/gp/product/0982497008

What you need to decide is at what level do you want to know electronics?  The hobbyist is usually doing a cut and paste operation with minimal actual design.  Serious math may not be required.

A couple of my favorite resources:
For solving stuff:  www.symbolab.com
For graphing stuff:  www.desmos.com

[Wimberleytech]

I am of two minds on the math thing.  First of all, electronics is applied math; simple as that!  It's all math and, yes, the math is important.  However...

I have a similar mindset.
Being able to analyze a circuit in the S domain is important, but rarely do I need to do the same analysis in the time domain (where the work load goes up).  Even so, if I need to analyze something that has more than a couple of poles/zeroes, I will just shove the netlist into a symbolic solver to get the transfer function.

[rstofer]

I am of two minds on the math thing.  First of all, electronics is applied math; simple as that!  It's all math and, yes, the math is important.  However...

I have a similar mindset.
Being able to analyze a circuit in the S domain is important, but rarely do I need to do the same analysis in the time domain (where the work load goes up).  Even so, if I need to analyze something that has more than a couple of poles/zeroes, I will just shove the netlist into a symbolic solver to get the transfer function.

Does the average hobbyist even need to know there is an S domain?  Unless they get to filter design or control systems, I'm not sure how important that concept actually is.  Laplace Transforms and Fourier Series, good luck with that!  I don't even want to think about Field Theory and Maxwell's Equations.

But, yes, by all means, stuff the equations into MATLAB.  I got through college with a slide rule and I'm pretty sure I don't remember how I made it past the math.  Maybe that is why I have never played in the analog circuits corner of the electronics sandbox.  I have stayed in my little corner over in the digital domain.

As Bob Widlar (very famous analog circuits designer for National Semiconductor) said:

[Wimberleytech]

I am of two minds on the math thing.  First of all, electronics is applied math; simple as that!  It's all math and, yes, the math is important.  However...

I have a similar mindset.
Being able to analyze a circuit in the S domain is important, but rarely do I need to do the same analysis in the time domain (where the work load goes up).  Even so, if I need to analyze something that has more than a couple of poles/zeroes, I will just shove the netlist into a symbolic solver to get the transfer function.

Does the average hobbyist even need to know there is an S domain?  Unless they get to filter design or control systems, I'm not sure how important that concept actually is.  Laplace Transforms and Fourier Series, good luck with that!  I don't even want to think about Field Theory and Maxwell's Equations.

But, yes, by all means, stuff the equations into MATLAB.  I got through college with a slide rule and I'm pretty sure I don't remember how I made it past the math.  Maybe that is why I have never played in the analog circuits corner of the electronics sandbox.  I have stayed in my little corner over in the digital domain.

As Bob Widlar (very famous analog circuits designer for National Semiconductor) said:

I am an analog guy, so, yes I think in terms of poles and zeroes.  I dont know what an average hobbyist is but you may be correct.  The easiest way to know is to survey all of the questions on the Beginner board and see how many reference bandwidth, frequency response, poles, zeroes, etc.  That would be an interesting exercise.

[GerryR]

I don't think you have to be an expert at everything, but you should at least know what has to be used where, and then know where to look it up.  Will Rogers put it best, "Everybody is ignorant, just on different subjects."  So, in the areas you are lacking, know where to look it up.  I'm stuck in the middle between analog and digital and have done a fair amount in each area, but mostly related to the automation world involving sensors, signal conditioning, etc.  I have an extensive library, so when I get in trouble, I go to my references.  But, if I didn't have the initial exposure and understanding, how would I know what needed to be researched?  Like I said before, there's no magic pill, just good old fashioned hard work.  JMO.

[ebastler]

I am an analog guy, so, yes I think in terms of poles and zeroes.  I dont know what an average hobbyist is but you may be correct.  The easiest way to know is to survey all of the questions on the Beginner board and see how many reference bandwidth, frequency response, poles, zeroes, etc.  That would be an interesting exercise.

I have not done that exercise (and don't intend to do so), but can venture a guess:

You will find a fair share of questions about bandwidth, and some about frequency response. But hardly any on Laplace transforms, poles, and zeroes -- and the few you find won't be from hobbyists looking for help with a project, but from students looking for help with their homework. 

[rstofer]

I don't think you have to be an expert at everything, but you should at least know what has to be used where, and then know where to look it up.  Will Rogers put it best, "Everybody is ignorant, just on different subjects."  So, in the areas you are lacking, know where to look it up.  I'm stuck in the middle between analog and digital and have done a fair amount in each area, but mostly related to the automation world involving sensors, signal conditioning, etc.  I have an extensive library, so when I get in trouble, I go to my references.  But, if I didn't have the initial exposure and understanding, how would I know what needed to be researched?  Like I said before, there's no magic pill, just good old fashioned hard work.  JMO.

But to what end?  My point is that, as I see it, most electronics practiced by hobbyists seems to be related to using an Arduino and then realizing that everything that can be done with an Arduino has been done and it's on the Internet.  There are clearly exceptions...

A step up would be to understand Ohm's Law, Kirchhoff's Laws, Thevenin's Theorem and Norton's Theorem.  That is probably enough for most hobbyists at even a fairly advanced level.  They are not likely to be designing 3 pole filters.  At a minimum, Ohm's Law, in all its manifestations, needs to be understood from day 1.  We go nowhere with op amps without Kirchhoff's Current Law.  But these are just ordinary arithmetic, nothing esoteric.

You're absolutely right about resources.  I have a huge library but my real resource is Google.  All of human knowledge is on Google, all I need to do is come up with the right search string.

There's a lot of space in the electronics sandbox and people can move to a spot that is comfortable.  I like digital, the only reason I went to college was to learn digital and that's the portion of the sandbox where I play.  Can I go back and recapture what I learned about Laplace Transforms?  Sure!  But I would need an application that generated enough interest to bother re-reading my textbooks.  Of course, having MATLAB will make the actual work a lot easier.  I really don't like partial fraction expansion of polynomials if I have to do them by hand.

I should put in a plug for Khan Academy for math and the Electrical Engineering program at Khan Academy for the more focused stuff.  Khan Academy is free!  Or you can contribute - I do...  I highly recommend these programs!

For a fee, CalcWorkshop.com is excellent.  There is a free series on Limits just to show how the lecture series work.  It's a GREAT program!

Here is the Limits program:
https://calcworkshop.com/online-limits-course/

I highly recommend taking the entire program starting from wherever seems appropriate.  Jenn does a great job as an instructor.  She starts with Algebra I and works up through Differential Equations in 8 major blocks and about 450 videos!  If a person were to spend $150 for a year and they got through the entire series, it would work out to about $0.33/video.

All of the education required is right there in one very long program.  It isn't free but it is well worth the money.  Subscribe for a year and go through the program as fast or slow as you wish.  Education has never really been free.

BTW:  You may wonder why you even care about Limits when they are just a prelude to the derivative.  It turns out the concepts are actually useful in certain conditions when you have a discontinuity in a function and it can't be differentiated at that point.

[rstofer]

I am an analog guy, so, yes I think in terms of poles and zeroes.  I dont know what an average hobbyist is but you may be correct.  The easiest way to know is to survey all of the questions on the Beginner board and see how many reference bandwidth, frequency response, poles, zeroes, etc.  That would be an interesting exercise.

I have not done that exercise (and don't intend to do so), but can venture a guess:

You will find a fair share of questions about bandwidth, and some about frequency response. But hardly any on Laplace transforms, poles, and zeroes -- and the few you find won't be from hobbyists looking for help with a project, but from students looking for help with their homework. 

How Not To Blow Up Your Scope is another popular topic.  I actually like working on some of the homework problems.
I would think the poles and zeros would be over in the Projects forum, if they were to show up at all.  People who understand what these are probably don't need to ask.

[Wimberleytech]

OK.  I admit defeat.

[GerryR]

I don't think you have to be an expert at everything, but you should at least know what has to be used where, and then know where to look it up.  Will Rogers put it best, "Everybody is ignorant, just on different subjects."  So, in the areas you are lacking, know where to look it up.  I'm stuck in the middle between analog and digital and have done a fair amount in each area, but mostly related to the automation world involving sensors, signal conditioning, etc.  I have an extensive library, so when I get in trouble, I go to my references.  But, if I didn't have the initial exposure and understanding, how would I know what needed to be researched?  Like I said before, there's no magic pill, just good old fashioned hard work.  JMO.

But to what end?  My point is that, as I see it, most electronics practiced by hobbyists seems to be related to using an Arduino and then realizing that everything that can be done with an Arduino has been done and it's on the Internet.  There are clearly exceptions...

A step up would be to understand Ohm's Law, Kirchhoff's Laws, Thevenin's Theorem and Norton's Theorem.  That is probably enough for most hobbyists at even a fairly advanced level.  They are not likely to be designing 3 pole filters.  At a minimum, Ohm's Law, in all its manifestations, needs to be understood from day 1.  We go nowhere with op amps without Kirchhoff's Current Law.  But these are just ordinary arithmetic, nothing esoteric.......

What you say about Arduino is "cookbook engineering."  Having a more in-depth knowledge allows you to change the recipe and adds a little creativity to a design.  I have electronic cookbooks, as I expect most engineers have; they save a lot of time in a design process, but it would be a rare occasion for me to find a design that didn't need a "recipe change" to suit my application.  Without a more in-depth (not necessarily extensive) knowledge, I couldn't make these changes.  Of course, there are the unique project requirements where you have to start from scratch for the entire design, and cookbooks are of very little help.

I don't know how anyone can even be considered an electronics hobbyist without knowing the basics you describe in your second paragraph.  I would merely describe them as "kit builders."  That is evidenced by the types of questions I see asked when something they have built doesn't work.  But hey, if they are having fun, each to his or her own.     I have had to make a living at what I do.

[rstofer]

I don't know how anyone can even be considered an electronics hobbyist without knowing the basics you describe in your second paragraph.  I would merely describe them as "kit builders."  That is evidenced by the types of questions I see asked when something they have built doesn't work.  But hey, if they are having fun, each to his or her own.     I have had to make a living at what I do.

Regardless of labeling, if the hobbyist is having fun, that is sufficient.  If they need to know more, they can take a side trip and study up on a subject.  But it is clear to me that a lot of hobby projects can be built without differential equations or Maxwell.  There is no need for a 5 year degree just to play in the sandbox and they probably aren't making a living out of electronics.  For me, electronics has always been a hobby.  I spent a lot of time in school just to support a hobby...

[GerryR]

I think we are on the same page here!

[alex_palvai]

Thank you for all the responses. Appreciate suggestion from rstofer about khan academy.  Few guesses are right, i didn't pay attention to calculus , derivatives , integrals in my college (finished 10 years ago) as i couldn't relate to them in real life then, they did not interest me or i didn't know the importance of it (guess many have similar stories ) , just studied to pass my exams that's it.  I don't rely on electronics for living but lately in last few years felt passionate to learn. I enjoyed working on Arduino, its probably best thing for prototyping something quick in days regardless of what other thoughts are it gives a practical education, not in theories only . I am in no rush to finish things fast , if math & physics are must to move forward my journey will be a bit slow as i expected anyways . 

My basis will be Art of Electronics & I will use references to progress and ask questions on this forum if i am stuck ( Really appreciate your responses )  . My next questions will be more specific. I am happy
1. Because its interactive ( Am not just interfacing with books and artificial intelligence " google" ) - What i wanted to
 and
2. There is no risk of me assuming something right  ( I can clarify if there are any questions ) .

I don't want to ask questions on Math as i'll research and figure them out myself , but i want to ask questions on learning tricks in practical ways.

I want to start off with my first question here, 
While working on voltage divider circuits , i was able to use bread board and experience Thevenin's theorem using resistance and load using few resistors and DMM, I was able to relate those results to the math i did and relate to .

I am studying signals now .  Theory exercises in this phase are relating to comparing signals , amplitudes , measuring them and converting to volts and power.
The only analog experiments i experimented so far are using Arduino (PWM simulator ) .  I understand Analog is more harder to experience than basics hoping not impossible. Wondering if there any way i can start doing small lab to practically do things and verify theories.

I want to be able to measure signals (with something ) , build a basic analog circuit  with (input and output ) and test linearity , scalier properties , make changes and perceive same  same in output (say led or sound similar to what i did for voltage divider & Thevenin's equivalent learning . 

Thank You in advance.

[Wimberleytech]

I want to be able to measure signals (with something ) , build a basic analog circuit  with (input and output ) and test linearity , scalier properties , make changes and perceive same  same in output (say led or sound similar to what i did for voltage divider & Thevenin's equivalent learning . 

Thank You in advance.

Do you have an oscilloscope?  If not, I suggest that you learn to use a simulator (LTSpice).  You will be able to measure voltages and currents very easily (easier than on a breadboard).

[alex_palvai]

Wimberleytech: Thanks for the quick response and reference.

[rstofer]

If you are trying to learn electronics, there is no more suitable measuring system than the Digilent Analog Discovery 2.  It has a 2 channel scope, a 2 channel arbitrary waveform generator (advanced signal generator) plus a lot of other gadgets.

https://www.eevblog.com/forum/beginners/learning-the-art-of-electronics-signal-attenuation-(figure-in-34)/

Read through the link, I make the case for the AD2 and attach some plots.

[alex_palvai]

Thank You rstofer. 

[alex_palvai]

Just finished understanding topic 1.3 (Signals ) -  Sinusoidal Sinusoidal Signals , signal amplitude and decibels topics in AoE.

I would like to contribute references i used to make my understanding clear, perhaps it will help other folks who are studying AoE .

I wanted to get a better understanding of Waves ( From physics PoV ) and i studied Chapter 8 ( Alternating currents ) from "Physics Demystified - Stab Gibilisco" book which i am using as reference . This  helped me to get a clear idea of types of waves are , Why do we need RMS , what does peak to peak mean and answered questions like why we have degrees and rad's representing same thing , similarly cycles per second and Hertz.  After getting my mind cleared on these topics i went back to AoE reread things which then became more clear ;

1.3.2 I also finished the next part "Signals and amplitude and decibels":

it took me 1 video to understand the whole topic explained on Decibels , dbm, dbu, dbV (what they all are and how they are originated. ) .  The way this guy explained the topic is an Epic of explanations.



Hope it helps.

[Wimberleytech]

Decibels
This is from my files.  It is from an article retyped by my secretary (back when you called them that) back in 1985.  I seem to recall some typos somewhere but am not checking it here before posting.

[rstofer]

The way this guy explained the topic is an Epic of explanations.

Alan Wolke, w2aew, has a bunch of very good videos.  It is worth the time to peruse his site.  Dave also has some excellent videos in his Fundamentals Fridays series.  Dave's Op Amp video remains a personal favorite.  EEV Blog #600 - What Is An Op Amp?

FWIW, there is a very long Oscilloscope tutorial linked at the top of this forum.  It, too, is Alan's work.  He is an application  engineer at Tektronix so that's why he has all the cool test equipment.  It's interesting to see him use old Simpson 260 V-O-Ms instead of DMMs for some of his videos.

[rstofer]

As explained in the video above, when comparing voltage (say the input and output voltages of a low pass filter), the form is

dBV = 20 log (Vout/Vin)

That -3dBV breakpoint in the Bode' Plot has an Vout/Vin ratio calculated as

-3dBV = 20 log (Vout/Vin).  Divide through by 20 and you get -3/20 = log (Vout/Vin).  Then take the antilog of both sides

10^(-3/20) = Vout/Vin  which results in 0.707 = Vout/Vin  If Vin is 1V then Vout at the -3dBV point is 0.707V, less than the input voltage, as expected.