On 10/08/19 15:56, John Larkin wrote:> On Sat, 10 Aug 2019 15:38:39 +0100, Tom Gardner > <spamjunk@blueyonder.co.uk> wrote: > >> On 10/08/19 14:47, John Larkin wrote: >>> On Sat, 10 Aug 2019 08:11:49 +0100, Tom Gardner >>> <spamjunk@blueyonder.co.uk> wrote: >>> >>>> On 10/08/19 01:55, Winfield Hill wrote: >>>>> Plus, when you have an analytical >>>>> solution to your circuit, you can more easily see >>>>> what the trade offs are, and optimize the circuit. >>>> >>>> That should be writ large, and engraved in all >>>> university courses. >>>> >>>> Unfortunately it is becoming a lost art :( >>> >>> Learning classic circuit theory and analysis is critical to doing >>> original circuit design, but it's just the starting point. >>> >>> Design is the opposite of analysis. And most all the interesting stuff >>> is seriously nonlinear. >>> >>> What the theory can do is provide insight, guide creative fiddling. >>> Ultimately most of us solder parts to boards to make stuff that works, >>> not publish papers. >> >> Completely understood and accepted. Anything significantly >> non-linear virtually requires number crunching rather than >> standard analysis. >> >> Nonetheless, an analytical solution to a /simplified/ model >> can yield valuable insights. The classic simplified model >> in physics is exemplified by "...assume a spherical cow...". >> >> There are many similar things in electronics, e.g. simple >> model are used to estimate EMI/EMC between one comms system >> and another. Imperfect? Of course; it never matches reality. >> Useful? Yes. > > Circuit design starts with the topology problem: what is the schematic > that we want to analyze? Where does it come from? > > In my EE school, when I talked about designing things I was told > "Undergrads don't design; that starts in graduate school" so I didn't > apply for grad school.Bizarre. Objectionable. My alma mater continues to have a completely different tradition, 40 years later. They have extremely well equipped labs, and the undergrads use them at any time for any project, including personal projects.
AoE x-Chapters, 4x.26, MOSFET current source, nodal analysis
Started by ●August 9, 2019
Reply by ●August 10, 20192019-08-10
Reply by ●August 10, 20192019-08-10
On a sunny day (Sat, 10 Aug 2019 06:52:59 -0700) it happened John Larkin <jjlarkin@highlandtechnology.com> wrote in <9uitke92j0216tpuapdrdrodfl1krbefnu@4ax.com>:>On Sat, 10 Aug 2019 03:05:57 -0400, Phil Hobbs ><pcdhSpamMeSenseless@electrooptical.net> wrote: >> >>Comma splice alert! ;) >> >> >>Cheers >> >>Phil Hobbs > > >From wiki: > > >Brother Cadfael is the main fictional character in a series of >historical murder mysteries written between 1977 and 1994 by the >linguist-scholar Edith Pargeter ... > > >That's funny. Her continuous comma splices make the books almost >unreadable. >Never heard of Cadfael, but did watch Catweazel in the seventies. https://en.wikipedia.org/wiki/Catweazle he is the inventor / embodyment of "elec-trickery" (electricity) and the "telling bone" (telephone) https://www.imdb.com/title/tt0063881/mediaindex Have to think of his way of seeing things a lot...
Reply by ●August 10, 20192019-08-10
"Tom Gardner" <spamjunk@blueyonder.co.uk> wrote in message news:PFA3F.982900$j33.789547@fx26.am4...> Nonetheless, an analytical solution to a /simplified/ model > can yield valuable insights. The classic simplified model > in physics is exemplified by "...assume a spherical cow...". > > There are many similar things in electronics, e.g. simple > model are used to estimate EMI/EMC between one comms system > and another. Imperfect? Of course; it never matches reality. > Useful? Yes.Don't read into it too deeply. JL is not so talented at analysis, and forgets not to project his capability onto others. The better lesson would be to work to your strengths, whatever they are; if they are analytic, then work on that. If not, work on faster methods of failing. Note this traditional phrasing is as much derogatory as it is celebratory. Indeed, some problems provably do not have closed analytical solutions, so one of your better bets is simply cranking out attempts and picking the better results. Thus, failing often. Which, again, is no excuse to check ones' brain at the computer. Problems can always be done smarter. Compare, say: the Leibniz formula for pi (the alternating harmonic series, which sums to pi/4), which converges extremely slowly; versus, the observation that the partial sums of that series alternate around the final value, so, wouldn't it be great if we could stick together pairs of terms with a properly tuned weighing factor and get much closer to the true result in far fewer steps? Applying the Newton convergence transformation gives a stupendous efficiency improvement (thousands of terms for a few digits vs. about as many digits as terms evaluated). Is it better to run LTSpice for several hours, or sit with pad and pen for several hours then check the result in ten minutes of simulation? If the result is equivalent, it doesn't much matter for engineering purposes which one did it. Limiting yourself to just one approach is the real problem. Tim -- Seven Transistor Labs, LLC Electrical Engineering Consultation and Design Website: https://www.seventransistorlabs.com/
Reply by ●August 10, 20192019-08-10
"Jan Panteltje" <pNaOnStPeAlMtje@yahoo.com> wrote in message news:qimm3k$c6b$1@dont-email.me...> > What security hole? > It '&' is just part of the bash syntax and means run program in the > background. >I made the not-unreasonable assumption that your text formatting woes are due to a backwards, outdated system. Linux has had hundreds of vulnerabilities over the years; you seem to take offense at that, which is strange? I mean, the first step towards security is acknowledging you have vulnerabilities. The next step is securing them. You can't secure that which you are in denial about. Which in turn implies that you aren't actually interested in the security of your machine, hence the strangeness.> Try reading a book on Unix, almost everything runs on Linux these days > except for some silly widows computers in homes of people > who have not bought / borrowed / stolen / rented / learned / what else > have you a clue. >Windows, excuse me? Where did that come in? Oh, you must think I'm some sort of "fanboy" attacking your "camp" and so you must rush to its defense, spouting off every concievable deflection while continuing to ignore faults in your own system like being able to use punctuation in a random filename? Strange. Well, this part isn't strange at all, it's the same tribalism that's tearing the world apart right now, really. More sad than strange. :-\> Why do it to yerselves? > > And no this system is lemme see > ~ # uname -a > Linux panteltje12 2.6.37.6-smp #1 SMP Sat Aug 3 19:23:48 CEST 2013 i686 > AMD Sempron(tm) 145 Processor AuthenticAMD GNU/Linux > > Slackware, probably the most sane distro there is. > > Why bother updating? 'tworks right no?Ah, okay. So hopefully you've got most of these patched: https://www.cvedetails.com/vulnerability-list/vendor_id-27/product_id-41/Slackware-Slackware-Linux.html Waaait... 2.6? From 2011? But current version is 5.2.8 (stable)?! Then more specific I guess would be this, https://www.cvedetails.com/vulnerability-list.php?vendor_id=33&product_id=47&version_id=123871&page=1&hasexp=0&opdos=0&opec=0&opov=0&opcsrf=0&opgpriv=0&opsqli=0&opxss=0&opdirt=0&opmemc=0&ophttprs=0&opbyp=0&opfileinc=0&opginf=0&cvssscoremin=0&cvssscoremax=0&year=0&month=0&cweid=0&order=1&trc=214&sha=36e2264f1293f8fe45ef0e2c8ca35018397c6208 214 records. Not that all of those appear to be critical RCE exploits, or are necessarily in modules that you use regularly. I have no idea. But I mean, it's not zero, which is all the point I'm after. I must be misunderstanding something about Linux versioning or updating; surely it would be strange for someone to be questioning my (so far unstated) security practices, when they use a platform that hasn't been updated in the better part of a decade? And, like, it's entirely plausible that you've been watching those, and patching your own kernel (and applications) locally. That would be cool. But a big burden, and a big distraction from getting any work done. "Recompiling the kernel" seems to have always been a frequent refrain from the Linux community, which seems...bewildering to me? Do they expect average users to know how to do that? :(> Sure YOUR system may need updating because yet an other processor security > disaster was discovered last week. > https://thenextweb.com/security/2019/08/06/researchers-discover-troubling-new-security-flaw-in-all-modern-intel-processors/ > Not a day goes bye > > https://www.reuters.com/article/us-intel-cyber/new-intel-security-flaws-could-slow-some-chips-by-nearly-20-idUSKCN1SK2OD >Yeah, some crazy stuff going on these days. Not to mention the still present, and eminently hackable, Intel Management Engine hypervisor. Good thing AMD doesn't have a Platform Security Proces--oh.> I KNOW intel procesors are part of the NSA spy network. > That is why I keep the invasion plans carved in stone^H^H^H^H^HMDISC > hidden so they do not know the Orange House will be taken at noon. >Uh?...> That is why I run AMD so that sensitive data is not made public. > > U Use Intel I Presume?What? You again seem to be willing me into a side of a conflict I have no care for, or stake in. I don't appreciate it.> Huwei is releasing their own replacement for android shortly, thank Agent > Orange's tariffs > I may just get one, I do not like android, this can only get better, > Dunno if it is Linux based... > > <press power button to delete this text> > > UUGHPresumably Huwei will have "instrumentation" suitable for the Communist Party of China's purposes. Probably not active monitoring, but a fairly secure backdoor seems likely; the sort of thing our dear western leaders like to keep pushing. They may have /some/ sense about it, like a unique serial-numbered key per device, stored across isolated servers. I would expect typical services to be general unlock, pushing hidden apps / updates allowing targetted monitoring, etc. This would be, I think, rather plausible and rather less conspiracy-theoretic. Better them than us; but things would be so much nicer if We Could All Just Get Along(R). I guess we'll have to wait until Russia mass-pwns China's citizens to say "toldyaso" to them, and to our own leaders who keep pushing the same. An interesting thing, as security goes: for all their problems, Apple has been quite staunch in their rejection of such softening measures. Indeed the gov't was so frustrated they even sued about it (and lost). It's not often you see such a visible and explicit confirmation like that. The NSA is certainly getting their tentacles on everything they can. All the more reason to better review code, patch vulnerabilities as soon as they are found, and keep systems updated. Use crypto early and often, and responsibly. For the record -- my desktop reports "AMD Phenom(tm) II X6 1055T Processor" 2.8GHz, and runs a 64-bit OS that is supported (for now..) and up to date. So, not particularly new (about as old as yours, actually, and I think both predating AMD's PSP?). I don't care for specsmanship, I don't run anything that would benefit from more, and my graphics card mostly handles whatever is left to do. And for that matter, the newest games I've played, haven't even been 3D, what a waste it seems. Ah well. Incidentally, *this* client (XP, OE6) is LAN attached only, and basically just kept around for news only. Attackable definitely, but a limited surface. Tim -- Seven Transistor Labs, LLC Electrical Engineering Consultation and Design Website: https://www.seventransistorlabs.com/
Reply by ●August 10, 20192019-08-10
On 10/08/19 17:50, Tim Williams wrote:> "Tom Gardner" <spamjunk@blueyonder.co.uk> wrote in message > news:PFA3F.982900$j33.789547@fx26.am4... >> Nonetheless, an analytical solution to a /simplified/ model >> can yield valuable insights. The classic simplified model >> in physics is exemplified by "...assume a spherical cow...". >> >> There are many similar things in electronics, e.g. simple >> model are used to estimate EMI/EMC between one comms system >> and another. Imperfect? Of course; it never matches reality. >> Useful? Yes. > > Don't read into it too deeply.I don't :) Your other points with which I wholeheartedly agree...> The better lesson would be to work to your strengths, whatever they are; if they > are analytic, then work on that.� If not, work on faster methods of failing. > > Which, again, is no excuse to check ones' brain at the computer.� Problems can > always be done smarter. > > Limiting yourself to just one approach is the real problem.
Reply by ●August 10, 20192019-08-10
On a sunny day (Sat, 10 Aug 2019 12:55:55 -0500) it happened "Tim Williams" <tiwill@seventransistorlabs.com> wrote in <qin0f2$bk2$1@dont-email.me>:>For the record -- my desktop reports "AMD Phenom(tm) II X6 1055T Processor" >2.8GHz, and runs a 64-bit OS that is supported (for now..) and up to date. >So, not particularly new (about as old as yours, actually, and I think both >predating AMD's PSP?). I don't care for specsmanship, I don't run anything >that would benefit from more, and my graphics card mostly handles whatever >is left to do. And for that matter, the newest games I've played, haven't >even been 3D, what a waste it seems. Ah well. > >Incidentally, *this* client (XP, OE6) is LAN attached only, and basically >just kept around for news only. Attackable definitely, but a limited >surface. > >TimNa, I was not looking for a fight, thought you were. I have been running Linux since 1998 or so (Soft Landing Systems Linux it was called, found it on some CD that came with a magazine, and it replaced my win3.1 running on DRDOS with trumpet winsock. Before that internet we had Viditel here, more bulletin board oriented been 'online' since the eighties. As I ran Free agent newsreader on that win 3.1 and there was no look alike Usenet newsreader for Linux, I wrote NewsFleX (this one: http://panteltje.com/panteltje/newsflex/index.html still using it. So and also wrote most other apps that run here, except the web browser, that is a moving target and a life long work I have other interests. On top of that I am and always have been : root panteltje12: ~ # whoami root Ran my own servers back then until that became to much work now website is at godaddy. And godaddy has leased servers close to here in the Netherlands, so I am basically local with that website. Anyways tell me about the web, asked Hacktick to hack my servers, they tried, I watched and they failed. So, those were wilder years and lots of things were hacked.. Having Linux and gcc was and still is cool. But I have no illusions about security, WiF was hacked here so all is wired now. I tried (because of somebody advertising it here) win what was it? Xp ? once and it was removed really quick, new laptop came with some win version too, replaced it with Ubuntu the same day, now 4 different versions of Linux in different partitions on it. But this is my every day PC and very very hard to get into from the outside. Of course you should always use brain when using the browser... A very large part of the embedded world is running flavors of Linux, there are even satellites running it. Talk about reliability. ~ # uptime 20:48:39 up 79 days, 8:47, 15 users, load average: 2.35, 3.27, 3.78 Last reboot was 79 days ago, had to change some power cables? do not remember, For the rest I do not care who runs what, I wrote several OSes myself, some multitasker too. TCP stack for PIC, I can write what I want anytime in almost any language, except snake language 'python', NOTHING in all those years that I wrote has been hacked,. The hacked WiFi was a cheap Chinese security camera,, So, to make it easier for NSA I always explain my plans here, like the invasion of the US tomorrow (? or was it later) etc etc, and where I buy the plutonium and all that. You gotta help those guys, else they die of boredom. As you probably noticed I have not much to say about the subject, so I will leave it at this, Reply at your own risk, that goes for using closed source software too, also from ratmond.
Reply by ●August 10, 20192019-08-10
On Saturday, 10 August 2019 15:57:03 UTC+1, John Larkin wrote:> Circuit design starts with the topology problem: what is the schematic > that we want to analyze? Where does it come from? > > In my EE school, when I talked about designing things I was told > "Undergrads don't design; that starts in graduate school" so I didn't > apply for grad school.In fairness most undergrads don't design things. But if anyone wants to understand electronics at that age, they shoulda been designing things for years. Badly sometimes, how else does one learn. NT
Reply by ●August 10, 20192019-08-10
On Saturday, 10 August 2019 18:55:51 UTC+1, Tim Williams wrote:> An interesting thing, as security goes: for all their problems, Apple has > been quite staunch in their rejection of such softening measures. Indeed > the gov't was so frustrated they even sued about it (and lost). It's not > often you see such a visible and explicit confirmation like that. > > The NSA is certainly getting their tentacles on everything they can. All > the more reason to better review code, patch vulnerabilities as soon as they > are found, and keep systems updated. Use crypto early and often, and > responsibly.Was Apple's public stand for real, or was it showmanship when they complied behind closed doors? We'll probably never know. NT
Reply by ●August 10, 20192019-08-10
On Sat, 10 Aug 2019 15:59:51 +0100, Tom Gardner <spamjunk@blueyonder.co.uk> wrote:>On 10/08/19 15:56, John Larkin wrote: >> On Sat, 10 Aug 2019 15:38:39 +0100, Tom Gardner >> <spamjunk@blueyonder.co.uk> wrote: >> >>> On 10/08/19 14:47, John Larkin wrote: >>>> On Sat, 10 Aug 2019 08:11:49 +0100, Tom Gardner >>>> <spamjunk@blueyonder.co.uk> wrote: >>>> >>>>> On 10/08/19 01:55, Winfield Hill wrote: >>>>>> Plus, when you have an analytical >>>>>> solution to your circuit, you can more easily see >>>>>> what the trade offs are, and optimize the circuit. >>>>> >>>>> That should be writ large, and engraved in all >>>>> university courses. >>>>> >>>>> Unfortunately it is becoming a lost art :( >>>> >>>> Learning classic circuit theory and analysis is critical to doing >>>> original circuit design, but it's just the starting point. >>>> >>>> Design is the opposite of analysis. And most all the interesting stuff >>>> is seriously nonlinear. >>>> >>>> What the theory can do is provide insight, guide creative fiddling. >>>> Ultimately most of us solder parts to boards to make stuff that works, >>>> not publish papers. >>> >>> Completely understood and accepted. Anything significantly >>> non-linear virtually requires number crunching rather than >>> standard analysis. >>> >>> Nonetheless, an analytical solution to a /simplified/ model >>> can yield valuable insights. The classic simplified model >>> in physics is exemplified by "...assume a spherical cow...". >>> >>> There are many similar things in electronics, e.g. simple >>> model are used to estimate EMI/EMC between one comms system >>> and another. Imperfect? Of course; it never matches reality. >>> Useful? Yes. >> >> Circuit design starts with the topology problem: what is the schematic >> that we want to analyze? Where does it come from? >> >> In my EE school, when I talked about designing things I was told >> "Undergrads don't design; that starts in graduate school" so I didn't >> apply for grad school. > >Bizarre. Objectionable. My alma mater continues to have a >completely different tradition, 40 years later. They have >extremely well equipped labs, and the undergrads use them >at any time for any project, including personal projects.Well, the place was pretty fuddy-duddy. Most of the EEs went into power. -- John Larkin Highland Technology, Inc trk jlarkin att highlandtechnology dott com http://www.highlandtechnology.com
Reply by ●August 10, 20192019-08-10
