What is the optimal design for loop antenna made of copper stiff wire to transmit at 81.39–90.00 kHz?

[wizabin]

The research aims to devise an optimal copper loop antenna design specifically for testing magnetic field intensity within the frequency range of 81.39–90.00 kHz. The focus will be on selecting appropriate dimensions, materials, and configurations to ensure accurate and reliable measurement of magnetic fields, particularly relevant for wireless charging scenarios compliant with the SAE J2954 standard.

 

[Martaine2005]

Check this calculator https://www.southwestantennas.com/calculator/antenna-wavelength.

Martin

 

[Delta Prime]

, particularly relevant for wireless charging scenarios compliant with the SAE J2954 standard

Stay with copper.
We are in competition.
Research for profit! That's big money! Can't give away my secrets.
“Charging your EV should be as simple as parking and walking away – the wireless charging SAE J2954 Standard gives freedom and convenience to do exactly that, safely and automatically,” stated Jesse Schneider, chair of the SAE J2954 Task Force. WPT systems work by parking in a wireless charging spot, with the vehicle positioned over an SAE J2954-compatible ground assembly pad. After a communications handshake, charging begins automatically without a physical
corded connection.
(WPT) stands for Wireless Power Transfer.

 

[kellys_eye]

As if charging EV's isn't difficult enough - introduce yet another step of efficiency loss in power transfer....... yeah, that'll help the grid.

 

[Delta Prime]

Transmitting energy by electromagnetic fields through an air gap without any interconnecting cables is state of the art technology normally it is conducted in microwaves but now it could be done at much lower frequencies besides it's what the masses want. It has transformed my pigs ear into a silk purse.
It's a gravy train open to everyone. All you have to do is submit your idea and have a working model. Cha! ching!

 

[Martaine2005]

@Delta Prime
For someone’s sake, construct a sentence!. It’s no good showing off your prowess if we can’t read it!.
Reread before you post please.
You are clearly a well educated and young individual, that knows his stuff. Take a chill pill and respond properly.

Martin

 

[hevans1944]

Transmitting energy by electromagnetic fields through an air gap without any interconnecting cables is state of the art technology normally it is conducted in microwaves

Yep, microwaves is one way to do it. An old proposal (maybe 50 years old?) was to orbit giant solar photovoltaic panels to harvest energy from the Sun, convert the direct current (millions of amperes) to microwave energy, beam the microwaves down to giant rectifying microwave dipole (rectenna) arrays, convert the current from the receiving arrays to three-phase AC for grid interface. Or convert the current to a higher voltage for long-distance DC transmission lines.

At my home we get some of our electricity from PV panels installed on the roof of our house. We harvest enough energy to "run the meter backwards," or so-called net-metering, and sell our "excess" energy back to Florida Power & Light. There is a small monthly fee that helps pay for the infrastructure provided by FP&L. Some inefficiencies in the microinverters, seasonal limitations on sunlight, the time-of-day, clouds, rain, various other random atmospheric events and minor variations in the radiation flux from the Sun means we don't get to harvest all the "free" energy that is sent from our gravity-contained, thermonuclear, spherical reactor parked (on average) a relatively safe ninety-three million or so miles away. It is free for anyone, anywhere, to use this reactor, but your mileage (or kilometers) will vary with geographic location and economic capability.

Believe it or not, I recently read (somewhere) that someone is reviving the idea of space-based energy harvesting, with the harvested energy beamed down to Earth. I imagine it is possible for such a system to be designed to supply electrical energy to end-users anywhere in the world, day or night. Power generation too cheap to meter until it is delivered to customers. Hmmm. Didn't that old guy, Nicola Tesla, propose something similar, but without the solar panels? And without metering? No wonder he died poor.

I don't remember what frequency or wavelength of electro-magnetic radiation was being proposed for this "new and improved" power-from-the-sky (PFTS) scheme. It was either microwaves from giant traveling-wave tubes (easy to construct in the hard vacuum of outer space) or massively parallel bundles of fiber optic lasers, the latter being solid-state diode-pumped and probably pulsed. I am going to rectally extract an estimate of at least 1x10⁹ watts per orbiting transmitter, and a cost of perhaps 100 trillion dollars over a ten-year period for launch services, space hardware, and maintenance. This PFTS scheme would connect to the electrical grid that is already in place near the receiver farm, but in the United State of America the grid infrastructure is old and in need of replacement.

Further improvements in more economical (reusable) launch capabilities, improvements in solar panels, and refurbishing of existing grid elements will allow a better cost estimate if some global entity would take an interest in securing funding. Maybe a world-wide initiative is in order, something at least on the order of whatever is being spent in an attempt to modulate Earth's climate. If such "cooperation" should occur, please multiply my previous estimates by a factor of at least one hundred.

I think it was the late Arthur C. Clarke who first postulated that only a few satellites in Geo-synchronous orbit (about 42,000 km) would be necessary to link everywhere on Earth for communications purposes. We humans, being competitive more than we are cooperative, have already placed thousands of (mostly junk now) satellites in low-earth orbit, and at least 300 in Geo-synchronous orbit... well, at least that far out there is still plenty of room and a very hard vacuum, so station-keeping is not a big problem.

Charging vehicles inductively makes absolutely no sense, unless the energy is free. If you want a FAST charge, just replace the battery with one that is fully charged. Drive over the lift mechanism and get out of the vehicle. When a safe distance away, perhaps in a separate windowed room, like at a car wash, you could insert your credit card in a reader to start the exchange and billing process.

now it could be done at much lower frequencies

So what? It is still waaay too inefficient for anything that requires more charging capacity than a cell phone or vape pipe or a modern "tactical" flashlight. My iPhone charges overnight from an inductive charging pad, but I normally keep it charged with a wall-wart and a USB-to-Lightning cable. I cannot even imagine charging a battery electric bicycle from an inductive pad. However, an electric bicycle does not appear to meet my needs. Range is okay, but the prices are outrageous. If I can find a used bike with a user-replaceable battery at a reasonable cost, I would probably consider buying it for short trips in and around Venice, FL.

Unfortunately, I haven't found any electric bikes yet that can keep up with the traffic on US-41 (Tamiami Trail) that connects Tampa with Miami, and my house with the island city of Venice and nearby shopping. The speed limit on US-41 within Venice is 45 mph, but it increases to 55 mph on some segments between Venice and Sarasota and between Venice and points further south. I haven't found any electrical bikes that will go that fast. My wife won't let me ride my 1100cc Honda American Classic Edition motorcycle unless I convert it to a trike, but it can certainly keep up with traffic.

Unlike propane tanks, where the exchange process of empty tanks for full tanks is well established, batteries lose their charging capacity over long periods of time, whether used or not. If the vehicle batteries are made with electronics that keeps track of how much charge was removed from the battery, and how often and when the battery was discharged and recharged, good estimates of the remaining life of the battery can be made.

A life-remaining estimate is essential because you are exchanging a battery in unknown condition for a fully charged battery that may not be new, but is guaranteed to have some level of charge. You need to be billed for the energy that was used to charge the exhange battery, as well as for the cost to replace the battery, amortized over the anticipated life of the battery. That latter part of the cost can be somewhat compensated by the value left in the battery being exchanged. In other words, if the battery you are exchanging has 85% of its anticipated life left, then about 85% should be deducted from the cost to replace it. All sorts of room for fudge factors, and profit enhancing, and taxes when calculating how much to charge and make a profit. Of course if you live in a Utopian society where everything is free... never mind.

I think battery swap, instead of battery charge, is going to have to be the near-term transition to battery electrical vehicle
acceptance. It is the ONLY way to preserve the long-haul capabilities of fossil-fueled engines, whether that be on cars, trucks, air planes or ships at sea. We gave up on nuclear-powered merchant marine, probably because some ports will not allow nuclear-powered vessels to dock. But quick-change, snap-in batteries, in sizes up to the trailer size of a 18-wheel tractor/trailer rig... not a problem. Six or so batteries of that size should be enough to power a freighter at least half-way around the world. After docking, shore power can recharge the ship's battery. This would also allow (require, actually) the exchanged batteries to be shipped to a bulk-charging location, which would be constructed where sufficient amounts of power are available with low transmission losses to service perhaps a hundred batteries per hour. Truck stops on steroids. Or maybe convert some of those drive-through oil changing stations to battery exchanging stations. Electric vehicles don't need much lubrication.

I doubt any of these measures will save the planet for my grandchildren.

 

[kellys_eye]

Six or so batteries of that size should be enough to power a freighter at least half-way around the world.

1 ton of oil equates to around 11.6MW of electrical energy. An average size freighter (global freighters average 50,000 grt) will consumer 100-120 tons of oil per day.

The electrical equivalent would require batteries to deliver over 1GW per day (equal to 50MWhr - EVERY HOUR - and that's only for one day!). We're talking TWENTY Tesla vehicle batteries per day.......... it takes around 30 days to circumnavigate HALF way around the world. So 600 Tesla batteries.

Imagine the chargers required too! Not to mention there are around 13,000 container ships, 30,000 oil tankers and 43,000 bulk carriers trading globally - not counting smaller coastal vessels.

Current global lithium production couldn't even cover the total vehicle requirement for the UK never mind ships on top of that - or other countries vehicle requirements. Such ideas are speculative in the extreme!

I don't see - ever - a vessel with that kind of battery capacity.

 

[Delta Prime]

Yep, microwaves is one way to do it. An old proposal (maybe 50 years old?)

I said state-of-the-art brother.

Transmitting energy by electromagnetic fields through an air gap without any interconnecting cables is state of the art technology normally it is conducted in microwaves but now it could be done at much lower frequencies besides it's what the masses want.

Just keeping the cards straight.
Aces and eights. The dead man's hand.
And of course I'm the joker.


All jokes aside.
I have been invited to visit
Sandia's Z machine. @hevans1944 Were you a part of the Z machine team?

 

[Delta Prime]

So what? It is still waaay too inefficient for anything that requires more charging capacity than a cell phone or vape pipe or a modern "tactical" flashlight

Sorry you did keep the cards straight.

 

[Delta Prime]

I doubt any of these measures will save the planet for my grandchildren

The real question is did you tell your grandchildren Your generation is responsible for this mess and that our generation must implement artificial intelligence to help us?

 

[kellys_eye]

Your generation is responsible for this mess

In a political sense you could be correct but if you're referring to the climate, environment etc you're wide of the mark.

 

[hevans1944]

I don't see - ever - a vessel with that kind of battery capacity.

Puleeze! The figures I cited as estimates were just that: pulled them straight out of my ass. Thanks for providing some actual (I hope) information. However, I do not share your pessimism concerning battery-powered shipping. It's coming, maybe not "real soon now," but eventually. Battery technology is in the Dark Ages compared to internal combustion (or even external combustion) technology. It is VERY difficult to meet the energy density of fossil fuels without resorting to non-chemical means, such as nuclear fission.

If the human race survives this century (I am not very optimistic about that), it will need ever-increasing amounts of energy that fossil fuels simply cannot provide. For that reason alone we should seek alternative energy sources to fossil fuels. It has nothing at all to do with "saving the planet." Fossil fuels are even more useful as a source of the hydrocarbons that are essential to the synthetic organic chemistry used by modern society. It seems really stupid to me to "waste" them by simply burning fossil fuels, only for the energy stored in them long ago by our Sun through photosynthesis in plants consumed as food by all living organisms in the food chain. Oh, well... the problem goes away when humans harness what is essentially the infinite energy contained in star thermonuclear reactions. With enough energy, and a means to dissipate the heat waste produced when using any source of energy, any chemistry can be synthesized from basic elements. With enough energy, humans could direct our solar system on a tour through the Milky Way Galaxy... we are all going along for the ride as it is, so why not choose which way to go?

It takes "billyuns and billyuns" of years for our solar system to make just one orbit around the black hole that is at the center of our galaxy. Who knows what sort of interstellar gasses or left-overs of creation the solar system encounters on this journey among the stars? What effect does the interstellar environment have on the amount of energy intercepted by the Earth from the Sun? Is this effect cyclical? If so, what period occurs before the cycle of ice age-warm age-ice age repeats? If the Earth periodically cycles through warm and cold climate extremes, what can humans do to moderate the changes that occur?

Sometimes I may use sarcasm and other "word salad" tricks to try to make a subtle point, especially if the point is controversial, like the alleged anthropomorphic causes of global climate change: excessive CO₂ emissions from burning fossil-based fuels such as coal, oil, and natural gas. I noticed from the CO₂ levels detected over Hawaii during the 20th century that the levels were monotonically increasing. The concentration is very low, so any steady increase in concentration is probably caused by human activity. But that does not mean the correlation between CO₂ levels in the atmosphere and the climate of Earth have a causal relationship. I fear it's much more complicated than that.

Last time I looked, the oceans of the world have been around for a few billion years. During that time, everything that ever lived in the ocean died and eventually fell to the bottom, where tremendous forces turned formerly living tissue into a carboniferous soup that eventually became fossil fuel for humans to discover and use. This process of turning the soup back into fuel even occurred also on land as species died, continental plates shifted and buckled, and oceans levels rose to cover the land, before receding to their present levels. We have some fossil evidence that this occurred, yet AFAIK no one knows exactly when or how many times it has occurred. I think it continues to this day, that there is a huge quantity of "fossil fuel" sitting deep under the oceans just waiting for technology to catch up and tap some.

As for ocean shipping... not much has changed over the past few thousand years. Ships should be efficient since they float virtually without friction on water. It is only because of their draft, requiring water to be pushed aside in order to make head-way, that tremendous amounts of power and energy are required to move them around the world. The amount of energy required of course depends on how fast the ship moves from port to port. Sure, heavy seas will require more energy than calm seas, but the difference could be accommodated by NOT using Archimedes Principle to float ships. Instead, use hydrofoils to lift the ship ABOVE the water and just push air out of the way instead of pushing water.

I realize that it would be quite a feat to lift a filled tanker, or a fully-loaded containerized ship, out of the water high enough with hydrofoils for skipping over most of the water under the ship. The main problems that come to mind are speed and size: you need enough "lift" from the hydrofoil to get the ship above the water, and enough speed through the water to create the lift. And you better have clear sea lanes because this sucker is gonna be hard to stop once it gets moving. Once the ship's cargo hull is above the water, it should be smooth, low-energy, "sailing" after that. This type of ship would use very large electric fans for propulsion, with perhaps an underwater screw or two for harbor maneuvering related to docking and un-docking.

One of the main reasons we have nuclear-powered submarines is the need to remain underwater and out of sight of the enemy for long periods of times while underway, not just "parked" somewhere. The subs still need food for the crews, and this requires surface operations. Also, the inertial navigation systems need to be updated periodically by GPS satellites and that requires rising to at least periscope depth. There are relatively few ports where the USA feels both safe and welcome with its nuclear-powered ships, but perhaps a nuclear-powered ship, or several, could be used as "at sea" battery chargers or as a battery exchange service for commercial ships. Many possibilities are available if there is money and desire to be more competitive. Maybe use some oil platforms at sea to store charged-up batteries ready for swap. These platforms could even store the containers that would be lifted aboard the battery-electric vessel to re-supply it with food, fresh water, and perhaps fresh linens or laundry.

I have been invited to visit
Sandia's Z machine.

Good for you. It wasn't offered, and we didn't have time for, a tour when my boss and I visited Sandia National Laboratories (SNL) through the auspices of the Defense Threat Reduction Agency (DTRA). I don't think they had a Z-anything up and running while we were there anyway. So, if allowed, please take some spiffy photographs and upload the pictures here.

I hope your visit goes better than mine: the people we met seemed (to me) to be embarrassed that a tiny private company in Dayton, OH was reviving and successfully using a GaAs PCSS that SNL had abandoned in the previous century. They asked a lot of questions, and we visited some of their labs, but SNL refused our offer to provide them with some of our prototype samples. Perhaps they wanted to make their own, since we fully revealed in the open literature how we did it. I think I saw a strong "Not Invented Here" attitude when we explained what we did and how we did it. One fellow even flatly denied that our device could possibly work. Well, that was his "understanding" and not factual. It does work and we presented photographic evidence taken by our sub-contractor in California. This trip, and SNL's report to DTRA, may have been what led to our fast-track contract to develop more prototypes to be used in modular, scalable, EMP simulators. DTRA seemed to lose all interest after we fulfilled that contract. A few years later UES decided they didn't need a particle accelerator or an engineer to run one. So I was "retired" in December 2014 at age 70.

The "heads up" that DTRA gave them probably revived their interest, but that was not my problem. I enjoyed our visit and had the opportunity to meet some of the brightest people we have to act as caretakers for our nuclear weapons stockpile and designers of future weapons. SNL shares real estate with the Air Force Weapons Laboratory in Albuquerque, NM which is responsible for the development of directed-energy weapons.

If you are up to visiting some of our National Laboratories, I can highly recommend Oak Ridge (ORNL) located near Knoxville, TN. Be sure to get on the tour for the Spallation Neutron Source. This is a truly impressive work of engineering with beam-time reservations available to the public. So start saving now for beam time, and cozy up to a large university with DoD conracts for financing. Maybe submit an unsolicited proposal and ask for Government funding.

The real question is did you tell your grandchildren

Of course I didn't tell my grandchildren. And I didn't read those horrible Grimm's Fairy Tales to my children either. Each generation does as it damn well pleases, learning nothing from the past. My generation may have made a mess of things, but it is the responsibility of YOUR generation to fix it... but I doubt that you can. Doesn't mean you shouldn't try. Let the human race go out fighting and screaming to the very end, never giving up, never reaching beyond the Moon, never mattering at all as far as the Universe is concerned. Or not. It's up to you, so let's get on with it. It is beginning to look like I am not going to live forever, with or without the help of Jesus or advanced AI. If that turns out to be wrong, I promise to come back and haunt all the slackers who gave up too soon.

 

[kellys_eye]

It seems really stupid to me to "waste" them by simply burning fossil fuels, only for the energy stored in them long ago by our Sun through photosynthesis in plants consumed as food by all living organisms in the food chain.

Oil is said to be abiotic(?) and we've not explored or mined so much as a minuscule fraction of the earths resources. Oil is the second most abundant liquid on this planet after water. If we can get over the ridiculous assumption that using such resources is detrimental to all and sundry we could have a much better planet.

a means to dissipate the heat waste produced when using any source of energy

Why? With an approximate irradiance of 1kW per square meter reaching the earths surface from the sun it would be speculative in the extreme to claim that our addition to that is any more than a fraction of a percentage point. You can't eliminate heat anyway.

Battery technology is in the Dark Ages compared to internal combustion (or even external combustion) technology. It is VERY difficult to meet the energy density of fossil fuels without resorting to non-chemical means

In terms of energy density there hasn't been much improvement for decades and any 'improvement' we've seen is usually in ignorance of the environmental destruction required to deliver the battery systems in the first instance.

I noticed from the CO2 levels detected over Hawaii during the 20th century that the levels were monotonically increasing. The concentration is very low, so any steady increase in concentration is probably caused by human activity.

Industrial activity hasn't been on a linear increase - ever - so the increase we see must be caused by natural (at least something OTHER than man) events. Co-incidentally, Hawaii seems to be quite well associated with volcanism so why they chose that place to do the measuring seems to be a bit suspect to me.

Mankind's progress, socially, medically, scientifically, environmentally, financially etc has been predicated on CHEAP and ABUNDANT energy. It is notable that the current practises of 'Green Energy' and the likes of EV's etc are causing HUGE financial constraints to ordinary people whilst the grifters who promote such technologies (and complain about our CO2 production) carry on regardless and get richer at our expense.

I have yet to see or hear any politician PROVE the existence of 'Green Jobs' that are supposed to be coming in the face fo this Green Revolution - all I've seen or heard of are redundancies and offshoring of manufacturing to countries that don't have such stupid energy policies as we in the West are made to endure.

There is too much emphasis and expense on delivering 'theoretical' solutions to problems when the actualities of the real world make such 'solutions' something that only the future MIGHT bring - not something we actually HAVE and CAN use.

When batteries ARE cost-effective, ARE efficient, ARE compact THEN let's make the change. Until such a time we MUST use the cheapest and most abundant energy we can access.

 

[Delta Prime]

I like what both of you are talking about but some parts, not so much.
You bunched everything up, so I can't like the portions of your statements.I'd have to like the whole thing.

 

[kellys_eye]

I'd have to like the whole thing.

Summary: fears of man made global warming, CO2 as a pollutant, ending of fossil fuels and climate Armageddon are all BS.

 

[hevans1944]

I like what both of you are talking about but some parts, not so much.
You bunched everything up, so I can't like the portions of your statements.I'd have to like the whole thing.

Well, Grasshopper, I am glad you like what @kellys_eye and, perhaps, I have been saying. He appears to have his head screwed on tight, and I like to think that I usually do, too. We disagree in the details. But, please, take the time to read everything. You can use the quoting feature of this forum in your comments to select the things you agree or disagree with and talk about whatever you want.

I believe (without proof one way or the other) that there is no such thing as human-caused (anthropogenic) global climate change. Climate change is REAL and it has been going on for billions of years without human intervention. The last ice age may have been one extreme of Earth's climate, and the current global warming may turn out to be another extreme. So what? We have to learn to live with it or simply perish like the dinosaurs did after encountering their mass extinction event.

BTW, I sometimes get "anthropomorphic" mixed up with "anthropogenic" so please don't carp about it. Y'all knows whut ah mean. Global climate change is NOT our fault. It is a naturally occurring cycle that helps to shape the Earth, although that may or may not be the Creators intent. I lost my hot-line to God during the move from Dayton, Ohio to paradise in Florida, so you are gonna have to figure out what purpose (if any) Earth's climate change has in the overall scheme of reality.

Most people do not have ANY comprehension about how BIG the Earth is. Or the Universe.

You can't eliminate heat anyway.

Didn't say you have to eliminate heat. With increasing energy use comes increasing "waste" heat. If (someday) someone find enough usable energy to move the Sun (and its gravitational-attached planets and stuff), there will no-doubt be some excess heat to dissipate during the journey. This subject has been extensively discussed in the science fiction literature, so I can offer no further insights at this time. My (rectal extraction again) time estimate for when the human race might have the will and the means to move its home system willfully among the stars is a million years or so.

we've not explored or mined so much as a minuscule fraction of the earths resources

Correct. We haven't even drilled through the Earth's mantle, much less thought about the wealth of material between the surface and the core. Has anyone even thought of using the Earth's magnetic field to rotate the spin axis angle with respect to the ecliptic? That would certainly have an effect on global climate.

Who knows what sort of interstellar gasses or left-overs of creation the solar system encounters on this journey among the stars? What effect does the interstellar environment have on the amount of energy intercepted by the Earth from the Sun? Is this effect cyclical? If so, what period occurs before the cycle of ice age-warm age-ice age repeats? If the Earth periodically cycles through warm and cold climate extremes, what can humans do to moderate the changes that occur?

Those are some thoughts to ponder. I have no answers yet. Perhaps further exploration into interstellar space will reveal more.

 

[kellys_eye]

This subject has been extensively discussed in the science fiction literature

I'm an avid fan of sci fi (have you read Ian M Banks?) and strongly believe that given the resources and motivation that man can overcome 'any' fate bestowed him. Most scifi deals with a future where politics is less of an intrusion in the lives of ordinary people, in fact IMB writes about a future where AI assists and protects humans in a society of zero need, zero greed, zero disease and infinite prospects. That's a society I can get with....

 

[Martaine2005]

And…

I think both of you should take a "bow" then perhaps the chips on your shoulders will fall off.

on that note…..
What about the loop antenna the OP enquired about?

Martin

 

[Delta Prime]

And…

on that note…..
What about the loop antenna the OP enquired about?

Martin

As stated before the op and I are in conflict. We are both bounty hunters. I'll tell you a secret Mr Martin.

There are also new components called kinetic inductors that leverage graphene technology and have now been developed,whose principles do not perform as the classical inductance because it is the highest inductance-density material ever created

You made me spill the beans...
Efficiency of charging in an electromagnetic field just went up an order magnitude!
Along with my bank account!!