[graham.d]

I guess there would not be a problem with ending up with a DC voltage across a capacitor where one side is X volts more negative wrt ground and the other X volts more positive wrt ground as such, unless as you say, you are trying just to supply a DC supply wrt to Ground. I don't know much about electric fences but when I remember getting shocks from these things when trespassing on farmland as a lad it felt like AC (or at least pulsed).

To end up with something that may be more flexible, how about connecting to collector capacitor to a transformer primary with the other primary input at ground? The secondary would then be isolated and could be managed like any other AC power source.

[evan_au]

Talking to someone in the power industry, high-voltage transmission lines typically run around 400 Amps during peak hour, which will produce a magnetic field extending beyond the wires themselves (to infinity, in theory).

As noted in a previous post, the balanced currents in the 3-phase wires sum to zero, so the magnetic field drops off much faster than the field around a single conductor. A receiver coil would need to be carefully positioned relative to the geometry of the wires for best collection efficiency.

The ideal position for a coil to collect power from the transmission line would be directly around each individual conductor (like a current transformer) - but I am sure that would be illegal, as well as extremely dangerous: The transmission line operates at high voltage, and current transformers generate dangerously high voltages if they are left open-circuit for even an instant.

[evan_au]

A capacitive pickup suffers from extremely high source voltage, but extremely high source impedance.
An inductive pickup has the opposite problem: very low source voltage and very low source impedance. Even a single silicon diode would block the power output from a small coil.

A resonant circuit helps overcome some of these problems - with a source capacitance of 500pF, you would need an inductor of around 6000H to resonate at mains frequency (ideally with low resistance). But the resonant circuit can still produce dangerous voltages.

[syhprum (OP)]

The situation with a bridge rectifier is worse than what you suggest (open up a switched mode PSU with a bridge rectifier input and check what appears on the terminals of the storage capacitors with a meter or oscilloscope you will find half the input AC voltage on both terminal's of the capacitors).
you can only use a bridge if you have either a floating or bi-Phase input.
An input transformer or resonant inductor would certainly help but would be difficult to source!
If you don't mind your PSU being mounted on the actual power line which is OK for powering radio telemetry equipment commercial units are available using a capacitive pick a bridge rectifier and a chopper as we are not interested in ground connection for this application.

PS talk of using a resonant circuit made me wonder if a quartz crystal could be used the lowest frequency one I have encountered was 4.8 kHz so a 50 or 60 Hertz one might be possible.
PPS A resonant circuit fed from a magnetic pick up might be the way to go with the more practical values of approximately 1 Micro Farad and 10 Henries
A 1 meter diameter coil with 2000 turns would have an inductance of about 10 Henries. 

[CliffordK]

Clifford, I think the setup you tried could not work. It is not clear whether you are trying to gather power by the inductive coupling of parallel wires or by capacitive coupling. If the former you should try grounding the left hand end of the collecting wire, then have (say) a full wave rectifier connected to a grounded capacitor. The ground is a "return path". If trying to utilise capacitive coupling it would be best to get the collecting wire as high (close) to the power lines as you safely can then connect a full wave rectifier between the wire and a capacitor with a vertical wire to ground. In either case the power available is limited by the fact that the lines will be placed as a transmission line and the losses to ground minimised by the height and spacing. I would have thought you should get some power out of it though.

I doubt the power company will like me if I climb their tower, and hang my collector a few feet below their transmission lines.

I already have my electric fence wires under their tower so they can't say much about that, and if they do, I could just remove the wires.  "Agriculture" is legal below the power transmission lines.

Earlier when I was testing, I just used my multifunction tester, with no additional circuitry.  I don't remember if I tried AC or DC, or both.  I was getting some small "ghosts" of values, but couldn't be sure it wasn't static from my fingers or something.

I thought about my circuit some more over the last few days and came up with some "updates", in particular feeding the ground into the rectifier.

 [ Invalid Attachment ]

My biggest problem is thinking where one would connect both the + and -.

Perhaps adding a ground into the linear collection circuit (capacitive)

An alternative might be to just make a coil collector (magnetic).

[syhprum (OP)]

I have written this many times but I do not know if has been appreciated if you use a bridge rectifier with a grounded source you get half the input AC superimposed on both the positive and negative terminals unless you are going to feed a chopper and then isolate it with a transformer this renders it pretty useless where as if you use a voltage doubler circuit you can use the DC output directly with a grounded load. 

[Banjo27]

Is there any progress on this ??
I have a transmission line tower on my land and would love to power things using the EMF
Spend enough time under them and touching another person you will make a spark , my vehicle has a faint vibration to it when touching the body from the outside when I'm near the lines aswell

[syhprum (OP)]

An antenna strung along below a high voltage power line will harvest a small amount of energy but because the low frequency the source impedance will be very high and the amount of energy that can be harvested (stolen?) is very low.
You could feed the antenna into the junction of a pair of high voltage rated diodes with a capacitor between the two ends and one end grounded and it would gradually charge up but I repeat the voltage would be high and the source impedance very high not a very useful source of power!   

[alancalverd]

"Stolen" is indeed the correct word. Whilst you might get away with the occasional demonstration of fluorescent tubes and the like, if you harvest more than a few watts on a regular basis and somebody grasses on you, you will be liable for "Theft of Electricity" - the fine might be nominal if the quantity was small but you will end up with a criminal record that can do disproportionate damage to your career.

[Dezeinstein]

I think you guys are going about this all wrong. The energy isn't in an inductor, so why would an inductor induce this? the field is in the incorrect direction, so to get anything out, you may only have to use capacitive plates and an avramenko plug across the plates to output some energy. The smaller the diodes, the better your safety factor. This way if the voltage is too high , the diodes will explode. try this, put a copper plate on the top, glass in the middle and aluminum plate on the bottom. use the don smith experiment but in reverse. Take the plates, cut a hole at 2" in the middle of the plates and your dielectric (which could be mica, glass, or any high enough energy dielectric to start. If you use a staticly charged plastic plate, be very careful, the output will attract the ions of the line and may belt you!..

I think if you add an iron rod through the holes and make a non conductive holder that will have a hole in it so the rod could stand in it, then the non conductive holder could be pushed into the ground, this would work. place a thick paper wrapping around the bottom of the rod and wind a coil of about 200 turns under the plate. The plate will need to be grounded on the bottom plate, and the top not connected.

The rod's coil will need to be grounded on one end and the other conductor will be connected to an analog voltmeter between the top coil connection and the grounded one. If this gives nothing, connect the top plate to the meter and the unconnectded coil winding.

If this doesn't work, you'll probably never get the field propagation correct. The capacitive plate and coil will need to be built to resonate at 60 hz to transfer energy from the power lines to the plate and coil. You also have no reference to ground from a delta overhead system, this means if there's only 3 phases and no neutral line, the energy across from phases to ground will not be existent and the energy will not be able to be induced.

When you run a line straight like this, you need a component to be energized at the end of it, like a choke or a very high voltage, very small capacitance cap. you would need an avramenko plug on both sides, one side would need to be grounded and a coil in series with the lower transmission line you build. Then the avramenko plug may release energy. If you connect one side to ground, the inductor or choke of a fairly high resistance will need to be wired in series between ground and the rest of the line, then an avramenko plug mounted to the other side, or, the line could be connected to a capacitive plate at the end of the rod used for the choke to collect the transmitted energy with the plates connected at a 90 degree angle to the choke or resonant inductor's core. Holes should be drilled through these plates and the capacitve nature of the plates should be calculated to ensure it will resonate at 60hz, otherwise you will NOT have a loose inductive coupling.

The plate could be used to draw dc energy from it, then transferred to ac with a battery and an inverter, so this may be a  wise try.

What I was saying before about the delta lines means that the delta system has no neutral and no ground. The energy returns on opposing phases because the coils of the generating equipment are tied together and placement of the coils are placed 120 degrees apart, hence 3 120 degree difference in phases. If the system is stepped up to 69kV, 115kV, 138kV, or 345kV, you should be able to see if there is a 4th line. The 4th line may indicate a grounded line (which is a static line), or, if you live in southern states or different countries, these may be grounded neutrals, or the lines could even be dc transmission lines which you could capacitively collect energy from, but I will warn everybody, be careful. The dc lines could strike and kill you. remember Tesla's statement about the blue streak of death!

Anyway, I have created two images, one I believe may collect small amounts of energy from both wye and delta transmission lines. remember, these are not designed to steal piower, they are for educational purposes only. I am not suggesting anybody go on the federally owned transmission line's right of way. It's a major charge and they would lock you up for sure. If you have land abutting the transmission lines, you may be able to collect something, but it shouldn't be anything that adds load to their lines if done capacitively, as well, the energy may if youre lucky light a few leds. If you make this to couple with the lines, you may be in for a big surprise, it may easily kill you and I am not suggesting anybody try this, not even from 200 feet away,. which is very possible. If tesla could run a car by driving within 1/4 mile of the transmissiobn lines, then we could somehow harvest the energy using a method similar to this!

GOOD LUCK AND PLEASE REMAIN SAFE USING ALL PROTECTIVE SAFETY EQUIPMENT. HIGH VOLTAGES CAN KILL WITH EVEN 1/2 AMP OF CURRENT, IN FACT, AT THIS LEVEL IT COULD BLOW OFF LIMBS ARE COMPLETELY BURN EVERYTHING OFF OF YOUR BODY. FLESH CAN INSTANTLY BURST INTO FLAMES, AND THERE WOULD BE NO WAY ANYBODY COULD SAVE YOU IF THE POTENTIAL IS TOO HIGH.

iF ANYBODY TRIES THIS, I SUGGEST YOU PUT THE DEVICE TOGETHER AND CONNECT A METER TO IT, THEN FROM A VERY LONG DISTANCE, BE SURE YOU CARRY IT WITH RUBBER GLOVES, WALKING TOWARDS THE LINES, WATCHING THE METER WHICH WILL MEASURE VOLTAGE ACROSS THE PLATES, AND ANOTHER METER ACROSS THE COIL FOR ADDITIONAL SAFETY.

PLEASE BE CAREFUL. SEE IMAGES BELOW.

Dezeinstein

newbielink:http://www.thenakedscientists.com/forum/index.php?topic=27039.msg286115#msg286115 [nonactive]

[syhprum (OP)]

You are not going to get anywhere with small structures , low frequency's require large structures look at the antennas at droitwich or those used by the military to communicate with their submerged submarines.   

[FREE ENERGY]

Harvesting electricity from power lines
WARNING! Trying this experiment involves incredibly high voltages! Do not be a stupid scientist. Do not conduct this experiment on anything but calm days. Fasten and know where the antenna wire is at all times. There can be no large slack in the wire at any time. You must be at least 30 feet from the power line! Make sure you are an electrician, electrical engineer, ham radio operator, electrical student or have years of electrical experience. You must understand what is being presented here in its totality. Also, this is illegal! Conduct your experiment and then remove everything from the site.
If you run a single wire along a high voltage power line, (= or> 340KV), you will harvest a fair amount of voltage at micro amp levels. WARNING: KEEP AT LEAST 30 FEET FROM THE HIGH VOLTAGE LINE!! Use small gauge solid bare wire hung from fishing line for insulation and support. The longer the wire, the higher the voltage.  Use a fishing pole and weight to put up the wires in the closest branches along the right of way. Run your (antenna) parallel to the power line in the trees adjacent to one outer phase of the power line. The higher, the better. Run at least 200 feet of bare antenna wire. The wire must not touch any vegetation. WARNING, DO NOT TOUCH THE ANTENNA WIRE! YOU WILL GET SHOCKED!  Commercial rubber gloves work well for this. The goal is to present a minimum load to the antenna wire and to step down the electrostatically induced voltage using transformers. Provide a single or several 5 foot ground rods at your termination point for the transformer high voltage secondary return. Ground the antenna right away! We then connect a high voltage transformer secondary winding, (a ham radio plate transformer rated at 10,000 volts to 220 volts / 115 volts. A 15 kilovolt neon sign transformer is better). voila! You have usable power from the AC input terminals of that transformer. You have created a capacativly-coupled step-down transformer. Your final voltages off the low side of the transformer may be from 150 VAC to .5 VAC. Place a 4 watt, incandescent 120 volt light across the 120 volt terminals of the transformer. Ground the Antenna wire while you work until the transformer is installed and you are ready for power.  Removing the antenna clip from the ground rods allows the AC voltage to the light bulb. If the bulb pops, then you need still another step down transformer, say, 600 volts to 120 volts. Another transformer can provide more current. If the bulb does not light, (too much resistance), then remove the lamp and add a full wave rectifier and a 100 VDC, 10 microfarad capacitor. Measure the DC voltage. Can you run a small radio with this current? Charge a cell phone? Run a small ham radio? Run a small DC fan? Light up your campsite? The antenna by itself can also light up many florescent tubes at one time. Use the ground return for the other end of the florescent bulbs. Please be safe and work slowly!!

[alancalverd]

...and don't get caught. See reply #28 above. You may not receive a prison sentence for a first offence but theft of electricity is a crime for which you could forfeit any public service pension or membership of any professional institution - in other words, the guys who can best do this safely are the least likely to do it!

[syhprum (OP)]

This may well work out some of the most expensive power that you have ever obtained considering the cost of the equipment and the legal and physical dangers
Unless your antenna wire is very long the output impedance of the capacitive divider formed by the capacitance of the antenna wire to ground and the capacitance of the antenna wire to the high voltage line will be extremely high so although the open circuit voltage may well be 43KV as soon as you connect the transformer it will drop to a very low value.
If you must do this experiment connect the output of the antenna to a half bridge rectifier (using expensive diodes and use the resultant DC output to a chopper circuit a high frequency transformer) .
You would get cheaper power hiring an illegal immigrant to turn a hand generator.