In the world of simulations
The prerequisites
For a very long time, years, I have refrained from working with programs for simulating electrical and electronic circuits. I thought they would get in the way of my creative thinking. I have preferred to imagine for myself, with the power of my imagination, intuition and practical sense gained through real experiments and practice, the operation of circuits. I have often joked that "my brain is my simulator" :-)
My concerns have been that simulators are heavy and clunky, often wrong, and require a lot of expertise to get them to correctly represent the operation of the circuits. So, I thought, I can never be sure of what they show.
I have generally thought that simulations are for formal, logical-minded people who are more mathematicians than technicians. I do not know if it was just me or it is generally like that, but I have always been surrounded by such people - smart, knowledgeable... but not understanding. For them, circuits are something existing, as if given to us by God, which only needs to be analyzed through complex mathematical expressions and passed on to students (my observations are from the institution where I studied and then worked). My colleagues used the simulations mostly to give a (pseudo)scientific appearance to their publications, not so much to reveal the secrets of circuits.
How I explored circuits
However, I am a technician and inventor by birth and a teacher by profession (see my creative bio). I visualize the operation of electrical and electronic circuits with my imagination rather than my mind, visualizing the invisible electrical quantities (voltage, current and resistance) on the mental inner "screen" of my imagination. To me, electronic components (diodes, transistors and op-amps) are like living beings. To understand them, I mentally put myself in their place and imagine how they act. When I need to check if it is as I imagined it, I do simple real-world experiments with "tricky" devices and trial setups in the lab. That was until last year...
The change
... but there was a change... I no longer had a laboratory in which to do real experiments, and I could not afford to make a "home laboratory" like I used to have as a hobbyist. It is just that now it was no longer possible to buy appliances and all kinds of elements, to run to the store if I was doing an experiment and at the moment I wanted to change something. And my goal is not to make devices to keep and use... but to experiment with circuits to understand them and tell them on the web.
CircuitLab
At the beginning of this year, somewhat impulsively and as a joke, I started using the *CircuitLab* simulator... and I was fascinated - first by its graphical editor, and then by the very simulator. Again I had a "lab" - really not quite real but "simulation"... and it was still a laboratory...
The main advantage of this substitution of the real for the simulated is that experiments become very easy. The elements are large, simplified, easy and intuitive to move, rotate, jump with each other; the diagrams are cleared of details, I stack them like Lego blocks and I am happy like a little child. I do not need very specific and varied elements; I need "conceptual" elements that I can change the properties of. For example, I need a diode with a certain threshold voltage - I do it with an "ideal diode" from the CircuitLab library, to which I set the forward voltage drop in the "parameters" panel. This is actually not just a diode, but a voltage stabilizer.
My circuits are conceptual, so the simulator fits them very well. These are "ideal" experiments; they do not end with making a board and a device. The goal here is not to use the device, but to understand the idea and explain it to others. I have worked a bit with some programs like CADSTAR that allow to get to a circuit board. The most complex board I have made with it was an analog I/O controller for a PC. What I dislike about these programs are the detailed circuit diagrams. And to be honest, I really hated making boards. This has not given me pleasure, except in my school years, when I made simple printed circuit boards in a primitive way (painting them with asphalt varnish, etching them with iron trichloride). Later at university there were people around me, colleagues, who found this (and not revealing the circuit ideas) supreme pleasure. I explain it by the fact that I am not a designer, I am not a person who creates devices with the idea of profiting from them. Ideas and philosophy are valuable to me. I am into "ideal" stuff and that is why this simulator suited me so well.
Up until now, I have been making a lot of use of my old resources with lush, hand-drawn color illustrations by posting links to them. But gradually I began to give them up, no matter how good they were. Now I do it with the CircuitLab editor, visualizing the currents sparingly with small, unobtrusive arrows. I have not figured out how to visualize the voltages yet (maybe it will still be with arrows, but in red).
One of the great advantages of this way of working is that I get support, confirmation from CircuitLab that my ideas are right, and readers trust me. It is difficult to dispute the numerical and graphical results obtained after the simulations.
With this tool, I can arrange my schematics very well. Best of all, I can do step-by-step "scenarios". They are made very easily, "back to front" - I start with the last, most complex scheme, and gradually remove the elements from it; thus I arrive at the first, simplest schematic. Now I feel the greatest pleasure when I sit down to make another such scenario, assemble schematics and experiment. I have not experienced this in a long time, to say never. With real circuits, it becomes difficult and your desire fades gradually.
I think the simulator actually does it in the same artificial way that I do the equivalent circuits (man-controlled) of the electronic elements by replacing them with equations. But it happens that sometimes I, like other people, forget about it and start thinking that it is a real circuit. But I have experience and it allows me to work for a long time without touching anything. So I am actually exploiting my practical psychomotor models that I have accumulated from life to be able to continue now with simulation models. Here, this is a very significant difference between me and the "newbies" without practical experience, who only simulate and have not made a real circuit before. It is common knowledge that it is impossible with only simulations until you master the circuits. The right way is first real and then simulation... as it is in life... For example, how does a writer write a book? He does not make real situations, but uses his life experience to see them in his mind and recreate them in writing.
CircuitLab tricks
Because I am an "inventor at heart", I immediately started inventing various clever tricks, which are much easier with the simulator than in reality.
Tuning values
Adjusting values by "feedback", that is, by looking at an indicator, is my idea, which I immediately started to implement. That way, I do not need to calculate, I just "add" the value. Or, as I often like to say, "CircuitLab freed me from the yoke of equations".
Deliberately degraded meters
Normally an "ideal" ammeter has zero resistance, and an "ideal" voltmeter infinitely large. A very clever trick, however, is to deliberately give them some resistance. In this way, not only can we see the effect of their internal resistance on the measurements, but we can also use them as "resistors". This is how we simplify schematics.
... and many others explained in My CircuitLab bag of tricks.
Links to CircuitLab stories
Here are links to my strongest CircuitLab stories, where you can see how I put these ideas into practice:
How does a transistor inverter work? is my first CircuitLab story laid out in four consecutive steps (frames). There are no graphs of the simulations (the topic does not require it).
How does this rectifier work, since the op-amp input is 0 V? is my first full CircuitLab story, laid out in five "frames". In addition to schematics, I have richly illustrated it with graphs from the simulations.
Why do we need R1 in a non-inverting op-amp? is a lush story, in which I first applied schematic framing (to unify scale).
Puzzled with parallel forward biased diodes with common anode and different cathode voltages is a long story in which I reveal the philosophy of output stages.
Non-inverting op-amp is a very long and richly illustrated story, in which I reveal the philosophy of the non-inverting and inverting amplifier.
Help me calculate voltage drops through this circuit is a CircuitLab story in which I reveal the ideas behind a common emitter transistor amplifier stage in three ways - by understanding, building and "inventing".
I have to find the relationship between Vout and Vin is a story dedicated to the follower, non-inverting amplifier and differential amplifier made using an operational amplifier.
Maximum voltage range for input in emitter follower is another amazing story dedicated to the output stages of electronic amplifiers.
Voltage divider equation tunnel diode - Art of Electronics reveals the mystical phenomenon behind the differential negative resistance of tunel diodes.
Powering a negative resistance converter with an Arduino power pin reveals the idea of the mystical "negative resistance converter".
How does negative feedback stabilize the output of an op-amp? is a unique inverting amplifier story in which I invent a new tool to "see" the voltage inside resistors.
How does an inverting op-amp feed back 0 V when Vout is not 0? is another unique story where I reveal the philosophy behind negative feedback op amps using an invented "tool".
Usage of input voltages in ideal opampis is another story devoted to the philosophy of negative feedback op amps.
How does this op-amp config work as a voltage follower? is a detailed story dedicated specifically to the voltage repeater.
How does one set the Q-point for a JFET cascode amplifier, and what are the correct "Idss" requirements for cascoded JFETs? is an amazing story about mystical cascode circuits.
Resistors values for class AB amplifieris a huge story devoted to counter-clockwise power stages in amplifiers.
Single-supply non-inverting op-amp for summing DC voltages at unity gain is a very detailed history of both types of summer s - non-inverting and inverting.
TTL NAND gate analysis is a different story than the previous ones because it is dedicated to the most basic NAND logic circuit.
Why is the voltage drop across the collector emitter junction of common emitter configuration the output voltage instead of that of load resistance? is an amazing story about the elementary transistor amplifier stage that I dedicated to jonk.
Series RLC - how does resonance amplify?is a story about how resonance "amplifies".
If multiple sources are parallel with the diode, why does the one with a higher voltage turn on? is devoted to diode switching circuits.
Comparator with hysteresis; what resistors go where? is a very extensive story of INIC negative resistance circuits.
Class AB crossover distortion diode fix is a comprehensive story with many illustrations devoted to diode bias circuits in flyback stages.
Clipper circuit in OpAmp takes a very detailed, step-by-step look at diode limiters.
Inverting op-amp problem examines in detail an unconventional amplifier using a common-mode input voltage.
Understanding biasing typologies of a class AB amplifier is devoted to the input biasing circuits of "push-pull" amplifier stages.
What is the basic idea behind the so-called "diamond buffer"? is a question given by me and accompanied by my answer.
Controlling one relay with three LEDs - energize relay if any one of the three LEDs are lit is a bit of an inventive solution.
"Source", "sink" or both? is another question asked by me and accompanied by my answer.
Do voltage multiplier circuits and transformerless power supplies have functional similarity? is an amazing story about transformerless voltage multipliers.
Diode connected BJT instead of a diode is a continuation of an old answer of mine in which I have added CircuitLab simulations.
How can I control PNP and NPN transistors together from one pin? is an invention story dedicated to the so-called "diamond buffer".
Diode-connected BJT vs base-emitter BJT diode vs diode is one of my strongest stories dedicated to the so-called "active diode" and the "current mirror".
Equivalence between diode and transistor is another very strong story dedicated to the "active diode".
Calculating resistance of a load inspired me to show how we can understand diodes and other nonlinear elements.
How does a current mirror work? is an amazing story dedicated specifically to the "current mirror".
How to toggle relay with single push-button is again a story of invention in which I managed to do the impossible - to alternatively command a relay by means of a button (electromechanical T trigger).
Do I need a pulldown resistor with a voltage follower? is an interesting story in which I reveal the peculiarities of the emitter follower.
Use LEDs to indicate voltage is another invention story where I show how to make an LED "ladder" powered by the input voltage.
Tie an input of an AND gate to its output is a story revealing the philosophy of the most basic RS latch.
What's the point of Vcc and Vee closed loop in op amp inverter reveals the truth about the so-called "coupling" and "decoupling" ("bypass") capacitors.
Output voltage level of TTL gate considers the output part of TTL logic gates by building the stage.
What is the role of the capacitor in clamper circuit? shows the connection between seemengly different diode circuits - a clamper and half-wave rectifier.
Does changing the collector resistance of a common base amplifier have any effect on the current? is a comprehensive CircuitLab story about the common-base amplifier stage where I have built the circuit step-by-step.
Why does a common base amplifier give a non inverting output? presents the common-emitter and common base amplifier stage in an unconventional way - through the Wheatstone bridge circuit.
How does current affect voltage? is a story about the ubiquitous potentiometer.
Small circuit explanation is about a simple passive circuit containing resistors, capacitors and diodes.
Circuit analysis of op amp non-inverting integrator reveals the idea behind an exotic circuit solution of a non-inverting integrator.
Why does the current not divert in the inverting summing amplifier circuit? shows the basic ideas behind voltage summers.
Transistor functionality confusion creates a functional notion about the "transistor in a simple way through equivalent electrical devices. I have done it in six steps by building a conceptual transistor amplifier.
Transistor switching is a CircuitLab story about the transistor modes of operation
Flyback diode for a relay in a car explains how the flyback diode reduces the back emf voltage of a coil.
Control two LEDs with only one PIC output is a little invention of mine which is a minimalistic LED indicator circuit.
Is there a circuit to detect if a line is high-impedance? is another invention of mine which is a minimalistic LED indicator circuit.
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