Let's Take A Vote...
in [Design]
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From: John Fields on 24 Jul 2010 16:27 On Sat, 24 Jul 2010 11:17:31 -0700 (PDT), Nunya <jack_shephard(a)cox.net> wrote: >On Jul 24, 9:49�am, John Fields <jfie...(a)austininstruments.com> wrote: >> On Sat, 24 Jul 2010 08:30:43 -0700, John Larkin>> --- >> More silly diversion... A red herring this time. >> >> http://www.youtube.com/watch?v=wNRH7_Kd5Yc >> >> JF > >I like your responses to lunacy being in the form of >song references. That is pretty cool and fun to try >to track the "What do you mean by that?" function. > tee hee hee :-) --- :-)
From: Jim Thompson on 24 Jul 2010 16:32 On Sat, 24 Jul 2010 16:11:18 -0400, Phil Hobbs <pcdhSpamMeSenseless(a)electrooptical.net> wrote: >On 7/24/2010 3:53 PM, Jim Thompson wrote: >> On Sat, 24 Jul 2010 15:19:00 -0400, Phil Hobbs >> <pcdhSpamMeSenseless(a)electrooptical.net> wrote: >> >>> Jim Thompson wrote: >>>> On Sat, 24 Jul 2010 15:09:38 -0400, Phil Hobbs >>>> <pcdhSpamMeSenseless(a)electrooptical.net> wrote: >>>> >>>>> Jim Thompson wrote: >>>>>> On Sat, 24 Jul 2010 14:38:53 -0400, Phil Hobbs >>>>>> <pcdhSpamMeSenseless(a)electrooptical.net> wrote: >>>>>> >>>>>>> John Fields wrote: >>>>>>>> On Fri, 23 Jul 2010 15:52:06 -0700, Jim Thompson >>>>>>>> <To-Email-Use-The-Envelope-Icon(a)On-My-Web-Site.com> wrote: >>>>>>>> >>>>>>>>> Let's Take A Vote... >>>>>>>>> >>>>>>>>> While I write this up, hopefully sometime this weekend, let me ask for >>>>>>>>> votes... >>>>>>>>> >>>>>>>>> How many think, as Larkin opines, "charge is not conserved" ?? >>>>>>>>> >>>>>>>>> How many think charge IS conserved ?? >>>>>>>>> >>>>>>>>> Just curious what I'm up against here. >>>>>>> http://www.cafepress.com/dd/1478200 >>>>>>> >>>>>>> Cheers >>>>>>> >>>>>>> Phil Hobbs >>>>>> Of course. Child molestation exists in Catholic land ONLY if you get >>>>>> caught. >>>>>> >>>>>> ...Jim Thompson >>>>> As I said to Vlad the other day, where I come from we know a trick worth >>>>> two of that one. You can get more integrated current out of a >>>>> transformer than you put in, too. So what? >>>>> >>>>> Cheers >>>>> >>>>> Phil Hobbs >>>> >>>> Yep. Must be black magic :-) >>>> >>>> ...Jim Thompson >>> >>> Every step-down DC-DC converter in the world puts out more current than >>> it takes in, as commonly understood in the EE world. Or does your PC >>> have a mondo heatsink on the PSU? >>> >>> Cheers >>> >>> Phil Hobbs >> >> Of course it does (*). I was being facetious. How did you miss it >> ?:-) >> >> (*) Thus my tongue-in-cheek post... >> >> "NNTP-Posting-Date: Tue, 20 Jul 2010 10:24:26 -0500 >> From: Jim Thompson<To-Email-Use-The-Envelope-Icon(a)On-My-Web-Site.com> >> Newsgroups: sci.electronics.design >> Subject: Charge Conservation - Hint of the Day >> Date: Tue, 20 Jul 2010 08:24:26 -0700 >> Message-ID:<jqfb469iggbg6dkeu84c8kgp3m9g0alr3m(a)4ax.com> >> >> Charge Conservation - Hint of the Day: >> >> How many Coulombs can a 1mH inductor charged to 1A deliver?" >> >> Which seems to have gone over everyone's head and created asinine >> retorts. >> >> Such a "discussion" group... NOT :-( >> >> Nothing but a bunch of prima donnas and bloviators. >> >> ...Jim Thompson > >I'm terribly sorry about that. Some things are easy to miss in your >recent posts, though--actual engineering content, for instance, as >opposed to organic waste material. I'm reminded of the famous book >review by Moses Hadas: "This book fills a much-needed space." ;) > >You claim merely to want to correct error and set the record >straight--so why all the junior high school coyness and posturing, >rather than just posting a link? Maybe we could all learn something >useful. > >I've used many of your chips with both profit and pleasure (I used to >love the MC1648, for instance), and so have most of the rest of us on >SED, so you really don't need to do this to gain respect. > >Cheers > >Phil Hobbs I err in trying to taunt youngsters (can't use "young bucks" anymore, John "The Bloviator" Larkin gets sexually aroused :) to think for themselves. That's the way you really learn, not by having answers served up to you on a platter. I owe my inquisitiveness and tenacity to one old battle-axe of an 8th grade Algebra teacher, Evelyn Truchovesky, who forced me to think things through on my own. She impressed me so much that I, to this day, use her way of writing a capital "E" for my middle initial. And then there was a Trigonometry teacher who kept me away by handing me textbook after textbook, "Here! Work all the problems in this book, THEN come discuss them with me." :-) Glad you like the MC1648! Still popular, but no one making it anymore. Last year I did a custom chip design that, amongst a gezillion other functions, featured two MC1648 equivalents, but on a faster process and with significantly improved AGC. ...Jim Thompson -- | James E.Thompson, CTO | mens | | Analog Innovations, Inc. | et | | Analog/Mixed-Signal ASIC's and Discrete Systems | manus | | Phoenix, Arizona 85048 Skype: Contacts Only | | | Voice:(480)460-2350 Fax: Available upon request | Brass Rat | | E-mail Icon at http://www.analog-innovations.com | 1962 | Spice is like a sports car... Only as good as the person behind the wheel.
From: John Larkin on 24 Jul 2010 16:38 On Sat, 24 Jul 2010 15:14:41 -0400, Phil Hobbs <pcdhSpamMeSenseless(a)electrooptical.net> wrote: >Grant wrote: >> On Sat, 24 Jul 2010 08:51:58 -0700, John Larkin <jjlarkin(a)highNOTlandTHIStechnologyPART.com> wrote: >> >>> On Sat, 24 Jul 2010 09:45:53 +0100, Martin Brown >>> <|||newspam|||@nezumi.demon.co.uk> wrote: >>> >>>> On 23/07/2010 23:52, Jim Thompson wrote: >>>>> Let's Take A Vote... >>>>> >>>>> While I write this up, hopefully sometime this weekend, let me ask for >>>>> votes... >>>>> >>>>> How many think, as Larkin opines, "charge is not conserved" ?? >>>> Hopefully not too many. But it is difficult to predict the behaviour of >>>> electronics engineers - about half of them think Einstein was wrong :( >>>>> How many think charge IS conserved ?? >>>> Just about every physicist on the planet since Ben Franklin. >>>> >>>> It was the inconsistency of Ampere's Law with conservation of charge >>>> that led Maxwell to formulate his famous equations and show that >>>> oscillating fields of electromagnetic radiation travel at a constant >>>> speed c in a vacuum. >>>>> Just curious what I'm up against here. >>>>> >>>>> ...Jim Thompson >>>> A idealised physics version of your original capacitor problem but >>>> without the switch can be stated as the following problem: >>>> >>>> Two identical metal spheres with capacitance C are used. >>>> Initially one is uncharged and the other with a charge Q >>>> >>>> They are brought together from infinity until they touch. >>>> >>>> Describe what happens and how the charge is distributed after they are >>>> in electrical contact. You can add an infinite ground plane under the >>>> experiment if it makes you feel better about the circuit analogue. >>>> >>> Where can I buy 0.33 uF surface-mount metal spheres? Are they >>> expensive? I'd need ROHS, of course, on reels. [1] >> >> Second terminal optional?! >> >> But then, we sorta cater to 'monopole' charge when using human >> body model's charge for anti-static measures. >> >> Grant. >>> John >>> >>> [1] extra credit: how big would they be? >>> > >Objects have both self-capacitance and mutual capacitance, so it's quite >sensible to talk about a capacitor with only one lead. In Gaussian >units, the self-capacitance of an isolated sphere of radius r >centimetres is r. (The CGS unit of capacitance is the centimetre.) > >One cm ~= 1.12 pF, so 330,000 pF is about 30 km radius. That's quite a >big reel! > >Cheers > >Phil Hobbs The entire planet is only about a 700 uF cap, but the voltage rating is pretty good. Bob Pease presided over a debate a few years ago about the capacitance between the earth and the moon; there were two distinct values cited, and he came down on the side of the smaller one and ridiculed the other. I think it depends on whether you do a 2-terminal or a 3-terminal measurement. One equation approaches zero C with distance, the other levels off. I wonder what the net voltage of "ground" is. Since we keep getting whacked with solar wind (net protons?) we might actually be heavily charged. There's a considerable gradient at the surface. John
From: John Fields on 24 Jul 2010 16:46 On Sat, 24 Jul 2010 11:24:55 -0700, John Larkin <jjlarkin(a)highNOTlandTHIStechnologyPART.com> wrote: >Force is measured in newtons. Look it up. --- As is the _mechanical_ force exerted by an electrical charge. For example, in the post I made from Schaum's, you obviously missed supplemental problem 24 on page 144: Q. "If two equal charges, each of 1 coulomb, were separated in air by a distance of 1km, what would be the force between them?" A. "9000 nt repulsion." --- >Now we have claims that coulombs, volts, and abvolts are all measures >of force. Any other contributions? Can you measure force in >milliseconds, or in henries? Do any units mean anything at all? --- Well, by restating the problem like this: "What two like charges, separated in air by a distance of 1km would cause a repulsive force between them of 9000 nt?" ,it becomes obvious that charge can be a measure of mechanical force since the answer is: "One coulomb each." As for volts and abvolts, I don't believe there's any question that those are units of _electromotive_ force, do you?
From: John Larkin on 24 Jul 2010 16:48
On Sat, 24 Jul 2010 15:23:53 -0500, John Fields <jfields(a)austininstruments.com> wrote: >On Sat, 24 Jul 2010 10:32:36 -0700, John Larkin ><jjlarkin(a)highNOTlandTHIStechnologyPART.com> wrote: > >>On Sat, 24 Jul 2010 12:25:15 -0500, John Fields >><jfields(a)austininstruments.com> wrote: >> >>>On Sat, 24 Jul 2010 10:13:48 -0700, John Larkin >>><jjlarkin(a)highNOTlandTHIStechnologyPART.com> wrote: >>> >>>>On Sat, 24 Jul 2010 11:49:38 -0500, John Fields >>>><jfields(a)austininstruments.com> wrote: >>>> >>>>>On Sat, 24 Jul 2010 08:30:43 -0700, John Larkin >>>>><jjlarkin(a)highNOTlandTHIStechnologyPART.com> wrote: >>>>> >>>>>>On Sat, 24 Jul 2010 09:04:41 -0500, John Fields >>>>>><jfields(a)austininstruments.com> wrote: >>>>>> >>>>>>>On Sat, 24 Jul 2010 08:15:03 -0500, John Fields >>>>>>><jfields(a)austininstruments.com> wrote: >>>>>>>On F>> >>>>>>>>On Fri, 23 Jul 2010 17:38:45 -0700, John Larkin >>>>>>>><jjlarkin(a)highNOTlandTHIStechnologyPART.com> wrote: >>>>> >>>>> >>>>>>>>>Charge is measured in coulombs. Force is measured in newtons. So how >>>>>>>>>is charge "a measure of force"? >>>>>>>> >>>>>>>>--- >>>>>>>>news:2apl46hr8s01os8dv1aipdm19bcf64nec4(a)4ax.com >>>>>>> >>>>>>>--- >>>>>>>Oh, and the first sentence of the cited Wikipedia article reads: >>>>>>> >>>>>>>"Electric charge is a physical property of matter which causes it >>>>>>>to experience a force when near other electrically charged matter." >>>>>>> >>>>>>> >>>>>>>JF >>>>>> >>>>>>If you experience a pig, does that make you a pig? >>>>> >>>>>--- >>>>>That's just a silly diversionary tactic; measuring a force doesn't >>>>>make you the force. >>>>>--- >>>>> >>>>>>Look at the SI units if you want to determine if things are the same. >>>>> >>>>>--- >>>>>That's just another silly diversionary tactic. >>>> >>>>Were you ever taught dimensional analysis? >>>> >>>>Obviously not. Give it a try: >>>> >>>>http://en.wikipedia.org/wiki/Dimensional_analysis >>>> >>>>The basic concept is that you can test all sorts of relationships for >>>>plausibility by reducing their SI units. If the units don't agree, the >>>>things can't be equal. Newtons aren't coulombs, so charge can't be >>>>force. >>> >>>--- >>>No one said it was. >> >> >>You did: >> >>>>On the other hand, if Larkin's right and energy is conserved but >>>>charge isn't, then since charge is a measure of force, unbalanced lost >>>>charge might be able to be used for propulsion. > >--- >Ah, now I see. > >You can't tell the difference between: "charge is force" and: "charge >is a measure of force." > >JF You might read this http://en.wikipedia.org/wiki/Dimensional_analysis#Commensurability since it's the easiest part of the article to understand. Engineers do sometimes break the rules and add non-commensurable units, like designing a foldback power supply that limits the sum of a voltage and a current. Addition is a poor substitute for multiplication, but it's a lot easier to do with cheap parts. John |