Discussion between tlfong01 and Circuit fantasist

1:06 AM

@Circuitfantasist (1) Before I reply, I would like to suggest that we click the down arrow on left of the article we are referring.

(2) One of my many reasons of visiting EESE and other forums (Yes, I have been hopping among more than a couple of forums every day), is to mend my broken English. Me on average, meet more than one new word everyday. This morning I learned a new word - "Erudition".

To learn a new word, I usually first goggle, skim a couple of dictionaries, and finally Wikipedia. Wikipedia says the following.

Wiki - The word erudition came into Middle English from Latin. A scholar is erudite when instruction and reading followed by digestion and contemplation have effaced all rudeness, that is to say smoothed away all raw, untrained incivility, ...

Meaning
Erudition is the depth, polish and breadth that education confers. The Latin word educāre means to bring out or train; hence an educated person has come to think critically and logically. An erudite person has both deep and broad familiarity with general subjects and is usually knowledgeable in a particular subject, by virtue of study and ext…

About "Erudition", I can easily write a boring article of 30k+ words. But for now, let us chat something more interesting, that is "How can you and me, and EESE specifically (never mind generically), attract more "followers")

@Circuitfantasist You said this: "... around me are IT students who do similar developments in their diploma theses, some very interesting. Obviously, this is the spirit of the new age... and we, "old warhorses", only keep the wisdom of the past." -

You remind me that I am a sort of freelance/slash teacher in computing science/computer engineering in industry (ie, the factory gave me the engineer, an assignment give a schedule of a series of talks of to teach the technicians and other engineers), let me, see, 1, 2, 3, 4, 5, 6, ah, I lost count, should be about 8 to 10, ... :)

Don't ask me how many colleges and uni's I studied, because I would lose count again, should be around 8, including two dropouts.

I also from time to time, proposed / monitored / moderated / sponsored/interviewed / examined undergraduate level, individual/group term/year projects, including BCS (the British Computer Society then) Part 2 Qualification Project (sort of by practical project thesis/report)

Yes, I am an erudicated guy, as our Chinese saying go: (1) gentleman hide deep and won't show off, (2) People don't know (that you know that much), but you could care less (because they don't know what they don't know (about knowledge you know).

But there are times you should show your knowledge, skills, and experiences, to help/guide/mentor the young ones what you think is a good direction. When I was young, I did received help from the old guys, who I always think I should be grateful and so it is time for me to pay back.

So you suggest: "Old warhorses, ... only keep the wisdom of the past,". This I don't agree. I will explain, and I am going to propose projects for your students in the form of Q&A, in EE SE.

Ah, morning coffee time. So see you later, perhaps after lunch, late this afternoon or evening. Nice chatting to you. cheers.

tlfong01

2:43 AM

The Intern 見習冇限耆 - Official Trailer - 2015may13, 9,845,830 views
https://www.youtube.com/watch?v=ZU3Xban0Y6A

I heard the following MIT AI Corona Virus App news from BBC Radio this morning.

Artificial intelligence model detects asymptomatic Covid-19 infections through cellphone-recorded coughs
Results might provide a convenient screening tool for people who may not suspect they are infected.
Jennifer Chu | MIT News Office Publication Date:October 29, 2020

https://news.mit.edu/2020/covid-19-cough-cellphone-detection-1029

tlfong01

3:21 AM

My literature research :)

COVID-19 Artificial Intelligence Diagnosis using only Cough Recordings - digitalreality.ieee.org
https://digitalreality.ieee.org/images/files/pdf/COVID-AI-Diagnosis-using-Cough-Recordings.pdf

DOI 10.1109/OJEMB.2020.3026928, IEEE Open Journal of Engineering in Medicine and Biology (Creative Commons Attribution 4.0 License)

tlfong01

4:11 AM

Now I have assembled a poor man's cheapy Covid-19 AI cough recorder and real-time analyser.

@Circuitfantasist "the idea behind op-amp inverting circuits, negative "resistors", ... I can share it with you ...". Ah I am only an op amp newbie. I learned op amp stuff when I studied my rusty EE diploma ages ago, but my work life since then have been all digital.

I used to think that analog stuff is useless and has already been replaced by digital. But now I have a problem, I am calibrating a 100g load cell, with 0.01g accuracy. I am trying to use a 24-bit load cell amplifier, the HX711 to do the ADC. However the load cell output is of the range 0mV to 5mV, and though HX711 do handle the tiny signal, but it is slow 16sps.

So I am thinking of using an op amp to amplify the signal and do some realtime processing, perhaps using JetsonNano with AI neural net stuff, to analyse the coughs of Covid-19 guys. I have only recently started the project, originally for testing a wind tunnel. But the wind tunnel project failed, so I started again, switched to Covid-19 coughing analysis, hoping to attract more "followers".

This is a recent progress report of the failed wind tunnel project, in case you are interested:

Discussion between tlfong01 and Cem

Imported from a comment discussion on raspberrypi.stackexchang...

tlfong01

6:54 AM

@Circuitfantasist I am a little bit confused. (1) I know "normal resistance" is "Ohmic", means that R = V/I is more or less a constant, or I vs V is "linear". (2) I also know that semiconductor devices such as a diode is "non linear" or "exponential".

(3) I also know that "dynamic" is time varying. (4) I once played with NTC (Negative Temperature Coefficient (NTC), where R vs I is linear but gradient is negative. When I increases, T increases, R also increases, and I decreases (V constant, a step function or an impulse function). So NTC it is sort of dynamic, because I changes as R, T changes.

My "negative resistor" electronics.stackexchange.com/questions/528419/… looks like this:

Now I have a couple of questions: (a) In defining or specifying you negative resistor characteristics, what are the (i) dependent, and (ii) independent variables? (b) Do you have any defining equations or graphs to illustrate your negative register idea? (c) How is your negative resistor different from the NTC resistor?

tlfong01

8:31 AM

I can suggest Covid19 student projects in this EE SE Q&A. I usually visit various college project site to see what is going on there. This is one of the sites I regularly watch inspire me hobbyist project ideas: Cornell University ECE5725 Spring 2018 Rpi Student Group Projects
https://skovira.ece.cornell.edu/student-projects/

If your students are mainly doing individual and not groups, spending time shorter than a semester, or EE minor students not so experienced in ENC/MPU/SBC, you can split a big project into small parts to make it more newbie friendly. For example, for the Covid19 cough analysis project, you can split it into the following parts: (1) Cough capture, using linux audio utilities with microphones, with low resolution ADCs, such as MCP3008/3201.

(2) Use Rpi4B and TensorFlow Lite to play with Google supplied classic basic test patterns such as recognizing numerical "0", "1", "2, ... "9" etc.

I have a couple of Covid19 related project ideas: Here is one:
How can Rpi read the MAX30100 / MAX30102 Oximeter? Rpi EE, 2020may01, Viewed 2k times
https://raspberrypi.stackexchange.com/questions/111955/how-can-rpi-read-the-max30100-max30102-oximeter

I have also played with air pumps, air flow meter, high torque serial bus servos (LX-224) for Covid19 related projects like this: "Coronavirus: Raspberry Pi-powered ventilator to be tested in Colombia - Zoe Thomas, BBC 2020apr13"
https://www.bbc.com/news/technology-52251286.

Ah, jogging time. See you late this evening or tomorrow, Cheers.

tlfong01

9:26 AM

Before I go, let me comment on your Q&A: Circuit Phenomena Have Dual versions - Cyril Mechkov, Technical University of Sofia, 2013jul07,
https://www.researchgate.net/post/What_is_current_steering_and_how_is_it_implemented_Is_there_a_dual_voltage_steering_If_so_what_is_it_and_how_is_it_implemented2.

You said the following: "Circuit phenomena have dual versions: voltage/current, resistance/conductance, positive resistance/negative resistance, capacitance/inductance, positive feedback/negative feedback, amplifier/attenuator, integrator/differentiator, low-pass/high-pass, series/parallel, etc... "

I am relearning op amp, and I am focusing on op amp integrator and differentiator and you idea of dual phenomena is helpfully inspiring to do a "deep learning" of the op amp. Usually I think of unthinkable things while jogging, and DUAL is the subject of my jog this time. Cheers.

tlfong01

1:56 PM

I suggest the MIT AI Cough Covid19 test for the following reasons. The discrimination between positive and negative Covid19 is much easier, and takes less computation power than discrimination of 10 sounds say "Zero", "One", "Two" ... "Nine". A start off warm up project might be just a humble discrimination between two classes, child and adult etc.

Circuit fantasist

6:06 PM

@tlfong01 @tlfong01, I am beginning to respond consistently to your comments because today I was finishing my second "inventive" article on Codidact (electrical.codidact.com/articles/278933) and only now I find time to write to you. Just to ask you, because I have no experience in chats, is it normal to chat here indefinitely? Maybe it would be better to do it in the right places - below the appropriate questions and answers?

Circuit fantasist

6:49 PM

Regarding "common collector"... I see what you mean but it is better to say "open emitter". "Common collector" is reserved for AC (small-signal) applications when the base and emitter voltages vary but the collector is firmly fixed to VCC. Here we are talking about digital applications where the base voltage is fixed at zero or VCC.

@tlfong01 To "(1) He knows the answer already, but does not want to tell. If that is the case, then he is not honest, (2) He does not know the answer. It that is the case, then he is stupid,..." add (3) He knows the answer already and he wants to tell. This is my case.

Circuit fantasist

7:07 PM

@tlfong01 I know I have to use simulating software but I do not use it for a variety of reasons. First, I have to work hard to master it so that it is useful to me. Second, I know I am going to start thinking less about circuit phenomena. Third, it will reduce my enjoyment of mentally finding a solution. But sometimes I do some real experiments to test some of my assumptions.

Circuit fantasist

8:43 PM

@tlfong01 Saying "philosophical" I mean "conceptual", "generalized"... Most people think specifically and do not make a connection between the individual specific implementations of the same idea. As the saying goes, "they can't see the forest for the trees." Understanding a circuit requires seeing the general idea behind it.

Circuit fantasist

8:55 PM

@tlfong01 I got a good idea of you. I have always been interested in how programming combines with technology (software with hardware)... since the former is abstract and the latter so tangible. I am much more limited and all my life I only deal with circuits...

@tlfong01 These op-amp resources are good but standard. I need more in-depth explanations from people who have a "philosophy" and want to share it. Unfortunately, I can't find any, so I've been trying to make it myself for years.

@tlfong01 24-bit ADC sounds fantastic. I just can't imagine such a resolution. But I don't think you can use all its bits because of the interference.

@tlfong01 Regarding Sparkfun op-amp tutorial... Look at the inverting amplifier. Do you understand what is the need of R1 and R2? I was trying to answer this question as a student in the middle 70s (en.wikibooks.org/wiki/Talk:Circuit_Idea/…

Discussion between tlfong01 and Cem

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Discussion between tlfong01 and Circu…