Loading can be 100kΩ and 10k conversion rate. Everything looks OK. So I can start programming. The first function is to setAnalogOutputVoltage().  4 hours later… Circuit fantasistFri 19:02Interesting… I wonder if there is such a high speed scope to see the trajectory of the operating point during the jump… tlfong01Fri 19:25I guess we should ask the physics blokes: physics.stackexchange.com/…  9 hours later… Circuit fantasistSat 4:26There is an interesting question there – Differential resistance vs. R = V/I. I would prepare an answer for it…  7 hours later… tlfong014886Sat 11:30Ha, I am anxiously waiting for your answer. In the mean time, I am writing my comments:
tunneldiode.blogspot.com/2020/…The question reminds me of my questions (meaning of “dynamic”, “differential” etc) to the OP’s question on negative resistance, using MOSFETs, LTspice etc. If he does not even know basic calculus terms “differentiation”, “integration” etc) then we are wasting our time. BTW, the ADC PCA8951 can config with 4 “differential” input channels, but the two “differential” term using in tunnel diode and ADC is completely different, so we need to point out the differences.As I said from the very beginning, using a lab case study with real things 2BS4 and PCA8951, show them the I-V curve on the scope, also with measurements/readings with DAC and ADC should clarify many confusions and ambiguities etc.  4 hours later… Circuit fantasist5417Sat 15:53Hi! They are different concepts. In a differential amplifier there is a difference between the voltages applied to two points (inverting and non-inverting input); in the differential resistance there is a difference between two values of the voltage applied across a dynamic resistance.Why don’t you ask a question in Physics about point 2 in the Khan chart? I will answer after that and explain that there is no such point … It is possible that the situation there is more friendly … tlfong014886Sat 16:12@Circuitfantasist Yes, The naming or terms in op amp and tunnel diode are confusing. Let me ask you some basic question to warm up. I will first ask questions about op amp, then later about negative resistances.Question 1: What is the meaning of “Operation” in “Operation Amplifiers”? When I studied my EE diploma, I knew why “pre” amp, “power” amp are called their names, but what is hell is “operation”? Do all your students know the answer?Ah, I hesitated to ask the “Point 2” in EE SE Q&A, because the so called elites and moderators there are very professional engineers. I have the feeling that look down upon EE diploma holders and gave me unfriendly comments such as (1) “@tlfong01, your question is not useful in our party, … “, (2) “@tlfong01, you are not “knowledgeable in enough” (or a more harsh word or warning” I forgot) to contribute to answer for question, … (so I immediately make apologies, …).I have never asked any questions in this EE SE Q&A forum, but I guess I made most apologies in this forum, and most down votes, and most closures on my answers (more about my bad experiences here later). So I need to take up courage to go to a new place like physics.se and ask a question, …As I said earlier, I need to read Prof Kahn’s tutorial and understand thoroughly before I ask a question on “Point Two”. I will try to ask that question perhaps tomorrow. tlfong01Sat 17:24Now I am compiling a reading log of Prof Kahn’s lecture: tunneldiode.blogspot.com/2020/….Ah, jogging and supper time. See you late this evening or tomorrow. Cheers.  1 hour later… Circuit fantasist5417Sat 18:38Hi TL Fong! In the past, op amps have been used to implement mathematical operations in analog computers; hence the name “operating”. Today it is synonymous with “quality”, “perfect”, “almost perfect”… Hmm … very precise observations on the nature of the “elite” in EE. I also have rich observations and practice in this field … I can say that I have become almost a psychoanalyst … and a psychotherapist 🙂This morning, I published another paper in Codidact. It is about the philosophy behind current sources. I think it would be interesting for you.  4 hours later… tlfong014886Sat 23:06@Circuitfantasist I have summarized another post on “Point 2”: tunneldiode.blogspot.com/2020/…I have no idea on how to ask the Point 2 Question. Should I ask something like this: “I have read the article by Poole and Darwazeh, I don’t understand why Point 2 is unstable?” But this seems to be a silly question. Or you may like to comment on my second Point 2 post and let me know what goes wrong!@Circuitfantasist Thank you for your answer. Your mentioning of the word “Mathematical” is most critical to me. All these years, I did not know what “operational” refers to. I never realized that it is mathematical operations (addition, subtraction, and most importantly differentiation and integration), because nowadays everybody used digital mathematical operation, no longer “analog mathematical calculation@Circuitfantasist You new article “Philosophy behind current sources” if a bit too hard for me. Perhaps I should read it again sometime later. It is only two weeks ago I had an application that I need to use a current source, and I did “invent” or “discover” a particular kind of current source. Perhaps more about this later.Ah too late to go to bed. See you tomorrow or later. Cheers.  3 hours later… Circuit fantasist5417Sun 2:42Hi, TL Fong! I have fabricated a question and written it in your blog. Of course, I can ask and answer it but the “elite” will be dissatisfied… and we should not irritate it… Also, try to imagine the trajectory of the operating point that it travels when it “jumps” from point 3 to point 1. Regarding current sources, I suggest to you to consider your specific circuit solution of a current source from the perspective of my philosophy…  9 hours later… tlfong014886Sun 11:56@Circuitfantasist Yes, many geeky elites are not very good in, as you say “transferring knowledge”. I remember when I studied my rusty EE diploma ages ago, I learned the subject “Presentation of Technical Information” (And also “Engineer in Society” – a compulsory subject in CEI (Council of Enggr Institutions).So from time to time, actually day after day, again and again, I tell the geeks what they don’t know that they don’y know. This is an example I am doing it yes, again, this morning: raspberrypi.stackexchange.com/…. Happy Q&A reading. Cheers. tlfong014886Sun 12:31In today’s “Geeks don’t know what they don’t know” example, I show how to guide the OP by giving an example of how to troubleshoot, how to write a SO recommended MCVE (Minimal, Comprehensive, Verifyable，Example) program examples, from step, …, My answer, as I pointed out, “hit the SO/SE answer limit of 30,000 words”, so I have to trim it down. I do have a couple of such answers hitting 30k word limit, and it is not uncommon that I got 0 up votes, and the most envied answer got 7 down votes.Some of my answers got “delete vote” even before I have written my introduction paragraphs. BTW, my grandmother used to tell me: “If nobody envies you, that means you are just an “ordinary” kid, …”. So I do see my three down vote answer as a bronze badge, five down vote answer a silver badge, and seven down vote answer a gold badge. Now tell me, how many down voting badges have you got so far?And you see my long winded 30k word answer still got zero votes. I also often have long chats (up to two week or so, or until the OP’s college assignment deadline is near) with the OP：
chat.stackexchange.com/rooms/…，before I am satisfied that the OP understood my explanation. I am not complaining, and I am really enjoying being down voted. 🙂 / to continue, …  4 hours later… tlfong014886Sun 16:51Hi, now I have found the critical points. I have no idea how to move on.

Jogging and lock down supper time. See you late this afternoon or tomorrow. Cheers.  4 hours later… tlfong014886Sun 21:15About your comment of “observations on the nature of the “elite” in EE”. Actually I have been watching SO/SE for a couple of years, and I took part in all SO surveys and from time to time talk to moderators, community staff and participate
in meta sites. I do think I always badly irritate the elites. You might see the reason in my comment to the following article:
Down votes and unfriendly Badges! – Jon Ericson, Community Manager (former) 2019jun18
stackoverflow.blog/2019/06/18/…(see full text)  9 hours later… Circuit fantasistMon 6:20TL Fong, Valuable thoughts with a lot of wisdom… I will answer to you tomorrow since today I had some problems…  3 hours later… tlfong01Mon 9:16As I said, I have been browsing a couple of forums to compare and contrast their management and award schemes. I am on the CD’s mailing list on meta things: In case you have not read already, this CD　article is worth reading: “Codidact’s New No Badge System” meta.codidact.com/articles/…  3 hours later… tlfong014886Mon 12:21As you suggested, I am considering posting a question in physics.stack exchange. So I am browsing the tunnel diode Q&SA’s there (about 40+) My first impression is good. The people there seems “decent”. I read their profiles and found them interested in learning, and not in making money: I have made a summary for my future reference. tunneldiode.blogspot.com/2020/…I found that I have forgotten many basic semiconductor physics and technology terms when I studies the subject. So I think I am not yet “able” (in CD’s terminology), or have the prerequisite knowledge to understand the discussions there, not to mention asking question. So I will stall the Q&A part, and go back to do my real word experiments. This reminds that in our deleted CD discussion, I mention the MIT’s way is learning by doing, and Edision’s quote on failures.BTW I am showing my way of reading, learning, thinking, experimenting in my blog tunneldiode.blogspot.com, to show the newbies how I am learning to be a hobbyist engineer.  3 hours later… Circuit fantasist5417Mon 15:14Hi TL Fong! I compHeavy snow is falling here. I’m in the car looking at what you’ve written.I completely share your opinion on the negative votes. I even thought to warn readers to interpret them in the opposite sense – the more they are, the higher reputation I have … Circuit fantasist5417Mon 15:30I would like to ask you about the blog as another tool for saying what you know… As far as I can see, it’s like a diary that shows your thoughts chronologically …… and your development and progress …I like this because I like to illustrate circuit ideas through my thinking as a concrete example … I do it by “building” and “reinventing” scenarios…  18 hours later… tlfong014886Tue 9:41@Circuitfantasist Well, in some forums, you have little privilege if if you have low reputation points. So I very soon realized that the elites can do many things I never dream of, like monitoring user, me answering in real time, and delete the whole question before I complete my first sentence, or close it after my answer. So I usually do not start answering before the elites does and gets their upvotes, …So I am glad to learn that CD is making a change, removing the reputation points scheme by ‘ability’ points and let the newbies to have many privileges, so not feeling being cyber bullied, …Anyway, I still have not though about how to fix the unstable Q point in the mysterious NDR region, though I now have a better idea of the load line, but not yet good enough to analyse and design a load time to oscillate the tunnel or catch the electrons crossing the quantum tunnel.I did read some guys suggesting to use an inductor to forbid the electrons to jump over (current suddenly decreasing), so the naughty electrons can only walk slowly after reaching the Ipeak, and crawl slowly down hill and stay steadily at the Q point of the load line. The GE62 TD guide says we need to choose the Rd carefully, otherwise circuit won’t be stable, … Perhaps I should explain in more details my test plan in another post in tunneldiode.blogspot.com. tlfong014886Tue 10:20BTW, when visiting Physics SE, I found #***The photon*** in the tunnel diode discussions. I thinks his answers are good. So I should pay more attention to his answers to learn more about tunnel diode: (1) electronics.stackexchange.com/…
(2) electronics.stackexchange.com/…tlfong01Tue 10:57Now I have found a reference on TD 2BS4A load line analysis and astable design. Any comments? tunneldiode.blogspot.com/2020/…  1 hour later… tlfong014886Tue 12:22About my tunnel diode blog – I am suing the free Google blog service called “Blogger”. You can see that I have a couple of other old, out of dated Blogger blogs, mainly on Rpi experiments. These couple of years I am using rpi.org/blog. It is good for projects: Relay Module KY-019 5V – tlfong01, http://www.raspberrypi.org/forums/projects/automation,sensing, and robotics
raspberrypi.org/forums/…. The good thing of this kind of project blogs is (1) You can start a project, or just exploring something, say, I did not know anything about relay, so I joi…(see full text)  9 hours later… Circuit fantasistTue 21:45Hi TL Fong, Today I had very little time and I could only look at some of your links …I have a lot to write to you but the time difference prevents me from doing it on time… tlfong014886Tue 22:24No worries. Nothing urgent actually. Take you time. I am right now trying to set up my new Raspberry Pi (CM4) It might take me at least one hobbyist week to complete. I am also programming the DAC PCA8951 to do a DC sweep to power the tunnel diode, it might also take me another hobbyist week. So just wait till you have more time to comment on my posts. Have a nice day. Cheers.  2 hours later… Circuit fantasistyst 0:26Interesting observations on the behavior of the “elite” … I also observe how certain groups consolidate against the “common enemy” and help each other … All this is unworthy and insulting because we are here led by good will … Circuit fantasist5417yst 0:52This started to make me nervous and I am already thinking about what I can change. I realize that you have to have something of your own so that you don’t feel like a “guest” in a foreign place.I have a site since 2002 (circuit-fantasia com) but I no longer want to keep it at a low level (html). I am looking for a simple form to publish my ideas. Wikibooks is a rather cumbersome publishing system and has no feedback from readers. Discussions in ResearchGate are weak. Question&Answer sites like this one allow some awful people to make fun of you in all sorts of ways. The new site has restrictions …  2 hours later… Circuit fantasistyst 2:41Your blog caught my attention as another possible form of publication. But the organization is not very clear to me. Can individual publications be followed only chronologically? Or does this apply to posts inside? Maybe I should try …  8 hours later… tlfong01yst 11:09@Circuitfantasist Ha, I don’t see “All this is unworthy and insulting”. I find meeting terrible, but not too stupid guys exciting, healing, and enjoyable. Haven’t you read any articles about the reputation of SO and SE? – tunneldiode.blogspot.com/2020/…. Nothing urgent, no need to reply, unless you are very free.  5 hours later… tlfong01yst 16:11@Circuitfantasist You might like to read some reviews, but most of them are commercial ads (there isn’t anything called free lunch!). If you just want to try to test the waters, I would recommend the free Blogger, which is what I am using for tunneldiode.com. You might also like to skim my post below. tunneldiode.blogspot.com/2020/…  1 hour later… Circuit fantasist5417yst 17:24TL Fong, Exactly… I think the free Google blogger is the best solution… I would like to ask you about the internal organization. I can make a few sections: Circuit stories, SE Q&A, RG questions, etc. How will they appear – as different blogs, pages, posts or something else? Will I be able to move them and insert them into each other? In other words, can I structure the content?Your links make me think about more and more things and realize them. I think we have a need for an open discussion forum. Indeed, these Q&A sites are very limited … But they give very interesting ideas to discuss… Circuit fantasistyst 17:58Here’s what I’m doing right now – photos.app.goo.gl/…  5 hours later… tlfong014886yst 22:36@Circuitfantasist Just a quick reply. You can have 100 free blogger accounts. So I have tunneldiode.blogspot.com for tunneldiode, and perhaps zenerdiode for another one, and schottydiode for yet another one. But many names might have registered. So you might pay for a domain name such as circuitfan.com, then you can have negativeresistance.circuitfan.com etc, …I guess you can have an hierarchy of accounts/blogs by assigning a blog to point to lower blogs, like those eCommerce blogs. I am using “pages” to do som classification, and also “labels” sort of tags, for easy searching. But I am not keen to promote my blogs. As you said, contents important. If my blogs are easy to google search, then those interested should google and find me.Ah, bed time. See you tomorrow.@Circuitfantasist Ah, you graph paper drawings are very old school. I would suggest to use the free Circuit Lab schematic drawing tool, which is built into SO and SE. The good thing is you can share the schematic on the internet. Anyway, bye.  2 hours later… Circuit fantasist54170:22So, what are “FongEye”, “FongMcu”… “Tunnel Diode”…? Are they separate blogs (blogger accounts) for the same person? I thought the name of the blog was the name of the person. What requirements must a blog name meet?But I think the idea is clarified thanks to your explanations…  2 hours later… Circuit fantasist54172:04About my old drawing technology … you can say the same to Bob Duhamel … but as you can see, he uses an even more primitive tool – a whiteboard and a marker … About my old drawing technology … you can say the same to Bob Duhamel … but as you can see, he uses an even more primitive tools – a whiteboard and marker … There must be some reason for that …Very annoying that you can’t edit your comment …  1 hour later… Circuit fantasist3:14Done! photos.app.goo.gl/…And the application – photos.app.goo.gl/…Sorry, this is the idea – photos.app.goo.gl/…Circuit fantasist4:17I have created my profile page and five blogs. It does not allow me anymore (is that the limit?)blogger.com/profile/…  5 hours later… tlfong0148869:06Just a quick reply.(1) I visited circuitfantasiastories.blogsp…. I only saw an empty web page. Perhaps you forgot to click the “publish” button at the very top right corner.(2) About Bob Duhamel’s white board and marker. Well, if you browse MIT’s very recent youtube lectures, they are using black board and white chalk. But everybody thinks it is OK. Perhaps I should not say you technology is outdated. It is only the symbols and current flow and voltage potential/polarity which is unconventional or out of date.(3) I noticed you already have your domain name “circuit-fantasia.com”. Then you can open 100 “accounts” or blogger sites such as “mystories.circuit-fantasia.com“. But if are not using their brand name “blogspot.com”, they might charge you a fee. Cheers.  1 hour later… Circuit fantasist10:40TL Fong, I have created 5 empty (for now) “blogs”… I want to create more (e.g., wikibooksstories……..) but it does not allow me anymore… Circuit fantasist541710:50What is not OK with my way of graphical presentation? The only different things are the meaningful letters “D” and “T” that I use to designate diodes and transistors instead the meaningless “Q”…… My circuit diagrams are conceptual; their role is to show the basic idea behind the circuit… not how to implement a specific solution. Voltage bars and current loops are my specific tools visualizing the invisible electrical quantities voltage and current. Should I explain all this to you? I think I should if you were Olin… tlfong014886Well, I would suggest you to test the waters by messing around just one blogger site first. Often free site won’t let you be overambitious to start with too many things at the beginning. I checked my record and found that I open a couple of sites some time in 2008, and then stopped when I heard Google discontinued there services such as Google+, Google hangout etc.These couple of years I just wandered in a couple of sites such as All About Circuits, Rpi.org.forum, and only recently Rpi SE, EE SE, Robotics SE etc. It is only a couple of days ago I reopened my google blogger site, but found they changed their user interface a lot, so I need sometime to catch up. I also joined other Chinese forums on and off these years, but too lazy to do maintenance, … Circuit fantasistcircuit-fantasia.com is the domain of my site that I create in 2002. I pay $ 50 each year for Seanic’s hosting and domain. But I don’t see the connection between it and this blog. Do you mean it?(domain name) tlfong014886@Circuitfantasist As I said, then you can have something like mystories.circuit-fantasia.com, “negative-resistance.circuit-fantasis.com, etc, if you are still paying USD50 a year.@Circuitfantasist I understand you saying that “My circuit diagrams are conceptual“, but there is big problem, you strange notation are chasing away the readers. Now it is the Tik Tok Generation, nobody would bear with you more than 15 seconds to first listen to you the introduction to your strange notation.Perhaps you can upload an introduction to your strange notation as a Blogger blog and I will comment there to suggest how to pull you chased away audience back, perhaps using Circuit-Lab schematic drawing, with colour coded arrows, to denote current flow and voltage polarity/drops. Ah, I missed my tea. See you later. Circuit fantasist541711:25I still can’t understand what is my “strange notation”. What you are talking about? Voltage bars (the “red lines” as Olin contemptuously said in his only comment below my articles) and current loops? If so, yes… it is strange since it is something original. Every new idea is strange for the conventionally thinking (or simply “non-thinking”) people… I do not want to use “arrows”; I want to use exactly bars and loops… tlfong01488612:10@Circuitfantasist Yes, I agree that you CAN use innovative bars and loops. But I think you SHOULD, at least for now, use traditional representation if you don’t wish to chase away your audience. As I said earlier in CD, I have no problem understanding you strange notation, it all boils down to physics, and then mathematics, and then philosophy. I rembember I mention Emma Noether in the beginning of this chat.I have cut the pictures uploaded here, and I am going to move them to tunnediode.blogspot.com. I suggest we carry on our discussion there. tlfong0112:24@Circuitfantasist I have post something to begin our discussion on circuit analysis and synthesis: tunneldiode.blogspot.com/2020/… You might also like to post something at you circuit story in you blogger site.Ah lunch time. See you later. tlfong01488612:46I am googling more tools to design the tunnel diode oscillator. I have little idea what inductors and resistance to use to oscillate the tunnel diode. I am reading an I2C impedance converter datasheet to get some idea:
tunneldiode.blogspot.com/2020/…. I am thinking that the tunnel diode with external inductance is sort of RL impedance. Sot this converter chip might be useful in the oscillator design or measurement. I dont quite understand the DFT operation. So experimenting with the real DSP chip might help understanding better.(see full text)  8 hours later… Circuit fantasist20:26I am temporarily stopping because I need to get organized …  1 hour later… tlfong01488621:46No problem. As I said, take you time. It is a long project. I might take as least two weeks to sort out the PCA8951 ADC DC sweep sig gen, and Rpi CM4 setup. I learnt the tortoise and rabbit race story. My grandmother always tells me “If you want to go too fast, you won’t arrive”. As I told you, I started my couple of Blogger sites in 2008 .And on and off, I messed around with perhaps 10 more other blog sites. So you might might need perhaps at least a couple of weeks to catch up. Have a nice weekend. Cheers.