While it is a hobby, I do want to get serious with it and have the ability to do complex things and actually know what I'm doing (at least to some degree). I am currently planning to go deeper into Calculus very soon, but I just want a general electronics resource where I can obtain the knowledge to make almost anything (or at least, the fundamentals to move on to a learning source where I can obtain the knowledge to make almost everything). From what I've seen, there are good learning sources that don't require calculus, although it is a nice-to-have. So, I do want to approach it as an academic exercise with a hobby aspect, I guess, at least for now, since I'm mainly interested in acquiring skills. What would be your opinion on the resources I mentioned?
Electronics is a VAST topic and people spend an entire career working in one small corner of the sandbox.
Were it me, I would try some of the kits available at Amazon just to get the flavor of working with components. In the background, I would be going through the programs at CalcWorkshop and KhanAcademy. I would learn the fundamentals of DC circuits by studying Ohm's Law, Thevenin and Norton equivalent circuits, Kirchhoff's Laws (as a side issue, I would learn how to solve matrix problems with Octave or MATLAB), nodal and mesh analysis and perhaps basic transistor circuits for switching. I would leave amplifiers until I had time to go through a program in AC circuits. They're a lot like DC circuits but they bring in complex numbers. At this point, I would be looking to upgrade my lab.
A little nodal analysis just for giggles (start at Reply 5 for the answers). With nodal analysis, we treat the common trace above the resistors as a single node and assume current flows for the 3 resistor branches and ignore the op amp input because it doesn't draw current (ideal op amp rule). All of the currents are assumed to be leaving the node but the sum must equal zero. Clearly, one of more branches are going to have negative current because we assumed the wrong direction. No worries, it all works out when you add them up, they will come to 0.
https://www.eevblog.com/forum/projects/is-this-possible-301664/The current in each branch is determined from Ohm's Law as (Vnode - Vsource) / R which can have any value but 1 Ohm works for calculating the voltage. It doesn't work well for the op amp feedback so I picked 1k later on (read further for the complete solution). Install LTspice and download the models.
Here's a little MATLAB code to study a time delay capacitor/resistor circuit - start at Reply 6 See CarRC.pdf (attahced)
https://www.eevblog.com/forum/beginners/how-to-delay-a-relay-opening/msg3849953/#msg3849953I like it when we get to do math problems on eevBlog!
You need at least a dual channel scope, a dual channel arbitrary waveform generator and a lot of the other toys that come along with the Digilent Analog Discovery 2. It was a lot easier to recommend this at the old price of $279. At $400, it's a hard sell except: It has a dual channel scope, a dual channel arbitrary waveform generator, 16 bits of digital IO which can be used as a logic analyzer, a dual channel DMM and other gadgets like the network analyzer (you will find this useful when you get to filters and Bode' Plots. Read up on it, I find it my most used piece of test equipment.
https://digilent.com/shop/analog-discovery-2-100ms-s-usb-oscilloscope-logic-analyzer-and-variable-power-supply/Install the Waveforms software and poke around with the 'Demo' device just to get a flavor of what the machine can do. I can spend an entire day with the AD2, a 10k resistor and a 0.1 ufd ceramic capacitor. I can look at the forced response by hitting the RC circuit with a square wave or I can look at the frequency domain by sweeping across the frequency spectrum looking at attenuation. This gadget really is useful and many universities are now using them instead of a bench full of test equipment. Everything a student needs and it fits in the side pocket of a backpack. I have attached 3 of the screen shots.
https://digilent.com/shop/software/digilent-waveforms/The BodePlot.png file shows the frequency response of a low pass filter using my favorite 10k resistor and 0.1 ufd capacitor. We're interested in where the top trace is -3dB down. We used to just handwave this stuff in college back in the day but now it's trivial to get an actual answer.
The ForcedResponse.png shows the response from the same low pass filter getting hit with an 83 Hz square wave. I wanted to show the charge and discharge curves for several time constants. You will learn that Vout = Vin * (1-e
-t/Tau) and Tau is the time constant equal to R(Ohms) times C(Farads). Since Tau = 1 ms, we are watching a 6*Tau charge and a 6*Tau discharge. You will learn that at 6 Tau, the capacitor is 99.75% charged or discharged.
Finally, there is a Fast Fourier Transform of a 1 MHz square wave. The spikes show the voltage in the harmonics. You will learn that a square wave can be composed of sine waves starting with the fundamental frequency and adding in all the odd harmonics at declining amplitudes out to infinity (which we can't really reach). In any event, we might only be interested in a few harmonics. This comes up when you buy a 100 MHz clock and find that after about 10 MHz, square waves start to look increasing like just a sine wave. At 100 MHz, it will usually look exactly like a sine wave because the 3rd harmonic (the next after the fundamental) is 300 MHz and the scope can't display much at that frequency. Keep that in mind...
I really like the tool and I figure it is the best way for students to go. They have all the tools they will need in a small box, easy to transport. I understand that most people are going to blow it off and buy discrete tools because, individually, they will have better specs but if they duplicate everything in the AD2, they're going to have a bunch of money in test equipment. Everybody gets to make their own choice!
I like playing around with circuits from time to time. When I do, it is almost always with the AD2 even though I have a bench full of test equipment.