haynes@ucscc.UCSC.EDU.ucsc.edu (99700000) (11/04/87)
The new issue of Technology Review (M.I.T. magazine) has an article on this subject. I haven't had time to read it yet. haynes@ucscc.ucsc.edu haynes@ucscc.bitnet ..ucbvax!ucscc!haynes
robert@uop.UUCP (Robert McCaul) (11/05/87)
you could do what a buddy of mine did...
(his barn was overshot by high voltage lines)
wrap the rafters with coils, and make off with some free power!!
his barn had "infinite" lighting this way!!!
no foolin'
"When freedom is outlawed, only outlaws will have freedom"
...princeton!rutgers!retix!\
robert@ucdavis.arpa ...sun!ptsfa!cogent! uop!robert
...uwvax!ucbvax!ucdavis!/
...mcvax!uunet!mit-eddie!garp!ames!/die@frog.UUCP (Dave Emery) (11/07/87)
In article <688@uop.UUCP> robert@uop.UUCP (Robert McCaul) writes: > >you could do what a buddy of mine did... > >(his barn was overshot by high voltage lines) > >wrap the rafters with coils, and make off with some free power!! > >his barn had "infinite" lighting this way!!! > I imagine he had to have some sort of voltage regulator as the induced EMF in his attic coils would vary with the currents flowing through the power lines near his barn. Since there were probably several phases and even different circuits on the wires over his barn with differing degrees of coupling to his pickoff coils, the actual voltage he observed was no doubt not a function of the current on any one wire but of several. I should think the current flowing through a cross country power line would change considerably as demand in the places it served varied. I suppose that regional power pools must control the currents on intertie lines within limits but don't certainly keep them constant. Does anybody know better ? I have heard a similar story about farmers in the Midwest using long stretches of barbed wire fence near long distance power lines for the same "free" power gambit. As I understand it the power companies were able to sucessfully prosecute some of them for stealing power. David I. Emery Charles River Data Systems 617-626-1102 983 Concord St., Framingham, MA 01701. uucp: decvax!frog!die
larry@kitty.UUCP (Larry Lippman) (11/07/87)
In article <1913@frog.UUCP>, die@frog.UUCP (Dave Emery) writes: > >you could do what a buddy of mine did... > >(his barn was overshot by high voltage lines) > >wrap the rafters with coils, and make off with some free power!! > >his barn had "infinite" lighting this way!!! One minor point: no way, EVER will an electric utility company run power lines OVER a customer structure (the liability factors and other reasons for this should be obvious). > I have heard a similar story about farmers in the Midwest using > long stretches of barbed wire fence near long distance power lines for the > same "free" power gambit. As I understand it the power companies were able > to sucessfully prosecute some of them for stealing power. The above situations sound like rural (as opposed to urban) legends to me. I suppose if I keep this up, someone is going to confer upon me the title of "Net Skeptic"... :-) [This remark, which I couldn't help, makes more sense if you have been following my postings in another newsgroup, which shall remain unnamed :-).] Now, let's look at this situation and apply a bit of electrical engineering. Let's assume the following: 1. There is a high-voltage electrical transmission line operating at 128 to 356 kV; the actual voltage is immaterial since all we care about is current flow. A typical single conductor current for such a transmission line using 1200 MCM ACSR conductor is 1,000 amperes (somewhat on the high side). 2. There is a distance of 40 feet from the power conductor to a "receiving coil"; this figure is pretty conservative, since under most circumstances, I don't believe it is possible to get that close. Since this amounts to a one-turn primary, the flux density (B) 40 feet away will be given by: B = (4.52)(I)/(h), where B is flux density in lines/sq inch, I is current in amperes, and (h) is "air gap" distance in inches. Plugging in 1,000 amperes and 40 feet makes B = 9.4 lines/sq in (1.5 Gauss for you Gauss fans). As a point of comparison, this magnetic field is roughly 3 times that of the earth's natural magnetic field. Now, let's make the following assumptions about a "receiving coil": 1. The coil is rectangular, 40 feet long and 4 feet wide, and optimally oriented below the transmission line conductor. 2. There is an iron "core" (pretty damn big piece of metal!); the resultant value below will be more than for an air core. Let's see what open-circuit sinusoidal voltage will appear in ONE turn of the above "receiving coil". E = (4.44x10^-8)(a)(B)(f)(N), where E is induced voltage, a is cross-sectional area of core, B is peak flux density in lines/sq in, f is frequency in Hertz, and N is number of turns (1 for now). Plugging in 9.4 lines/sq in of flux density and the area of the example "receiving coil" gives us an induced voltage of 0.58 volts per turn of receiving coil. Since 1/2 volt won't be very useful, we will need 120/0.58 = 206 turns to give us 120 volts. Let's use # 12 AWG wire. (206 turns)(40 ft + 40 ft + 4 ft + 4 ft) = 18,128 feet. Hmmm... That's OVER THREE MILES of wire to give us 120 volts. Let's see how much power we can derive: 18,128 feet of # 12 AWG wire gives us a DC resistance of 30 ohms, which means that by virtue of DC resistance alone, we will be limited to a power transfer of roughly 240 watts (assuming load impedance = source impedance). The power transfer will really be less, but I don't feel like doing the AC-side calculations to provide an exact figure. The above assumes an iron core in the "receiving coil", which at 4 x 40 feet in dimensions is pretty impracticable. Without actually doing the calculations, an air core would be at least an order of magnitude less efficient. Of course, we do have THREE conductors, each of which contributes to the magnetic field. On the other hand, no way will there be a 40 foot air gap between each conductor and the receiving coil. At BEST, with over 3 miles of # 12 AWG wire one may get enough free energy to light a 40-watt light bulb. Hardly seems worth the effort... At a cost of around $ 1,000.00 for the copper wire alone, I doubt that anyone has really tried it. [P.S. to Ed Hall: I will not be offended if you view this article with "suspicion" and doubt.] <> Larry Lippman @ Recognition Research Corp., Clarence, New York <> UUCP: {allegra|ames|boulder|decvax|rutgers|watmath}!sunybcs!kitty!larry <> VOICE: 716/688-1231 {hplabs|ihnp4|mtune|seismo|utzoo}!/ <> FAX: 716/741-9635 {G1,G2,G3 modes} "Have you hugged your cat tor,, but
robert@uop.EDU (Robert McCaul--The Equalizer) (11/08/87)
the barn was free standing, the farmer had loads of wire in the attic of said barn, and the bulbs were on all the time... this is a cousin of a family i used to live with, and so i would not think he would have any reason to lie to me about what he saw at his cousin's house yes it was in a very rural setting.
rwa@auvax.UUCP (11/09/87)
Mr Lippmann provides us with an erudite and convincing (to me, anyway) rationale which leads one to view claims of free power via m-field coupling with suspicion. Fine. Could someone, anyone, tell me why the E-field couldn't be used instead? Obviously the impedances would be pretty amazingly high; but that's what #40 magnet wire's all about ;-) By the way, I have _absolutely_ no idea as to the practicality of this suggestion, either. Ross Alexander @ Athabasca U.
roger@telesoft.UUCP (Roger Arnold @prodigal) (11/10/87)
In article <2209@kitty.UUCP>, larry@kitty.UUCP (Larry Lippman) writes: > In article <1913@frog.UUCP>, die@frog.UUCP (Dave Emery) writes: > > > I have heard a similar story about farmers in the Midwest using > > long stretches of barbed wire fence near long distance power lines for the > > same "free" power gambit. As I understand it the power companies were able > > to sucessfully prosecute some of them for stealing power. > > The above situations sound like rural (as opposed to urban) legends > to me. [..] > Now, let's look at this situation and apply a bit of electrical > engineering. Let's assume the following: > > [back-of-envelope analysis omitted] > The above assumes an iron core in the "receiving coil", which at > 4 x 40 feet in dimensions is pretty impracticable. Without actually doing > the calculations, an air core would be at least an order of magnitude less > efficient. > <> Larry Lippman @ Recognition Research Corp., Clarence, New York > <> UUCP: {allegra|ames|boulder|decvax|rutgers|watmath}!sunybcs!kitty!larry > <> VOICE: 716/688-1231 {hplabs|ihnp4|mtune|seismo|utzoo}!/ > <> FAX: 716/741-9635 {G1,G2,G3 modes} "Have you hugged your cat today?" I'm probably sticking my foot in my mouth, since I haven't really thought about the problem, and Larry isn't often wrong. However.. I don't immediately see what iron core vs. air core has to with the amount of power that can be extracted in this situation. There's a certain induced EMF in the pickup loop, and the power extracted is a function of the integral of the product of this EMF and the current in the pickup loop over one cycle. If you assume a simple resistive load in the pickup loop, then you get one answer. But if you were serious about extracting power by this method, wouldn't you use a resonant circuit, or something that gave a high current in the pickup coil, properly phased against the induced EMF? Hmm, the process is still limited by resistive losses in the pickup loop. Doesn't do any good to push more current through to extract more power, if the increased resistive losses more than offset the additional power extracted. Probably optimizes out to about what Larry calculated... unless, of course, what you're INTERESTED in is heating the barn. Well, back to the drawing board. :-] - Roger Arnold ..sdcsvax!telesoft!roger
john@hpcvla.HP.COM (John Eaton) (11/10/87)
I have heard a similar story about farmers in the Midwest using long stretches of barbed wire fence near long distance power lines for the same "free" power gambit. As I understand it the power companies were able to sucessfully prosecute some of them for stealing power. ------------------------------------- This is true!!! You can see these fences all over the midwest. They are easy to spot because they all have to use insulators to hold up the wire. Sometimes they will run the wire back to the farmhouse while other times they will use a device called an "electric fence charger" to take the stolen power from the fence and charge a storage battery. If you don't think you can get a lot of power from these then you just try grabbing hold of one and see if it doesn't knock you for a loop. :) :) :) John Eaton !hplabs!hp-pcd!john
larry@kitty.UUCP (Larry Lippman) (11/11/87)
In article <112@telesoft.UUCP>, roger@telesoft.UUCP (Roger Arnold @prodigal) writes: > > > I have heard a similar story about farmers in the Midwest using > > > long stretches of barbed wire fence near long distance power lines for the > > > same "free" power gambit. > > > > The above situations sound like rural (as opposed to urban) legends > > to me. [..] > > Now, let's look at this situation and apply a bit of electrical > > engineering. > > [back-of-envelope analysis omitted] > > The above assumes an iron core in the "receiving coil", which at > > 4 x 40 feet in dimensions is pretty impracticable. Without actually doing > > the calculations, an air core would be at least an order of magnitude less > > efficient. > I don't immediately see what iron core vs. air core has to with the amount > of power that can be extracted in this situation. Hmmm... You pose a good question! I will try to answer it as best I can. The first issue to be decided is what mathematical/physical model to use for explanations and calculations. As I see it, we have no choice but to consider this as a "transformer" situation, and we have at least two models to choose from: 1. We can use an "iron core" transformer model, with the power line as a single-turn primary, and an "air gap" (damn big one! :-) between the primary and secondary windings. This model is the one that I used because it was the most simple, and I know the equations from memory. While the "air gap" is admittedly large, the results still seem reasonable to me. 2. We can use an "air core" transformer model. Since we don't exactly have tight-coupled (i.e., bifilar) windings that have a relatively simple solution, the only method available is to use the mutual inductance method. This is much more complex than the "iron core" calculations above. It's been a while since I have done an air core transformer calculation by the mutual inductance method, but I believe it is essential that an incremental length of power line be chosen, along with a calculated voltage differential and inductance of such incremental length; this is starting to get esoteric and complex since we now have to speculate on power line characteristics beyond that of current flow. So my first point is: I chose an iron core because it was required for the calculation which I used. In general, the following are reasons why an iron core should RESULT in greater efficiency than an air core in this, uh, application: 1. The general objective of ferromagnetic cores is to confine the magnetic flux within the transformer windings. An iron core has a much lower reluctance than an air core; therefore less primary current is required to establish a given magnetic flux in an iron core than in an air core. In addition, when current flows through the secondary winding of a transformer, a secondary flux is created, and the presence of the iron core confines this secondary flux and thereby minimizes the transformation loss. 2. Consider the self-inductance of the "transformer" windings. The emf of self-inductance is (L)di/dt. The self-inductance is obviously much larger with an iron core, and therefore di/dt need not be as large to produce a given emf. 3. Consider that an iron core extending beyond the "secondary" winding will capture and direct more lines of flux to the winding itself. Consider also that the presence of such an iron core will make "alignment" of the "secondary" winding with respect to the "primary" winding less critical for optimum power transfer. > But if you were serious about extracting power by > this method, wouldn't you use a resonant circuit, or something that gave a > high current in the pickup coil, properly phased against the induced EMF? Creating a resonant secondary circuit only has the effect of making secondary impedance approach Rs at the point of resonance. The secondary impedance is probably not going to be much greater than Rs anyhow, so the use of a resonant circuit may be of marginal benefit. Also, a problem develops in that as the impedance of the "load" on the tuned secondary winding changes, so does the resonance of the secondary winding; as a result, this arrangement would have to be retuned each time the load changes - which is not such a great idea. I don't want to talk about the polyphase implications of three "primary" windings with one "secondary" winding in this application. :-) <> Larry Lippman @ Recognition Research Corp., Clarence, New York <> UUCP: {allegra|ames|boulder|decvax|rutgers|watmath}!sunybcs!kitty!larry <> VOICE: 716/688-1231 {hplabs|ihnp4|mtune|utzoo|uunet}!/ <> FAX: 716/741-9635 {G1,G2,G3 modes} "Have you hugged
larry@kitty.UUCP (Larry Lippman) (11/12/87)
In article <390@auvax.UUCP>, rwa@auvax.UUCP (Ross Alexander) writes: > Mr Lippmann provides us with an erudite and convincing (to me, anyway) > rationale which leads one to view claims of free power via m-field > coupling with suspicion. Fine. Could someone, anyone, tell me why the > E-field couldn't be used instead? Obviously the impedances would be > pretty amazingly high; but that's what #40 magnet wire's all about ;-) I was afraid that someone would ask that question... Consider the following: To tap the, uh, E-field we run a parallel "pickup" wire for 1,000 feet in close proximity to the power lines, with this wire having a diameter of 1 inch and being supported on poles with insulators. We will assume a separation of 40 feet between the wire and one power line conductor, and 40 feet between the wire and the ground. Using a common formula for power line engineering, this results in a capacitance of 0.0014 microfarads between the pickup wire and the power line conductor; considering the reactance to be purely capacitive (not really true, but close enough for now), we have an impedance between the pickup wire and the power line conductor of around 1,890,000 ohms. Assuming a power line voltage of 365 kV, and since the capacitance between the pickup wire and the power line is roughly equal to capacitance between the pickup wire and ground, we have a voltage divider and therefore have around 183 kV on the pickup wire. Using the above 183 kV and 1,890,000 ohm impedance, we would have a maximum current flow of roughly 0.097 ampere. If we could somehow directly utilize the 183 kV, we would have 18 kva of "free energy". Not bad; that is more than enough energy to power a small house. However, in order to get at this "free energy", we will need a transformer with a 183 kV primary - neither cheap nor simple - nor a particularly safe do-it-yourself project. Actually, the 1,000 feet of pickup wire 40 feet in the air on poles with huge insulators may make the power company suspicious, although there is probably not much they can do about it. :-) > By the way, I have _absolutely_ no idea as to the practicality of this > suggestion, either. See above. :-) Actually, there is a useful point that is illustrated by the above example. Unenergized wires that are also ungrounded and run in close proximity to high voltage power lines can pose a serious danger of electrical shock as they would acquire a high potential due to capacitive effect. This is why utility company craftspersons working on unenergized lines in close proximity to energized lines always ground both ends of the line, or treat the unenergized line as if it were energized. More than one utility company employee has been electrocuted through touching an unconnected, but ungrounded wire running parallel to energized circuits. <> Larry Lippman @ Recognition Research Corp., Clarence, New York <> UUCP: {allegra|ames|boulder|decvax|rutgers|watmath}!sunybcs!kitty!larry <> VOICE: 716/688-1231 {hplabs|ihnp4|mtune|utzoo|uunet}!/ <> FAX: 716/741-9635 {G1,G2,G3 modes} "Have you hugged your cat today?"
eichin@athena.mit.edu (Mark W. Eichin) (11/12/87)
I suspect it would be electric, not magnetic field effects that matter, mainly from the propaganda stuff I have seen with people walking under high-tension lines holding Flourescent tubes and having them glow... someone want to work out that math? Mark Eichin <eichin@athena.mit.edu>
larry@kitty.UUCP (Larry Lippman) (11/12/87)
In article <1788@bloom-beacon.MIT.EDU>, eichin@athena.mit.edu (Mark W. Eichin) writes: > I suspect it would be electric, not magnetic field effects that > matter, mainly from the propaganda stuff I have seen with people > walking under high-tension lines holding Flourescent tubes and having > them glow... It only takes a few microamperes of current at several hundred volts to ionize the gas in a fluorescent lamp. If you held one end of the lamp in one hand, while pointing the other end upward toward the power line - you may well have a sufficient potential difference to ionize the gas - provided you can get close enough, and provided there is enough voltage (lower voltage lines like 4.16 kV won't create enough of a field close to the ground). The lamp won't be bright enough to be really useful, however. If you recall my recent article on the power line E-field, the _potential_ is there, but the effective impedance will be much to high to get any useful current flow unless you increase the length and cross- sectional area of the pickup wire to a significant amount (as in my 1,000 foot wire example). Also, in simple terms, the pickup wire functions as a voltage divider when the distance between it and the power line, and the earth is considered. > someone want to work out that math? Thanks, but no thanks. I did my share already. :-) <> Larry Lippman @ Recognition Research Corp., Clarence, New York <> UUCP: {allegra|ames|boulder|decvax|rutgers|watmath}!sunybcs!kitty!larry <> VOICE: 716/688-1231 {hplabs|ihnp4|mtune|utzoo|uunet}!/ <> FAX: 716/741-9635 {G1,G2,G3 modes} "Have you hugged your cat today?"
chris@mimsy.UUCP (Chris Torek) (11/13/87)
In article <2223@kitty.UUCP> larry@kitty.UUCP (Larry Lippman) writes: >... Assuming a power line voltage of 365 kV ... we have a voltage >divider and therefore have around 183 kV on the pickup wire. If you live in rural New York, or a few other places, you might be near a 720 kV line, and could double that. >... we will need a transformer with a 183 kV primary - neither cheap >nor simple - nor a particularly safe do-it-yourself project. Indeed. > Actually, the 1,000 feet of pickup wire 40 feet in the air on >poles with huge insulators may make the power company suspicious.... `What's this for?' `Ahh ... it's my radio antenna, yeah, that's the ticket.' On a somewhat more serious note, for what it is worth, my old Junior High Graphics Arts department used to have problems with videotapes fading over the summer. We were a few hundred meters away from a 360 kV line, but I suspect it had more to do with their tape storage cabinet being located too close to the carbon arc lamp used for making silk screens. :-) -- In-Real-Life: Chris Torek, Univ of MD Comp Sci Dept (+1 301 454 7690) Domain: chris@mimsy.umd.edu Path: uunet!mimsy!chris
wtm@neoucom.UUCP (Bill Mayhew) (11/13/87)
When I was in school, I had to suffer though a power systems engineering course that is one of those unavoidable rites of passage to getting one's degree. You know the class, a room full of 1930s vintage 5 horsepower motors and meters with 100 amp scales. The class was run by a person who was a veteran of Ohio Edison. He related a story of a farmer who lived in the vicinity of Mansfield, Ohio where there is a 365 KV line. The farmer, he claimed, had rigged up a power-stealing system ostensibly disguised as a flag pole. He had to construct a monsterous transformer, much as Larry described, that looked like an over-grown Tesla coil. The power thief was caught, the prof claimed, in a rather amusing way. There had been a failure on the local power distribution system. A work crew was dispatched to find the fault. Apparently the work crew becase suspicious when they observed the farmer's house was the only one in the area with lights on and no sound of a back-up generator running. (The failure was on the local system, *not* the 365 KV line.) The prof claimed that Ohio Edison successfully prosecuted the guy for stealing power and forced him to take down his flag pole. Bill Mayhew NEOUCOM (wtm@neoucom.UUCP)
jimc@iscuva.ISCS.COM (Jim Cathey) (11/15/87)
So far as the cost of wire goes, I would imagine that in a farm setting it wouldn't be too hard to come up with a whole bunch of barbed wire.... Of course, insulating it would be kind of tricky, but if the rafters were dry you could just staple it up, going 'round and 'round... +----------------+ ! II CCCCCC ! Jim Cathey ! II SSSSCC ! ISC Systems Corp. ! II CC ! Spokane, WA ! IISSSS CC ! UUCP: ihnp4!tektronix!reed!iscuva!jimc ! II CCCCCC ! (509)927-5757 +----------------+ "With excitement like this, who is needing d liould
noise@eneevax.UUCP (Johnson Noise) (11/17/87)
In response to Larry <whoever>'s back of the envelope treatise which proves that it is not possible to pick off enough energy from high tension wires to light a barn. You are probably right about the small magnetic field, but HAVE YOU EVER HEARD OF ELECTRIC FIELDS, BONEHEAD, uh...I mean larry. FLOURESCENT LIGHTS DON'T TAKE MUCH POWER ANYWAY. "Oh, I've never heard of Nikola Tesla or antennas or Maxwell's equations". WAKE UP!!!! I'm really sorry if I have offended the rest of the net, but this was just too much. The number of idiots on this net who think they know something about anything is overwhelming.
larry@kitty.UUCP (Larry Lippman) (11/17/87)
In article <1103@eneevax.UUCP>, noise@eneevax.UUCP (Johnson Noise) writes: > In response to Larry <whoever>'s back of the envelope > treatise which proves that it is not possible to pick off enough > energy from high tension wires to light a barn. You are probably > right about the small magnetic field, but HAVE YOU EVER HEARD OF > ELECTRIC FIELDS, BONEHEAD, uh...I mean larry. If you had been following the discussion both prior and subsequent to my article to which you now refer, you could have saved yourself some considerable embarrassment. I will refresh your memory: $$> In article <1913@frog.UUCP>, die@frog.UUCP (Dave Emery) writes: $$> > >you could do what a buddy of mine did... $$> > >(his barn was overshot by high voltage lines) $$> > >wrap the rafters with coils, and make off with some free power!! $$> > >his barn had "infinite" lighting this way!!! In view of the word "coils" above, would you care to speculate whether the alleged method of "free power" pickup uses magnetic field or E-field? $$> > I have heard a similar story about farmers in the Midwest using $$> > long stretches of barbed wire fence near long distance power lines for the $$> > same "free" power gambit. As I understand it the power companies were $$> > able to sucessfully prosecute some of them for stealing power. Would you care to speculate on: 1. The effectiveness of E-field pickup using barbed wire 2 to 4 feet above the earth to capture E-field energy emanating from a wire at least 40 feet above the earth at a frequency of 60 Hz? 2. The effectiveness of barbed wire stapled to wooden fence posts in providing the insulation resistance necessary for E-field pickup? In view of (1) and (2) above, would you care to speculate whether such alleged "free power" method operates by magnetic field or E-field? > FLOURESCENT LIGHTS > DON'T TAKE MUCH POWER ANYWAY. Funny, but I already addressed that issue. Why is it that the reference line in your article shows NONE of the three articles that I have already posted on this topic? "Oh, I've never heard of Nikola > Tesla or antennas or Maxwell's equations". WAKE UP!!!! Perhaps you could tell us how 60 Hz compares with the frequency domain used by Tesla in his wireless power distribution work. Perhaps you could also tell us how Maxwell's equations help to prove your point since: (1) the first equation is essentially a statement of the inverse square law as applied to the electric displacement field vector; (2) the other three equations involve either the magnetic induction or the magnetic intensity field vector? Invoking Maxwell's name in your behalf does sound impressive, though. > I'm really sorry if I have offended the rest of the net, but this > was just too much. The number of idiots on this net who think > they know something about anything is overwhelming. You haven't offended anyone, but you have clearly demonstrated yourself to be a member of the "idiot category" to which you refer. Perhaps a little more signal and less "Johnson Noise" from you would be in order. <> Larry Lippman @ Recognition Research Corp., Clarence, New York <> UUCP: {allegra|ames|boulder|decvax|rutgers|watmath}!sunybcs!kitty!larry <> VOICE: 716/688-1231 {hplabs|ihnp4|mtune|utzoo|uunet}!/ <> FAX: 716/741-9635 {G1,G2,G3 modes} "Have you hugged your cat today?"
jeffl@sequent.UUCP (Jeff Lindorff ) (11/18/87)
In article <2226@kitty.UUCP>, larry@kitty.UUCP (Larry Lippman) writes: > In article <1788@bloom-beacon.MIT.EDU>, eichin@athena.mit.edu (Mark W. Eichin) writes: > > I suspect it would be electric, not magnetic field effects that > > matter, mainly from the propaganda stuff I have seen with people > > walking under high-tension lines holding Flourescent tubes and having > > them glow... > > It only takes a few microamperes of current at several hundred volts > to ionize the gas in a fluorescent lamp. If you held one end of the lamp in > one hand, while pointing the other end upward toward the power line - you > may well have a sufficient potential difference to ionize the gas - provided > you can get close enough, and provided there is enough voltage (lower voltage > lines like 4.16 kV won't create enough of a field close to the ground). The > lamp won't be bright enough to be really useful, however. I work for an FM broadcast station that has 5 other FM's sharing our building and tower. All are 100kw ERP. Something rather eerie about turning OFF the lights in the building and having them stay ON just bright enough to read by. This effect diminishes rapidly with distance from the transmitters, and dosen't work at all outside the building. The lowest antenna is about 180 feet off the ground. $0.02 Jeff (Not employed by Sequent Computer Systems, Beaverton, OR., so don't blame them.) ---------VOID WHERE PROHIBITED---------------------USE ONLY AS DIRECTED--------- "I know it's true. I saw it on T.V." -- John Fogerty
dave@sdeggo.UUCP (David L. Smith) (11/18/87)
You know, I like sci.electronics because it has such a low flame content.
Please don't flame here. If you think you're right, produce the facts,
otherwise keep your opinions to yourself.
--
David L. Smith
{sdcsvax!man,ihnp4!jack!man, hp-sdd!crash, pyramid}!sdeggo!dave
man!sdeggo!dave@sdcsvax.ucsd.edu
The net.goddesses made me do it!KEN@ORION.BITNET (Kenneth Ng) (11/18/87)
>From: eichin@athena.mit.edu (Mark W. Eichin) >I suspect it would be electric, not magnetic field effects that >matter, mainly from the propaganda stuff I have seen with people >walking under high-tension lines holding Flourescent tubes and having >them glow... someone want to work out that math? > > Mark Eichin > <eichin@athena.mit.edu> Lighting a flourescent bulb doesn't take much. My dad's electric fence took the output of a car ignition pulsed at 1 millisecond, cycle time 1 second. After going through a fence about 20 feet long, holding one end near the fence would create dim flashes from the end to where your hand held the bulb.
robert@uop.EDU (/dev/null) (11/20/87)
i was bringing home some flourescent tubes in the backseat of a VW bug as a kid, (dad was driving) and there was a rain storm outside the car, the tubes were 8' long, and stuck out the front window... i found by accident, that as i moved my hand along the tube, it would light up under my hand! my sister thought i was nuts, and my dad did not want to look in the rainstorm... (yes it was dark!!) there is a picture in an old life magazine, and i think it made it into the time life series on photography, of some protestors waiving tubes around under some high voltage lines... all lighted up!!
robert@uop.EDU (/dev/null) (11/20/87)
of course, with a coil built along the proper parameters,
you don't even need the power company, but the last guy who
did this is... er, indesposed at the moment...
(if you want to know send e-mail)
sci.tesla lives!!
mcvax!uunet!mit-eddie!garp!ames!ucbvax!ucdavis!\
...princeton!rutgers!retix!--uop!robert
...sun!ptsfa!cogent!/ dennisg@felix.UUCP (Dennis Griesser) (11/21/87)
In article <1103@eneevax.UUCP> noise@eneevax.umd.edu.UUCP (Johnson Noise) flames Larry Lippman and winds up: >I'm really sorry if I have offended the rest of the net, but this >was just too much. The number of idiots on this net who think >they know something about anything is overwhelming. If you have been reading the net for more than a short while, you should know that Larry really DOES "know something about anything". I don't follow Larry's postings blindly, but he is seldom wrong. And the scope of his expertise is amazing. Who are you going to flame next? Henry Spencer?
wolfgang@mgm.mit.edu (Wolfgang Rupprecht) (11/21/87)
In article <767@uop.EDU> robert@uop.EDU (/dev/null) writes: >i was bringing home some flourescent tubes in the backseat of a >VW bug as a kid, (dad was driving) and there was a rain storm >outside the car, the tubes were 8' long, and stuck out the front >window... Another source of flourescent tube lighting energy is a radio or microwave transmitter. I know because I live 3 blocks away from the Prudential Tower (in Boston). The Pru is one of these buildings that in only surpassed by Russian "Fishing" trawlers for the number of antennas on its roof. Every once in a while, (I suspect when they are setting up a new antenna), I notice that my 4 ft. plant light glows enough to navigate the room by. Now, if it were to light up brightly, I would probably run to the kitchen to get the Reynolds-Wrap and wrap myself with it... ;-) --- Wolfgang Rupprecht UUCP: mit-eddie!mgm.mit.edu!wolfgang (or) mirror!mit-mgm!wolfgang ARPA: wolfgang@mgm.mit.edu (IP addr 18.82.0.114)