The intuitive mind is a sacred gift and the rational mind is a faithful servant.

We have created a society that honors the servant and has forgotten the gift.

Albert Einstein


An interesting discussion about the biasing idea of a common-emitter amplifier at the whiteboard in the lecture hall (the photo is made by Lora Kirilova on April 23, 2008).

Teaching philosophy

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My name is Cyril Mechkov. I have been teaching basic, analog, digital and mixed electronics since 1986 at the Computer Systems Department of Technical University of Sofia. My teaching philosophy (see my EWME paper to know more about it) is simple:

1. Electronic circuits are based on clear and simple basic ideas, which may be derived from our routine.

2. To really understand electronic circuits, we - human beings, first have to reveal these basic ideas.

3. To successfully present circuits to students, we teachers have to build them step-by-step according to the basic ideas revealed.

4. To make students create new circuits, we teachers have to (re)invent the existing circuits according to the basic ideas behind them.

I just believe that we - human beings - can really understand abstract electronic circuits relying only on our human intuition, imagination and common sense. Basic circuit ideas are "non-electrical"; they do not depend on the specific implementation (tube, transistor, op-amp etc.) They are immortal; they are eternal!

My Wikipedia mission

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I joined electronics Wikipedia in 2006 with great enthusiasm. I was noted that Wikipedia articles in this area were formal and theoretic; there had not introductory sections saying what the circuit idea actually was. Thus I came with clear and obvious purpose - to reveal the basic ideas behind circuits by clear and obvious explanations based only on basic electricity and electronics laws, human intuition and common sense.

My motives

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I have a natural interest in generalizations and parallels in circuitry. My pursuit is to reveal the fundamental ideas behind circuits - to show not only what circuits do but how and why they do it. Long ago, I noted that inventors, scientific researchers and producers do not like to disclose the secrets behind circuits as they want to benefit from them. They have no time to explain them to people; they do not see any reason to do it for people; they have to earn money (for themselves or for their employers). I have refused to benefit something from my insights about circuits; I am not obliged to generate them for someone; I am free to share them with people... I do not bury them in some pay sections, articles or books where they will die. I do (did) it in Wikipedia because of its highest Google rank. Thus, if a month ago some curious young visitor typed "negative resistance" in the Google window and then clicked on the first Google suggestion, he/she would learn what differential and true negative resistors are, what the difference between them is, how to make them, etc. But if the curious visitor does the same now, he/she will learn nothing from the current miserable version and maybe he/she will never visit this page again. This is (was) my idea of Wikipedia contributing.

My way of thinking

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In the op-amp circuit of a transimpedance amplifier (perfect current-to-voltage converter or "ideal" ammeter), the op-amp compensates the undesired voltage drop VR = IINR across the resistor R by adding equivalent voltage VOUT = -IINR.

As a rule, my edits are considered by orthodox wikipedians as an original research. The "problem" is that my mind is arranged in such a way that I always manage to see, extract, generalize and explain easily basic circuit ideas. This affords an opportunity to me of reducing the complex circuit solutions to extremely simple and comprehensible equivalent electrical circuits that do not need citing. Maybe, this is a unique mental ability since I cannot find sources revealing circuit ideas in such a way; thus the problem with citing.

All the written by me in Wikipedia articles is the very simple, obvious and clear truth about circuits. It can be immediately seen if only look at the written; it can be immediately verified only by means of common sense. It is a truth that can be explained to and will be realized by every ordinary human being. It can be explained (of course by using appropriate analogies, metaphors and relations) even to a curious 6-year boy (Einstein)! This is the power of my intuitive, qualitative explanations; this is the reason to not cite them...

My great circuit insight

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I will illustrate this my mental ability by revealing the basic idea behind the legendary transimpedance amplifier (in the talk pages of Miller theorem and Voltage compensation, I have emotionally told how I realized this extremely simple but great voltage compensation idea in the early 90's). Then I saw that in this circuit, the op-amp acts as a compensating voltage source adding so much voltage VOUT = -IINR as it loses across the resistor. In this way, it neutralizes the undesired voltage drop VR across the resistor; a virtual ground appears at the op-amp inverting input and the resistance R is eliminated. Thus I reduced this electronic circuit to a more elementary electrical circuit consisting only of a resistor R and a voltage source VOUT connected in series.

Then, I noted that this simple but powerful idea (connecting an equivalent voltage source in series to a passive element to compensate the voltage drop across it) is developed further in circuits with true negative impedance (VNIC) where the "inserted" voltage exceeds the voltage drop across the element. Finally, I generalized it in Miller theorem but it is even more general; it is non-electrical. So, we can see it everywhere around us as the universal principle of compensating energy losses with equivalent additional energy.

Wikipedia contributions

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Since 2006, I have made 7200 edits in main and talk pages. Most of them are removed and thrown away in history. I have extracted and placed a list of links to all these resources (both present and old) below to give a chance to readers to learn about the basic ideas behind these circuits.

Miller theorem

Miller theorem was created and maintained completely by me. The theorem and its dual are shown not only as effective tools for creating equivalent circuits but also as powerful tools for designing and understanding circuits based on modifying impedance by additional voltage or current.
Talk:Miller theorem begins with an exciting story about realizing and developing my notion about the great idea. Then I have shown the key points of exposing Miller theorem.
Op-amp applications of Miller theorem shows some my thoughts about Miller theorem.
How to modify impedance is my first attempt to enlarge and generalize the Miller effect (I have based Miller theorem on these my insights).

Negative resistance

Negative resistance (my last version, about 80% share). I have been developing this page since 2006. I have shown what differential and true negative resistance are and how differential and true negative resistors (circuits) can be implemented. In contrast to previous my versions, I have considered the behavior of negative resistors in the three regions of their "S" or "N" shaped IV curves (positive - negative - positive). I have finally generalized negative resistance into negative impedance.
Negative resistance old (February 6, 2009) is an improved and very well developed story about the truth behind negative resistance. Only the negative resistance regions of IV curves are considered.
Negative resistance very old (December 3, 2006) is my first naive but enthusiastic version of this page. Then I had no notion about wikipedian manners and customs.
Another fresh viewpoint at negative resistance (September, 2006) is my first insertion to Negative resistance talk page; it is a suggestion for reconstructing the main article.
What negative impedance is is an old discussion where I have explained that there is and what is negative impedance.
Talk:Revealing the truth about Deborah Chung's "apparent negative resistance" is a copy of an old Wikipedia discussion (already deleted) where I have revealed the truth about Chung's experiment as a great misconception in the area of negative resistance phenomena.
Howland circuit is my reply where I have revealed the secret of the legendary Howland current source (I have shown that it is a negative resistance circuit).
Negative resistance amplifier contains interesting thoughts about using a negative resistor as an amplifier.
Positive feedback -> negative resistance? are interesting thoughts about the nature of differential resistance.
How do op-amp negative impedance circuits (INIC) work? is a list of questions about the nature and implementation of negative impedance converters.
What is the basic idea behind a negative impedance converter (NIC)? (July 1, 2006) is my first material about the fundamental ideas behind NICs.
Why the neon lamp is a negative resistor and how it behaves when voltage driven

Virtual ground

Current-to-voltage converter shows step-by-step the evolution of the imperfect passive circuit (a humble resistor) to the almost ideal op-amp version by compensating the undesired voltage drop across the resistor.
Voltage-to-current converter is a dual story (created and maintained completely by me) showing how the imperfect passive circuit (again a humble resistor) can be made act as almost ideal one by compensating the undesired voltage drop across the load.
Virtual ground (December 14, 2007)
Talk:Virtual Ground is an extract from an old Wikipedia discussion about the virtual ground phenomenon

Oscillators

Relaxation versus LC oscillations is a comparison between the two kinds of oscillators.
How do RC oscillators produce sine wave? is this last unhappy discussion where I have done all my best to reveal the truth about RC oscillators and particularly, Wien bridge oscillator.
Negative resistance LC oscillator is a similar discussion about the powerful negative resistance viewpoint at electronic oscillators.
Electrical resonance is an intuitive explanation of the ubiquitous phenomenon based on the negative impedance viewpoint.
Multivibrator. Here I have explained in details the operation of the astable multivibrator.
Revealing the truth about electrical resonance phenomenon is my great insight about the ubiquitous phenomenon.
How are hysteresis and positive feedback related?
The operation should be illustrated by the AC load line

Digital circuits

Diode logic is dedicated to the first logic family. In the introductory part of the article, I have revealed the secret of the odd diode AND logic gate (the diode AND gate is actually a diode OR gate with inverted inputs and output).
Resistor–transistor logic is my first insight about the fundamental idea behind logical operation OR: it is performed by applying consecutively the two arithmetic operations addition and comparison (particularly in RTL, the input resistor network acts as a parallel voltage summer with equally weighted inputs and the next common-emitter transistor stage - as a voltage comparator with a threshold about 0.7 V).
Transistor–transistor logic. In the introductory part of the article, I have revealed the truth about TTL by using the fundamental concept of current steering. I have shown that TTL has come from DTL since the base-emitter junctions of the input multiple-emitter transistor act exactly as the diode switches of DTL (this fundamental idea is removed from the current version).
Emitter-coupled logic page is my great achievement in the area of basic logic gates. I have managed to force my great insight (presenting ECL as a transistor stage with switchable emitter voltage and current sources) upon wikipedians inhabiting this space and even to place a link to the impressive ECL wikibooks story. In the beginning of September 2011, I presented two papers dedicated to basic ideas and the operation of ECL at CS conference in Ohrid.
Schmitt trigger (about 80% share). Here I have revealed in details the basic idea and the operation of the legendary circuit (transistor and op-amp version).
Flip-flop. In the introductory part of this article I have shown how the elementary memory cell (latch) is built.

Amplifiers

Differential amplifier reveals the secrets behind the operation of the long-tailed pair.
Operational amplifier. In the section about the op-amp internal structure, I have revealed the secrets of Widlar op-amp input differential stage.
Demystifying negative feedback contains my insights about the unique properties of negative feedback amplifiers.

Electronic elements (real and simulated)

Why there is a phase shift between the current and voltage in a capacitor is an intuitive explanation of the lag phenomenon of capacitors in the talk page (based on a correspondence between me and a curious web reader).
What memristors, memcapacitors and meminductors are reveals the secret of memristive elements in the talk page (in contrast to the introductory article part, it shows that there is nothing magnetic in a memristor).
Gyrator presents this odd circuit as a bridge.
Demystifying gyrator circuits is one of my great circuit insights revealing the secret of gyrator (а simulated inductor).
Current source

(to be continued...)

Wikibooks contributions

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I have established Circuit idea to show how to reveal the ideas behind circuits. The main purpose of this e-book is to reveal once and for all the true, pure and real fundamental ideas behind circuits. It establishes new human-friendly circuit philosophy as an alternative to the classical formal "robot-friendly" approach:) This philosophy relies more on human imagination than on logical reasoning. It considers analog circuitry more as art than science and the creation of electronic circuits as a result of human fantasy, imagination and enthusiasm. If you have an interesting story about amazing circuit phenomenon, contribute to the novel book!

Joining students to Circuit idea

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In the beginning of March, 2008 I decided to join my students to Circuit idea. I started this initiative "in sport" but it turned out so successful and exciting that now I am entirely absorbed in this new web undertaking. I have told how it has started in the discussion of the first completely finished page that my students and I have dedicated to the famous Ohm's experiment.

You can imagine how powerful this wiki approach is where students and their teacher, all together, work on the same common project! They add, edit and continuously refine it; they learn how to present what they have done to other, how to contribute a wiki project, how to communicate with people, etc. Furthermore, any web visitors (including other students and their teachers) through the world can join and enrich this open project! If you are a teacher, student or you just like education, join our web initiative! Here are links to my student groups:

Group 64aGroup 65aGroup 66aGroup 67aGroup 68aGroup 64bGroup 65bGroup 66bGroup 67bGroup 68b

Resources

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If you would like to know more about me, visit my informal bio, my philosophy and all the materials located at my site circuit-fantasia.com.