Peter T. Daniels ran out of electrical outlets; states rewiring entire house to be the only feasible solution.
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From: PaulJK on 29 Mar 2010 00:46 Peter Duncanson (BrE) wrote: > On Sun, 28 Mar 2010 18:15:53 +1200, "PaulJK" > <paul.kriha(a)paradise.net.nz> wrote: > >> Hatunen wrote: >>> On Sat, 27 Mar 2010 09:29:58 +0000, Mike Barnes >>> <mikebarnes(a)bluebottle.com> wrote: >>> >>>> Hatunen <hatunen(a)cox.net>: >>>>> On Fri, 26 Mar 2010 08:06:21 +0000, Jonathan de Boyne Pollard >>>>> <J.deBoynePollard-newsgroups(a)NTLWorld.COM> wrote: >>>>>> [...] >>>>>> energy being delivered, the amount of which is >>>>>> determined by the wattage, >>>>> >>>>> I suppose one might casually say that, but in fact the power >>>>> (wattage) is a function of the current and resistance, not >>>>> vise-versa. >>>> >>>> How so? >>> >>> Power is a result of passing a current through a resistance; >>> current and rsistance aren't a result of power. >> >> It could be also said that >> the current is a result of applying voltage to a resistance. >> :-) > > That is one way of creating a current. Another is with a varying > magnetic field as in generators and in the secondary windings of > transformers. The usual equations describing the phenomena, treat the effect of EMF as creating voltage gradient which may or may not result in electric current. Take for example your secondary windings of a transformer. If the secondary winding has no load connected to it, the voltage is still generated but results in no current. The same can be said about voltages generated by light, heat, nuclear radiations, etc. First you have to create an inbalance in the numbers of free electrons and/or holes between two places before the current can take place along the interconnecting conductor, if there is one. pjk P.S. You may argue that moving electrons or holes from one end of the open loop winding of your transformer to the other can be viewed as current, but I assume that that was not the kind of current you had in mind.
From: PaulJK on 29 Mar 2010 00:55 Doctroid wrote: > In article <homphq$91l$1(a)news.eternal-september.org>, > "PaulJK" <paul.kriha(a)paradise.net.nz> wrote: > >> Voltage and current are proportional to each other. >> It is therefore sufficient to say that damage is proportional >> to one of them. > > Only in materials and voltage/current ranges where Ohm's "law" is > obeyed. And if damage is occurring, it probably isn't. Ohm's law is always obeyed in all aparatus made by humans. pjk
From: PaulJK on 29 Mar 2010 01:19 Doctroid wrote: > In article <28cvq5thba4ntr25kfgdnlk07lvha4ftd5(a)4ax.com>, > Glenn Knickerbocker <NotR(a)bestweb.net> wrote: > >> On Sun, 28 Mar 2010 18:42:14 +0100, Jonathan de Boyne Pollard wrote: >>>> Voltage and current are proportional to each other. It is therefore >>>> sufficient to say that damage is proportional to one of them. >> >> Well, one of them squared. >> >>> Wrong, as already explained. You're missing out a fair number of >>> dimensions. You make my point to M. Knickerbocker for me. You are >>> definitely trying to argue that voltage alone is sufficient, >> >> He argued nothing of the sort. He described how the effect varies with >> voltage (or current, or power), independently of the other factors. > > Another words, he was trying to convey the essential idea underlying > partial derivatives: finding how a function of many variables changes > when one variable changes and the others are held fixed. Yes, that is a good characterisation of the idea. Practical empirical example can go something like this: I put one dry finger of one of my hands on 120V 50Hz AC phase conductor and a second dry finger on an earthed conductor. It buzzes and if I am not taken by surprise, I don't have to break the connection. I do the same with 240V and it stings, the muscles in my hand and arm involuntarily contract even if I expect the shock but I can still avoid hitting other instruments on the desk. When I got zapped from a 500V secondary winding of a vacuum valve radio, my hand hurt for days afterwards even though the contact was presumably shorter than about 80ms. Of course the physiological reaction to electric shock can have quite complex relationship with voltage but it seems to be is at least 2nd degree exponentialy related. pjk
From: David DeLaney on 28 Mar 2010 20:15 PaulJK <paul.kriha(a)paradise.net.nz> wrote: >Jonathan de Boyne Pollard wrote: >> Actually, you never wrote any such thing. But you did write what's >> quoted above. > >I say it again: I wrote words to that effect at the beginning >of the subthread. You have zapped it a long time ago >and of course you don't remember you did. ....so ... should he have been posting with one hand in his pocket? Dave "and would the experience have taught him anything?" DeLaney -- \/David DeLaney posting from dbd(a)vic.com "It's not the pot that grows the flower It's not the clock that slows the hour The definition's plain for anyone to see Love is all it takes to make a family" - R&P. VISUALIZE HAPPYNET VRbeable<BLINK> http://www.vic.com/~dbd/ - net.legends FAQ & Magic / I WUV you in all CAPS! --K.
From: David DeLaney on 28 Mar 2010 20:18
PaulJK <paul.kriha(a)paradise.net.nz> wrote: >Doctroid wrote: >> "PaulJK" <paul.kriha(a)paradise.net.nz> wrote: >>> Voltage and current are proportional to each other. >>> It is therefore sufficient to say that damage is proportional >>> to one of them. >> >> Only in materials and voltage/current ranges where Ohm's "law" is >> obeyed. And if damage is occurring, it probably isn't. > >Ohm's law is always obeyed in all aparatus made by humans. .... ... Okay, so you're not an engineer AND are not an experimentalist. Meaning you're a theorist. This explains some things. (Tell the court, please, how long ago it was that humans made the first material that had exactly the same resistance at every interior point, and how to get current to go through an object in such a way as to have the same current density everywhere inside the object...) Dave -- \/David DeLaney posting from dbd(a)vic.com "It's not the pot that grows the flower It's not the clock that slows the hour The definition's plain for anyone to see Love is all it takes to make a family" - R&P. VISUALIZE HAPPYNET VRbeable<BLINK> http://www.vic.com/~dbd/ - net.legends FAQ & Magic / I WUV you in all CAPS! --K. |