this guy dont want much out of life - Page 1
Forum section: electronics / general

author: Unknown
author_rank: Unknown
timestamp: May 01, 2012, 10:45:07 pm
content: Misinformed and proud of itOn a side note I wonder how big a coil is needed to harvest 1kW from an aerial power line say 375kV when parked underneath. I doubt if 2000 bucks wold be enough for that as it would need its own wheels perhaps.

author: sonicj
author_rank: Frequent Contributor
timestamp: May 02, 2012, 01:06:33 am
content: he could build a couple kW pv system for less than $4k...Bare cells $600frames $?batteries $1kinverter $1kwire $500misc $?would likely be a much better use of funds than some cobbled together box of tubes and pixie dust. plus, if he goes the diy route, it would be less wear and tear on his telepathic lie detector machine.-sj

author: Lightages
author_rank: Unknown
timestamp: May 02, 2012, 01:54:33 am
content: Actually for what he wants it would cost a bit more for a solar system than $4K. Probably more like $15k

author: Kremmen
author_rank: Super Contributor
timestamp: May 02, 2012, 05:48:19 am
content: Quote from: HAL-42b on May 01, 2012, 10:45:07 pmEnormous. Mythbusters debunked this one though i can't recall the episode number or season. Anyway, they constructed an unreasonably large coil, much bigger than what anyone would really care to do, raised it just under the power cable and got nothing. Zilch. Like a couple of millivolts if that.

author: Pentium100
author_rank: Frequent Contributor
timestamp: May 02, 2012, 06:22:35 am
content: Quote from: Kremmen on May 02, 2012, 05:48:19 amBut maybe lots of kiloamps (they didn't measure the current IIRC).Maybe you should wind the coil around the high voltage wire, like a giant current transformer, though by that point you might as well just attach a wire to the high voltage wire and build a step down transformer.There is enough power tolight up a bunch of fluorescent lampsthough, so maybe the coil used to take the power has to be different shape (fewer windings but larger core area or something. Or a coil positioned under the wire so the magnetic field passes trough its core, unlike what Mythbusters did (they lifted the coil to the side of the wire).

author: siliconmix
author_rank: Frequent Contributor
timestamp: May 02, 2012, 07:19:35 am
content: usually i dont listen to these overunity pot at the end of the rainbow dribble drabble.but this vid was on the right hand side bar when i watched photoinduction's last and he looked at my old lecturer but not so crazy.

author: Kremmen
author_rank: Super Contributor
timestamp: May 02, 2012, 09:00:06 am
content: Quote from: Pentium100 on May 02, 2012, 06:22:35 amYes i am sure they could have got more out of the coil in some other orientation but come on. This idea is stillborn and demonstrated to be so. All the manoeuvres you would need to extract any useful amount of power make the system either a real rube goldberg machine and/or something illegal and you land behind bars (at least in the US where that apparently solves all problems...)

author: Pentium100
author_rank: Frequent Contributor
timestamp: May 02, 2012, 10:02:11 am
content: Quote from: Kremmen on May 02, 2012, 09:00:06 amYea, it probably is impossible to extract useful electricity cheaply enough so that it is actually worth the effort. Still, the display with the fluorescent lamps is impressive, however, it probably is only a few watts per lamp, so the total is not that much.

author: Neilm
author_rank: Super Contributor
timestamp: May 02, 2012, 06:12:28 pm
content: Quote from: HAL-42b on May 01, 2012, 10:45:07 pmIf he did that in the UK it would be an illegal connection to the power network for which very heavy fines can be imposed. I read about a case a few years ago when someone defense for this was he was "harnessing radiant energy". He lost.Neil

author: Kremmen
author_rank: Super Contributor
timestamp: May 02, 2012, 06:42:13 pm
content: Quote from: Pentium100 on May 02, 2012, 10:02:11 amWhile showy, no way is it going to take watts to light up a fluorescent tube that way. As a schoolboy i worked in a lab building high power microwave transmitters and we looked for leaks in the waveguides using a fluorescent tube. You can see the minutest of leaks easily. I would say microwatts rather than watts, but haven't really checked. And it could be somewhat frequency dependent, i don't really know.

author: PetrosA
author_rank: Frequent Contributor
timestamp: May 03, 2012, 03:18:57 pm
content: The last case study I read took place in Canada, where a neighborhood (approx. 5 blocks long and one block wide) was laid out parallel to HV lines. Their cable connections started burning out and it turned out that about 10A was leaking out of the cable to the earth bond at each residence. A cable company employee had closed the loop running around the neighborhood instead of dead ending it. It was enough to open the loop and the fault current went away.

author: G7PSK
author_rank: Super Contributor
timestamp: May 03, 2012, 05:23:38 pm
content: Lines are not allowed to parallel EHT lines in the UK there have been cases in the past where it happened and lethal voltage has been induced on phone lines and in one case in the 1930's a linesman was killed due to the incorrect earthing of the line he was working on that was running along side a live line. There is an 11KV line just down the road from me when it stops raining I will wander along with a test meter and a meter of wire and see what voltage is induced at what distance.

author: SeanB
author_rank: Super Contributor
timestamp: May 03, 2012, 08:24:35 pm
content: Well, in the USA the pole transformers have a common ground with the primary and secondary...........At least here the earthing points are separate physically, and are at opposite ends of the substation. does not help though when the copper thieves steal all of it, then the neutral bus and wiring.

author: free_electron
author_rank: Super Contributor
timestamp: May 03, 2012, 10:25:34 pm
content: Quote from: G7PSK on May 03, 2012, 05:23:38 pmyou'll probably see a lot of volts , but try to draw 1 milliampere from it and it will collapse to snot...

author: vxp036000
author_rank: Regular Contributor
timestamp: May 03, 2012, 10:47:08 pm
content: This is correct; there will be very little power transfer because the distance is so great from the voltage source. Think of the power lines as simply a twin lead transmission line. A balanced transmission line has very little radiation. The only practical way to get any useful power out of it would be inductively couple a coil to the HV lines, but that would only be effective over a very short distance.Quote from: free_electron on May 03, 2012, 10:25:34 pm

author: G7PSK
author_rank: Super Contributor
timestamp: May 04, 2012, 07:54:00 am
content: The problem is when the distance is a few yards of separation but the cable distance is miles you can soon get both voltage and current.

author: Noize
author_rank: Regular Contributor
timestamp: May 05, 2012, 01:41:51 am
content: lol

author: elliott
author_rank: Regular Contributor
timestamp: May 05, 2012, 02:58:02 am
content: Quote from: Noize on May 05, 2012, 01:41:51 amHe sure used some fancy words, he must be right.

author: Unknown
author_rank: Unknown
timestamp: May 05, 2012, 05:18:48 am
content: If you want to flex your brain muscles here is an interesting document:http://www.nationalgrid.com/NR/rdonlyres/4DD2D3FF-B973-4F3C-A8C3-CDB640526660/45082/Developmentnearoverheadlines.pdfSome data from the document as a basis of a calculation:Line voltage - 400kVPole type - L6 or L12, three phase, double circuitAllowable minimum clearance -7.6mto ground, more to road surface. (notice it does not actually say "safe")Electric field - In excess of4kVmat distance of approx 10mMagnetic field - In excess of5uTat the centerline (on the ground)Current carried - unknown (unlikely to be under utilized), can be derived using Ampere's law.