65 Questions 1K Answers 0 Followers
Questions related from Cyril Mechkov
I have been thinking for a long time on the so-called "Early voltage". What interests me is whether there can be some physical explanation of this quite artificial definition. IMO this concept...
02 February 2018 3,184 16 View
I have not met a simpler circuit of a curve tracer than the shown below (a transformer, resistor and of course, the diode under test). Although it is a simple passive circuit, I claim it is...
11 November 2017 6,321 0 View
We have seen a balanced bridge circuit in the basic circuit of...
09 September 2016 8,863 34 View
The load line is widely used in the graphical analysis of transistor circuits... https://en.wikipedia.org/wiki/Load_line_(electronics) ... but, as a rule, it is presented in a formal way... just...
05 May 2016 1,309 90 View
Once clarified what "load line" exactly means... https://www.researchgate.net/post/What_is_actually_a_load_line_and_can_this_concept_be_presented_in_a_more_attractive_way_to_students ...now it...
05 May 2016 6,923 8 View
It was very interesting to me to discuss how to investigate circuit elements (e.g., semiconductor devices) in the simplest, elegant and clever...
03 March 2016 4,581 80 View
As already I shared with you, my students and I managed to unravel many of the mysteries of the mere potentiometer in the first lab on Basic circuitry dedicated to resistive passive...
03 March 2016 9,594 90 View
As a rule, BJT output characteristics are presented as a family of particular characteristics representing the function of the collector current IC of the collector-emitter voltage VCE while the...
11 November 2015 6,666 10 View
In the laboratory of semiconductor devices, I suggest to my students first to measure the diode IV curve by the simplest and very popular "manual" setup - a potentiometer driving a network of...
10 October 2015 7,829 26 View
The basic activity of students In a semiconductor lab is to investigate IV curves of basic semiconductor elements (diodes, transistors, etc.). They can do it in various ways. The most primitive...
09 September 2015 9,100 5 View
It is said that we have to investigate the IV curve of a forward biased diode by a current source. But why? Why not use a voltage or even a humble real source (voltage source + resistor)? It is...
09 September 2015 9,684 11 View
As a rule, the BJT common-emitter output characteristics are presented as a function of the collector current IC of two variables - the collector-emitter voltage VCE and the base current IB; IC =...
09 September 2015 6,758 21 View
As a rule, the BJT common-base output characteristics are presented as a function of the collector current IC of two variables - the collector-emitter voltage VCE and the emitter current IC; IC =...
09 September 2015 6,184 13 View
Textbooks on semiconductor devices claim that the common-base configuration has greater output impedance than the common-emitter configuration. That means common-base output characteristics are...
09 September 2015 8,495 14 View
This autumn, I have to conduct with students of a new IT specialty a series of lab exercises related to study of basic semiconductor devices: ordinary, zener, light, tunnel and other diodes,...
08 August 2015 5,157 93 View
The best way to show the basic idea of a circuit is to build it step-by-step. I do this every year with my students at the beginning of the laboratory exercise about latches in the laboratory of...
01 January 2015 8,945 4 View
I have asked this question with two purposes - first, at the request of Barrie Gilbert to terminate the irrelevant discussions in the question...
12 December 2014 8,393 46 View
It is a great idea to see the connection between situations of our everyday life and abstract electronic circuits... If we can do that, it would allow us to understand and explain electronic...
10 October 2014 1,176 3 View
The long-tailed (differential) pair is another example of a an elegant simplicity. There is a lot of philosophy in this configuration that deserves to be discovered even almost 70 years after its...
10 October 2014 7,358 3 View
To build electronic circuits, first of all we need the natural electrical elements resistors, capacitors and inductors. However, in many cases we are not satisfied with the performance of these...
09 September 2014 9,971 20 View
Negative feedback systems compensate disturbances in the feedback loop by adding extra power equal to the power dissipated in disturbing elements. So they can be considered as negative impedance...
08 August 2014 1,205 78 View
The negative impedance concept is so attractive that some authors try to bring it on even the most basic electrical elements as voltage and current sources. See as an example the work of this...
06 June 2014 5,353 82 View
In all the op-amp inverting circuits (transimpedance amplifier, inverting integrator and differentiator, diode log and antilog converters, etc.), the op-amp compensates the voltage drop across the...
06 June 2014 9,374 101 View
What do diodes connected to (DL, DTL, TTL...) gate inputs do? In many circuit applications (diode logic gates, wired OR, auto alarms, buffered power supplies, etc.) a few voltage sources...
11 November 2013 4,448 21 View
We have already disclosed the basic idea of the historically first RTL gate...
11 November 2013 5,470 3 View
Can we believe it? Can we rely on them? And to what extent? Looking at Wikipedia from the outside (as a reader), it seems perfect with its highest Google rank. But here I want to look at it from...
11 November 2013 4,206 80 View
It is well known that Google puts Wikipedia pages on the first places in its results list, and for many people it seems that they are the best sources sought by them. But is this really so? From...
11 November 2013 5,123 26 View
When I first met the exotic RTL gate (see the attached picture), I was amazed since I could not imagine how it was possible humble ohmic resistors to perform logic operations. Until then I knew...
10 October 2013 6,245 15 View
I temporarily leave the “kingdom” of my favorite analog electronics and move to the neighboring field of digital electronics because this term I will conduct a series of labs in the laboratory on...
10 October 2013 4,911 17 View
We have already discussed reactive elements in the questions below but I have asked here this separate question to consider thoroughly the way they oppose input voltage sources when connected in...
10 October 2013 8,697 36 View
We had a problem with "negative resistance" since it represented two different types of resistances - "true negative...
09 September 2013 3,612 52 View
When we see somewhere written "negative resistance", we are never sure what exactly it is, just because it has two varieties - "true" and "differential"... and the former is not a resistance:) We...
09 September 2013 8,946 30 View
It is a common practice to consider the voltage divider as a voltage source, e.g. to say, "the circuit is supplied with a constant voltage by a voltage divider". Also widespread is the resistor to...
09 September 2013 4,458 41 View
I restore my participation in RG discussions by asking the next "naive question" about basic electrical phenomena from the Ohm's times. I can not figure out why I do it since, in fact,...
09 September 2013 1,290 70 View
Once virtually destroyed the ohmic resistance of a...
08 August 2013 3,871 3 View
Once we made various virtual “elements” as follows: * ammeter with zero internal...
08 August 2013 2,964 13 View
I remember that many years ago when I was a student and I had to construct an electronic measuring instrument with a simple movement indicator of how much I was deeply impressed by this extremely...
08 August 2013 4,872 34 View
We have already seen that negative impedance elements are amazing and extremely useful electronic devices...
08 August 2013 5,004 46 View
There is hardly so controversial, misunderstood and denied phenomenon in circuitry as negative impedance (resistance). Many questions can be asked about the mystical phenomenon: What is it? Is it...
08 August 2013 3,668 8 View
I continue to develop the powerful “voltage compensation” idea by asking more and more questions about its ubiquitous implementations. So far, we have considered how to virtually decrease the...
08 August 2013 4,998 10 View
From my experience, I have found that, in the most cases, circuit phenomena have dual versions: voltage - current, resistance - conductance, positive resistance - negative resistance, capacitance...
07 July 2013 2,090 83 View
We have already discussed how the AC current "passes" through a capacitor https://www.researchgate.net/post/Does_the_current_flow_through_a_capacitor_and_if_so_why?, and we have realized the...
06 June 2013 1,293 39 View
The extremely interesting and topical questions below were about the rift between digital and analog...
05 May 2013 8,691 20 View
To build electrical circuits, we need basic electrical elements. Unfortunately, there are only three natural electrical elements - a resistor, a capacitor and an inductor. That is why, in...
05 May 2013 4,745 2 View
Most of electronic circuits process data than energy, so they act as data converters. For some reason, the voltage is used more frequently than the current to carry the data (analog or digital);...
05 May 2013 915 39 View
Once answered what is "passive" and what "active" in...
05 May 2013 9,153 17 View
Actually, this topic is already started (by Dr. Abbott) in the question about the nature of the transistor:...
05 May 2013 3,664 20 View
I ask this question with the purpose to help answering the debatable question, "Does a true current source exist?" We continuosly come across it when discussing the questions about the basic...
05 May 2013 9,358 9 View
For some reasons, voltage sources are widespread in this world while it seems there are not true current sources. So, we should build them on the base of voltage sources. It is interesting to...
05 May 2013 4,232 43 View
This question is closely related to the question about the motivating students in the lecture...
04 April 2013 1,352 3 View
I have noted from my teaching activity through the years that the electronics education actually does not reveal the fundamental circuit ideas. As a rule, teachers begin explaining particular...
03 March 2013 8,914 12 View
This discussion is old as the very bipolar transistor... but it is still interesting... In my opinion, a BJT can be controlled either by voltage or current depending on the situation. If we want...
03 March 2013 2,692 101 View
Integrated circuits are built of many electronic elements connected in a circuit that is enclosed in a package. These integrated circuits are connected in various circuits. An example is an op-amp...
03 March 2013 9,404 4 View
After all the epic discussions-:) about the Wien bridge oscillator... https://www.researchgate.net/post/What_is_the_basic_idea_of_Wien_bridge_oscillator_How_does_it_operate ...I have finally...
03 March 2013 2,480 17 View
An amplifier with a differential input amplifies the voltage difference between the inverting and noninverting input. It seems it is possible to connect the input voltage source directly to the...
03 March 2013 3,108 35 View
I have extracted these questions from the discussions (leaded by Lutz von Wangenheim) about the Barkhausen criterion, RC oscillators and phase shift in RC circuits where we tried to answer the...
02 February 2013 4,400 100 View
It is considered that we may write the Ohm's law in three equivalent expressions that are used interchangeably - http://en.wikipedia.org/wiki/Ohm%27s_law#Circuit_analysis Really, from a...
02 February 2013 8,473 73 View
It is well-known that there is a 90 deg phase shift between the current and voltage in the capacitor (when supplied by a sinusoidal signal) and it varies from 0 to 90 degrees in the RC integrating...
02 February 2013 2,935 51 View
The Barkhausen criterion says that the circuit will sustain steady-state oscillations only at frequencies for which the loop gain is equal to unity in absolute magnitude and the phase shift around...
02 February 2013 8,199 42 View
I have extracted this general question from the more specific discussion about the validity of the Barkhausen criterion in the circuit of a Wien bridge...
02 February 2013 2,131 19 View
The two's complement code is well described, see for example: http://en.wikipedia.org/wiki/Two's_complement But it is interesting to show the basic idea behind this clever "trick".
02 February 2013 9,190 5 View
The Wikipedia says: "To convert from a base-10 integer numeral to its base-2 (binary) equivalent, the number is divided by two, and the remainder is the least-significant bit. The (integer)...
02 February 2013 1,826 5 View
I have asked this fundamental question, since we have frequently come across it in the discussions about the RC phase shift, RC oscillations and Barkhausen...
02 February 2013 4,442 94 View
Both the virtual and real ground have the same potential (voltage). It seems they can be connected together.
02 February 2013 4,471 39 View
I dedicate this question to my students from Faculty of Computer Systems and Technologies of TU Sofia, groups 44 and 45, May 2019. Last Wednesday, after the lecture on diode circuits, an...
01 January 1970 2,371 27 View
