Need advice regarding learning electronics circuit analyse/design at home

• Need advice regarding learning electronics circuit analyse/design at home
  Posted by stoica adrian on 28 Oct, 2019 12:32
• Hi,
  
  I just finished reading the Learning of Art of Electronics, page by page, and i have done all the labs from the book.
  Drawing a line now, i feel like i cheat myself because i read the book like an ordinary magazine, and i don't remember too much from the book. Except that i know where to look in case if i need some information.
  Do you think that is best to take page by page, while learning electronics (AoE or another book) and spend some time on each circuit to analyse in depth, or reading in a first go is the best idea.
  What do you think?
  
  Thanks
  
• #1 Reply
  Posted by capt bullshot on 28 Oct, 2019 12:48
• Best (and maybe only) way to learn circuit design is to design real circuits.
  Best (and maybe only) way to learn to analyze circuits is to analyze real circuits.
  
  Having read some stuff is helpful, indeed. Usually you want to know where to look up something special when you run into some issue when doing the real thing.
  
• #2 Reply
  Posted by Jar-N2 on 28 Oct, 2019 12:53
• Agreed. Getting your hands dirty is the best way to learn. Simulators and breadboards, trial and error.
• #3 Reply
  Posted by rstofer on 28 Oct, 2019 15:56
• First, we need to decide if this is a hobby or an attempt at a career change.  If you plan to do EE as a career, strap in for a 5 years of education and the AoE isn't nearly sufficient.
  
  For a hobby, reading a book isn't particularly useful other than to learn where in the book certain concepts are discussed.  The only way to learn the material is through practice.  Design something and analyze the heck out of it.  Design the circuit, simulate the circuit with LTspice and then build/measure the circuit on a breadboard.  Keep lots of notes.  You can use the lab experiments from the book.  Don't count on getting the same answer.  Two reasons, tolerances and the possibility that the book is wrong.  Believe what you measure, not what you read.
  
  Take the simple battery/resistor networks, analyze them with Kirchhoff's Laws, simulate them and measure the results with LTspice and then build the network and measure everything.  The answers won't agree due to tolerances but you should be close enough.  I posted the wxMaxima solution to KVL and KCL for a specific resistor question but you can rip the code and use it for all of your work
  
  https://www.eevblog.com/forum/beginners/kvl-and-kcl-equations/
  
  All of this can be done with a simple DMM.  What test equipment do you have access to?  You won't go far in the time domain without a scope or in the frequency domain without a way to create Bode' Plots or FFTs.
  
  Next up would be RC networks in both the time and frequency domains.  You want to truly understand the charge and discharge equations for an RC circuit in the time domain and you also need to understand how they work as a filter in the frequency domain.  This is where things start to get interesting.  Resistor networks are boring...
  
  Progress through RLC circuits, again in both time and frequency domains.
  
  Now you can start playing with things like the common emitter amplifier and the CE amplifier with emitter degeneration (see W2AEW's video on transistor amplifiers).  Get the transistor datasheet, be overwhelmed by all the numbers, each of which limits how you can use the device, and see what values you actually get on the breadboard.
  
  
  
  Then learn how to use the transistor as a simple switch to light an LED, for example, from a uC output pin.  Learn how to calculate the LED resistor from Kirchhoff's Laws.  Learn how to calculate the base resistor from the collector current and hFE.
  
  At this point, you're at about the end of the first year of EE.  Maybe not quite...  From here on, things get a little more involved.
  
  Try the Khan Academy Electrical Engineering videos and Digilent's True Real Analog lectures.  At this point, the math is going to get intense.
  
  I asked above about what test equipment you had access to.  If the answer is "none", you might be in luck.
  
  If I were starting from scratch, knowing what I know now, 50 years after starting college, I would buy the Analog Discovery 2.  I know, a lot of people scoff at this but they're making a big mistake.  For $279, you get a decent dual channel scope and a dual channel Arbitrary Waveform Generator along with a dual power supply and 16 bits of bidirectional digital ports.  Before you blow it off, download the Waveforms software and play with the Demo device.  This is the most amazing educational tool in the world.  It doesn't have the knobs and dials of a bench full of equipment but it is targeted specifically at students.  It is also useful for really old guys who have a pretty full bench of equipment.
  
  You can do a Bode' Plot of a filter using the built-in AWG to provide the input signal and the scope channels to display the phase and frequency response.  This is amazingly hard to do with a bench scope and signal generator.  If you want the FFT of a signal, say a square wave, the AD2 will provide the waveform and perform the entire analysis.  This capability exists, to some extent, on modern DSOs.
  
  Run the Spectrum gadget in demo mode, select a start frequency of 0 Hz and an end frequency of 10 kHz and you will see the FFT for some magical 1 kHz square wave.  Play with all of the gadgets and see what you think.
  
  Did I mention that once you get past the RC and RLC circuits, the math gets more involved?  Frankly, the equations for RLC circuits are pretty complex but they are well understood so it's not often that students really need Differential Equations to solve them.  Get real familiar with wxMaxima.  I also highly recommend MATLAB and the Personal license isn't terribly expensive but it isn't free.  Octave is a perfectly good substitute and it's free.
  
  Just build stuff!  Have fun!
  
• #4 Reply
  Posted by rstofer on 28 Oct, 2019 16:08
• Quote from: stoica adrian on 28 Oct, 2019 13:29

  Hi,
  
  Thanks for your advice. One question though, in Art of Electronics there are a lot of design exercise, i can try to do all of the design, but now i fear that i will reach microcontrollers or other topic from the end of the book in one or two years. I don't know how much time should i dedicate to analyse a chapter/subchaper/page/design.
  What are your suggestions?
  
  
  Thanks,
  

  
  I gave the LONG answer above.  Now the SHORT answer!  What do you want to do?  Yup!  That's the answer - do what you want to do.
  
  You don't need much design experience to use an Arduino and a pre-manufactured Shield.  Everything that can possibly be done with an Arduino has already been done and the projects are on the Internet.  There's nothing wrong with finding one and duplicating it.  Then use your analytical skills to figure out WHY it works.  Figure things out!
  
  As a hobby, electronics is supposed to be fun!  EE school is NOT fun!  It is 5 years of no sleep, vast quantities of caffeine and math spilling out all over the place.  And not a practical project to be seen!
  
  Find something interesting and build it.  Then think about how you could make it better.
  
  Make a list of what you want to do and post again.  Somebody will get you on the path toward YOUR goals.
  
• #5 Reply
  Posted by rstofer on 28 Oct, 2019 18:40
• If you want to do design problems from AoE or lab experiments from LTAoE, pick the ones that interest you.  You don't have to do every single problem and experiment in the books.  LTAoE -> Learning the Art of Electronics (the lab manual for AoE).
  
  The digital experiments in LTAoE may be obsolete.  Nobody is using discrete logic chips, it's all being done with FPGAs and I don't think that is included in the book.  Maybe back in the '80s (or earlier) chips were used for logic but not any longer.
  
  More emphasis should be placed on uCs and interfacing.  Over the last 10 years there has been a large shift from designing hardware to writing firmware.  uC chips are all over the place and they can do some amazing things, given appropriate firmware.  Our expectations have changed, we expect a graphic UI on everything.  Touch-screen rates a bonus.
  
  Bottom line:  Do a few of the more interesting problems and experiments and move on.  If you want to get to uCs, start with uCs, writing code, probably for an Arduino, and work backwards.
  
  Everybody laughs at Arduino programmers but here's the thing:  You don't have to use the Arduino libraries to use the platform.  Underlying all the libraries is avr-libc and the avr-gcc (the compiler tools).  Very few people write code this way but it eliminates all of the bloat in Arduino projects and gives you direct access to the hardware.  Yes, it's a lot more work.  Whether it is worth it depends on what you want to do.
  
  https://www.microchip.com/mplab/avr-support/avr-and-arm-toolchains-c-compilers
  
  You don't need any of these tools because, at least for the ATmega chips, they are already installed with the Arduino IDE.
  
  Then move on to the more modern ARM chips.  Any of the STM boards, particularly those that are mbed compatible (mbed.org) and now you're up to date.