Super Capacitors

[Doug Lord]

Go 500 miles (for $9)and recharge in 5 minutes!? This is part of what is claimed for this new technology about to make its debut in the Zenn electric car. Lighter by several times than the lightest existing batteries etc,etc..
http://sustainablog.org/2006/09/25/will-the-eestor-revolutionize-the-electric-car/
http://cleantechnica.com/2008/04/12/zenn-electric-cars-to-steal-some-thunder/
---------
Anybody know any more?

[Jimbo1490]

Doug,

When I saw the first 1f (albeit only 5v) capacitor that was the size of a dime about 15 years ago, I wondered when caps would get this good. So here we are! Trouble with any electric cars is not the cars, per se, but the fact that the electric grid in the US is hopelessly outdated and just can't deal with more capacity (no pun intended). So if widely adopted, these would place strain on that grid that it just can't handle.

On the plus side, capacitors suffer none of the horrid charging losses that even the best batteries exhibit, so unlike battery powered electrics, cap powered electrics do not represent a net loss in efficiency. Another cool thing about caps is that once charged, they stay charged until discharged; even sitting for years.

There is still the issue of what powers the grid, which right now is still mostly fossil fuels.

Jimbo

[CDK]

Two conducting surfaces, separated by an insulator, form a capacitor. The capacity is determined by the surface area and the distance between the surfaces.
For the insulator all kinds of materials have been used, like glass, paper, mica and polyester film. A major breakthrough was the use of aluminium oxide in a liquid filled tube: the electrolytic capacitor was born! That was around 1935.
This principle is still used for all kinds of electrolytic caps, first with aluminium foil and electrolyte soaked paper, later with more exotic metals like tantalum and vacuum deposited conductors on an oxide surface.

One common characteristic is that the devices are unipolar: reversing the polarity destroys the oxide layer and causes a short circuit. Another is
the fact that the maximum working voltage is very low because the oxide layer is very thin. For the gold caps or super caps, now used in equipment to retain data during a power interruption the working voltage is limited to just a few volts, because the technology is the same as is used in MOS-FET's, only with even thinner oxide layers.

But how much energy can a super-cap store?
By definition, a capacitor of 1 Farad can supply 1 Amp for 1 second. Not very spectacular if you compare it with a small car battery that can deliver 1 Amp for 50 hours ( 180000 seconds). You would need a 180.000 Farad capacitor to do that, provided that it could handle 12 volts. If a 1 F super-cap has the size of a small coin, 180.000 pieces wired together will take at least the volume of the car battery.

You could argue that super-caps could be produced that have a much higher capacity, say 1000 Farads, so you only need 18 pieces to imitate the car battery. True, but for practical use we need a battery that can deliver not 1 Amp for 50 hours, but 50 Amps for 1 hour, plus 400 Amps for half a minute to start the engine. Such currents require massive conductors, like copper bars ending in the kind of terminal used for car batteries.
Only if the super-cap could be cooled to near 0 degrees Kelvin and kept there indefinitely it could be significantly smaller than Ni-Mh, Li-ion or lead-acid batteries. (Disregarding the 1000+ lbs equipment to reach and maintain super-conductivity of course)

To construct a power source for vehicle use, the 50 Ah example is of course insufficient. Instead of 50x12 = 600 Watts, we need at least 50 times more storage capacity for a modest city vehicle, 200 times more if it must be competitive with present day gas or diesel vehicles.
That is a lot of electrical energy in a very small space, requiring all sorts of safety devices to keep it from turning into a power bomb in case of a less-than-a-micron-thick insulator brake-down.

One last remark: that capacitors have 100% efficiency only holds true for a theoretical case where isolation is 100% non-conductive and conductors have 0 resistance. In real life however, nothing is perfect. The charge will slowly leak away because there are always impurities in such an enormous insulator surface and the internal resistance of the conductor grid will turn part of the electrical energy into heat.
The only thing positive about super-caps is that there are only electrons moving around, no atoms, so the life expectancy exceeds that of any form of chemical energy storage.

[Fanie]

Go 500 miles (for $9)and recharge in 5 minutes!?
Forget it !!

Super capacitors are not even close yet to provide the energy supply (even small) batteries are capable of. Although new caps have impressive farrad ratings, the amount of energy stored is not good enough for propulsion.

Unless they meant you drive 500 miles to pay $9 for a cap you can charge to rated voltage. Whole different meaning :D


There are new batteries currently being developed they claim can charge in 90 seconds to full capacity, and although it may well be possible, I haven't seen any of them. The expected life span (charges before replace) is also a factor in batteries.

We are still looking for the ideal energy source, while some near ideal ones exist (radio active source, hydrogen gas) the deveplopment of these have not yet been commercialized and will not happen until they can find a way of safely work with /dispose of the sources, or find a way to rip you for a liter of water.

[ancient kayaker]

These things are what matter when it comes to electrical power storage for autos:

KWH/lb
KWH/$
KWH/cu ft
overall efficiency at high currents
charge/recharge cycles and durability
memory effects
charge retention

As far as I know, lithium ion batteries are the current leader in most of these areas and are rapidly catching up in areas where they are deficient such as cost. Not sure about safety aspects: storing that much energy in a small space is unlikely ever to be completely safe, no more than a tankful of gas when the tank splits. There are several lithium ion technologies, some better than others.

Concerning super-capacitors, my understanding is that they are currently able to power a toy car for a minute or so if that.

And then there's fuel cells.

I look forward to be proven wrong!

[Fanie]

The Ancient meets the future :D

Batteries are usually designed for a specific type of application, so in most cases I cannot replace the two 105AH SLA batteries for my 24V trolling motor. Well, I can but the financial impact would be considerable, and then also, would it really be worth my while to do so ?

It is always so that if something really good and affordable becomes available, it replaces the old stuff, and that becomes the new 'standard'.

[Doug Lord]

So if you guys are right the Zenn car story is a complete ripoff. We'll see.
Personally, I hope you are dead wrong-well, not the "dead" part!
----------
Just found this-seems like the eestor(Zenn) system would really be terrific-if it's really possible. But this seems encouraging as well:
http://www.supercapacitors.org/

[mark775]

They have been having amazing press releases for years. It´s how this type of company obtains venture capitol. Believe it when you see it.

[FAST FRED]

So if you guys are right the Zenn car story is a complete ripoff. We'll see.
Personally, I hope you are dead wrong-well, not the "dead" part!

If you like "stories" look up Ballard and fuel cells, million$ and million$ in research bucks , for NOTHING.

so far

FF

[Fanie]

Fast Fred,

There are two problems with caps. The first is the voltage drops as you discharge it, unlike a battery that tends to maintain it's voltage. Using a cap then requires a higher voltage that gets regulated to your working voltage.

The second problem is the size. A 1 farrad cap that can charge safely to ie 24 V is a sizeable item. To be able to run a trolling motor for say 10 mins off a cap, the size required will probably be much bigger than the boat if at all possible for that long a time at some current.

Capacitors lend themself excellent to supply high currents for very short periods of time, like in stud spot welders, but as a power source they are not suitable.

As for research, there are too many who gets the money and use it to live off and well too, while no real research is done. We have the same here. Some guys have really rediculous ideas that will never work, but it seems a slick tongue gets them the green.

[ancient kayaker]

Fanie: valid point about voltage drop.

I hope my pessimism is wrong too, so OK, I did the math:

9 min charge, lets say it can absorb the entire 200A/220V available from a house service and everything else in the house is turned off. (assumptions: ability to handle the energy level, 100% charging efficiency)

That makes max 6.6kWH energy available.

500 km range? Lets assume 50 klick speed, so it will have to drive 10 hours at 0.66 kW which is about 1 hp. (implications and/or assumptions: 100% efficiency, single occupant, prone position bike, fully-enclosed streamlined shell, extremely lightweight). Hardly suitable for shopping or going to work.

Substitute some sensible efficiency, weight and drag values that could translate into a useable vehicle and you may get 30 km. Actually, even that would be an impressive achievement for a 9 min charge. Reduce my assumption on charge rate to something that standard house wiring can handle and insist on minimum range of 100 km and you're looking at a charge time around 20 hours, but that could be reduced to 5 hours with a suitable electrical service.

I think supercapacitors of this kind may have a place in future transportation through their contribution to overall system efficiency, by levelling power variations, easing surge demands on the battery so the battery technology can be optimized for capacity and efficiency.

[ancient kayaker]

So if you guys are right the Zenn car story is a complete ripoff. We'll see.
Personally, I hope you are dead wrong-well, not the "dead" part!

If you like "stories" look up Ballard and fuel cells, million$ and million$ in research bucks , for NOTHING.

so far

FF

Not quite nothing but certainly less than we all anticipated from all the hoopla back in the 90's. I understand that Ballard is still working actively with Ford, maybe Chrysler too.

Two problems with the hydrogen fuel cell is fuel distribution and fuel handling safety. Some would say that, with modern attitudes to safety gaining acceptance for the gasoline engine would have faced similar challenges. The people best positioned to distribute hydrogen fuel is the oil industry ...

[Ilan Voyager]

As a very long time ago I ceased to believe in Santa Claus, I'll wait to see usable cap/batteries without shortcomings. Technically, it's very doubtful that works in a practical way.
EEStor announces that for mid-2009...we'll see.

[marshmat]

EEStor actually announcing something? Well, that'll be the day.... lol

Their notorious secrecy aside, they may be on to something. There was a rumour circulating a few years ago that EEStor was doing some experiments with barium titanate in the electrolyte; it's been documented that BaTiO3 can have a permittivity of 1200 or more if you grow the crystals just right. That's one hell of a dielectric.

Ballard.... well, thats another story. I think the production challenges proved to be somewhat greater than they had expected. They never did manage to get away from the need for a platinum catalyst adjacent to the PEM itself. There's lots of work going on right now about that issue, probably the single biggest reason why the cost of fuel cells is so high, but the current research is being done with somewhat less media fanfare, and minus the stock market woes that plagued Ballard.

I've worked on the design and construction of two cars that have crossed continents at 80-100 km/h on about a kilowatt. It's quite possible, but you need to give up on some conventional notions of what a car should look like.

The claim of 500 km range on a $9, five minute charge- that sounds more like a 3rd-party blogger getting a bit exuberant. A $9 charge is about 82 kWh at current prices of about 11 c/kWh (incl. transmission, etc. fees) in North America. That's reasonable- 16.4 kW or 22 hp for 5 hours to drive a small car 100 km/h. (Again, neglecting inefficiencies for the purposes of simple illustration for now.)

But to transfer 82 kWh in 5 minutes would require a 984 kW supply- ie, nearly a thousand amps at 1 kV. That's not something you would want in your garage!

[Fanie]

Hang or Matt, a capacitor is formed when two surfaces are oposite one another, the capacity is determined by the surface area and the distance between the plates. Dielectric and quality of insulation between plates determines the ESR rating, which is the impedence of the device. The lower the ESR, the better the cap, but you are still haunted by the surface area restriction and distance between plates for a certain voltage.

Cap charge is static, but you can only charge the cap to a certain voltage. Any load will cause a drop in the voltage. You cannot have a cap, like a battery, 'store' energy that will break the charge down over a period of time at a constant supply.

I have heard of barium titanite before, but I doubt the association was with capacitors, or it was something similar to do with hydrofusion which in my humble opinion is more of a future fuel than anything else.

If they do succeed to cross the capacitor with a battery and specially growed crystals we are back to a battery or cell and not a capacitor.

Question is, while everyone complains about fuel cell and battery prices, I doubt these cap-bat cells are going to be cheaper. Similar to solar, growing crystals is a slow process and remains expensive hence the shortage on solar panel cells and their still bloody expensive and unefficient.

My opinion if there was something that exciting someone would have started it in the 1960's already :D

[marshmat]

Hang or Matt, a capacitor is formed when two surfaces are oposite one another, the capacity is determined by the surface area and the distance between the plates.
True, if the medium separating the plates has dielectric constant ε=1.
When the dielectric constant is larger than 1, the field E confined between the plates (and thus the potential difference, V) is reduced by a factor 1/ε, and thus the capacitance C=Q/V is increased by a factor of ε. This is one secret of how to beef up a capacitor: Increase the dielectric constant of the insulating material. Hence the barium titanate experiments that were being done a few years ago; I don't know if that avenue of research went anywhere useful in the end.

The other trick to beefing up a capacitor is to decrease the spacing between the plates while increasing their effective area. This is where modern nanotechnology comes in- processes and techniques we simply didn't have until the last few years.

I suspect that what EEStor has done is a combination of the above techniques. But they let so little information out that I don't know for sure how their ultracapacitor is built.

Cap charge is static, but you can only charge the cap to a certain voltage. Any load will cause a drop in the voltage. You cannot have a cap, like a battery, 'store' energy that will break the charge down over a period of time at a constant supply True. A capacitor's voltage-time discharge curve cannot be constant, very much unlike that of a battery. Making effective use of ultracapacitors for storing significant amounts of energy would require significant advances in DC voltage regulation.

[Fanie]

Lets wait and see what they come out with. I'm curious as to how much power they are going to supply and over what time. At 9$ one could maybe buy a few and cruise all day long :D

[Doug Lord]

Matt, do you think it is possible that eestor actually have made a significant breakthrough? Maybe the secrecy is part of their reaction to having done something so significant(or insignificant for that matter)?
I imagine there would be a herd of thieves after them IF they had succeeded....

[marshmat]

I think they're just being really, really careful to make sure their device is performing the way they want it to, and that their patents are in line, before they let anything slip. Many a tech firm has been killed when information became public too early, the media pounced, and a frenzy of stock activity, over-inflated 3rd-party predictions, and general chaos drove the stock sky high and then straight into the ground.

The engineering challenges that would have to be overcome to get a viable ultracapacitor are now fairly well-defined, and I would expect anyone trying to work through them would be very careful about what information got out- due not only to potential competitors, but also because of the risk of the firm being bought up and hidden away by larger companies who would have something to lose if it were to work. One need only look at how closely Chevron (through Cobasys) guards the patent on the NiMH battery technology to see why EEStor would be a bit paranoid.

[CDK]

A datasheet of an existing Ultracapacitor can be found on the Maxwell website, http://www.maxwell.com/ultracapacitors/products/modules bpak0020-15v.asp

This is a real, existing product, more or less comparable with a LA battery: it has 6 cells and up to 15 VDC working voltage. With this advanced technology, Maxwell states the power to weight ratio as 3.25 Watt-hours /kg. A small car battery rated at 50 AH packs 600 watt-hours, so to reach the same storage capacity with these Ultracaps, approx. 20 kg. of these will be required.
The car battery is still the winner, with approx. 12 kg, but the gap is less than I would have guessed.

Maxwell is not very confident that the Ultracap will perform as well as the data-sheet promises: no warranties of any kind, not suitable for life support devices or critcal systems etc. But the target is set at 500.000 cycles, exceeding that of the best rechargeable batteries with at least 2 decimals. And the cycle test is done at only half the working voltage and with constant charge/discharge current.
Moreover, for the type BPAK0052 P015 B02, clearly a commercial product, a leakage current of 50 mA is considered acceptable. Translated into plain English this means that the capacitor must be under continuous charge, otherwise it will be empty when needed.

Summary: an interesting development, but far from perfect. And a very negative aspect of this technology is that this product is of the electrolytic type, so there is a liquid inside that may leak out or evaporate if the seal is less than perfect, if the temperature limits are exceeded or a cell is charged above 2.5 volts.

If the secret EEstor capacitor is twice as good as this one, it is still a lousy power source for a vehicle; it must be 10 times as good and even
then there is the problem of the unstable output voltage requiring lots of electronics before it can be used to power an electric motor.

[robherc]

hmmm.... Just did some research using the links posted earlier in this thread. Here's some info (claims) from a patent EESTOR recently aquired. You can read the ultracapacitors.org writeup on it here: http://www.ultracapacitors.org/ultracapacitors.org-blog/eestor-issued-new-patent-on-the-eesu.html

Unfortunately, nobody knows of any working prototype of this technology :(
Anywise, I'll attach a chart that they included in their patent documentation, I LOVE how american inventors have taken to making statements of "facts" related to their patents' capabilities when no working protos exist...rofl!

[Doug Lord]

Thanks for all the input! Very exciting to contemplate that MAYBE somebody has a real breakthru. Makes me want to take another look at doing a small electric cat or tri. What if it is really true? Imagine the possibilities...

[marshmat]

Here's the link to the entire patent, if anyone's interested:
http://www.pat2pdf.org/patents/pat7466536.pdf
It was just issued on Dec. 19.

That clarifies a few things. Firstly, the claim of 52.22 kWh energy storage: This appears to be a calculated value, given that the capacitance of the device is claimed as 30.693 F (sounds like the right ballpark for an ultracapacitor this size, if rather more precise than manufacturing tolerances would allow) and its maximum operating voltage is 3500 V (again, reasonable in theory, but that introduces some practical problems.)

The patent also clarifies how the device is built and how it works. Unfortunately, it is written in engineers' legalese; if you're familiar with the language, though, the patent answers a lot of questions. To summarize, it is a lightweight, high-voltage, high-permittivity parallel plate capacitor. (They claim a permittivity of 19,861 for their composition-modified barium titanate dielectric- absolutely astounding, if they can do it reliably.)

A promising technology, yes. Car applications- for sure, especially for capturing regenerative-braking energy, or as a short-term buffer for electric-drive vehicles with a small gas generator (ie, Chevy Volt et al). To use it as the sole energy storage device may prove a bit more challenging, although not impossible; an efficient and economical way of safely regulating a source that varies from a few hundred to 3500 V DC will be necessary. It may also see use as a buffer system for wind/solar installations, or as a backup supply in houses, businesses, etc.

[ancient kayaker]

The S-C will serve as a short term buffer in conjunction with a battery and reduce the design requirements of the battery which should improve performance and costs in that area.

There a 1.5F, 3V capacitor available back when I took an interest in capacitor performance, around 1979, but that was a tiny thing (1" dia) mounted on a circuit board. It was a ceramic capacitor and therefore bipolar.

The increase in capacitance is not much but the S-C's much greater size and weight, but the improvement in the operating voltage is dramatic and that increases stored energy in proportion to the square. An electrolytic capacitor stack back in the 70's with similar capacity would have weighed around 2.5 tonnes.

[CDK]

The patent text describes an inexpensive way to manufacture multi-layer ceramic capacitors. These devices are not new, they exist several decades already, and so does barium titanate, which sounds like a salt but in fact is a complex oxide.

The 3.5 Kv working voltage is unusually high for this type of capacitor, but that is probably because the industry does not need caps for such voltages. With lower voltage, i.e. 50 volts the devices are cheaper and smaller.

Practical use as power storage device is something I cannot judge: as far as I know there are no reliable low cost MOSFET's that could be used for a switching power supply in the 10 Kilowatt range. But given time, that may change. Planning this technology for a soon to be released electric car seems a bit premature to me.

[marshmat]

A MOSFET that can handle tens of kilowatts at 3.5 kV, at a price that would let you put it in a mass-market car.... that would be impressive indeed.

The ZENN car is already on sale in a few places, but is not street legal in many jurisdictions because it can't keep up with 60+ km/h traffic. Perhaps they have something in their R&D lab that will be able to control the EEStor capacitor....

As I've mentioned before, 3rd-party bloggers with lots of interest but somewhat less technical knowledge have been blowing things out of proportion somewhat. Charging the EEStor capacitor in 5 minutes may be theoretically possible, but no sane electrician is going to install the requisite thousand-kilowatt, 3.5 kV power feed, transformer and charge controller in a homeowner's garage.

[Boston]

dam interesting thread kids

[robherc]

Actually, looking at their chart from the patent, it would be a VERY viable energy source (with no batteries) for an elec. car, as long as you could regulate the voltage. If you believe the claims in the chart it's lighter, smaller, faster charging, and has a slower energy dissipation rate than any curr. battery technology...though the cost would most likely be astronomical at the moment.

I also ran a quick equation for their (3-6 minute) charging time, it worked out to 522.2-1044.4KW @ 3.5KV ... I'll PASS on having that monstrous powerline anywhere on my property....anyone happen to know the flowrate of the bare high-tension treble wires?

Also, won't 3.5KV bridge about a foot (.28M) of air at 1 atmosphere & 70% humidity??? doesn't sound like a very safe thing to have in your car where "backyard mechanics" would be getting electrocuted left & right by it!

[marshmat]

anyone happen to know the flowrate of the bare high-tension treble wires?
A typical transmission line in the 115 to 350 kV range would likely have a summer thermal ampacity rating (ie, the maximum you can put through it on a hot day without overheating the lines) somewhere in the range of 800 to 4000 amperes. Depends on the particular conductors being used, of course.

Mechanics (and firefighters) are already somewhat scared of the batteries in current hybrid cars, and rightly so. A whole new level of training is required for anyone planning to work on high-power electrics.

[robherc]

OK, so if I'm doing my math right, you're saying that (on a hot day) these high-tension lines can carry between 92MW-1400MW
In essence, this tells me that our current power grid has room for, say, 85K-1M of these capacitors per state...assuming all other power usage was stopped completely...and for an "average" car with a respectable range of at least 300mi, we're talking about what, 4 capacitors/car? Obviously, our power grid would need a LOT of work before eny form of electric car for the masses is possible!!

LOL, for some reason I'm having flashbacks to 2003....whole eastern 1/3 of the US was without power because of an overheated high-tension line in OH starting a "cascade effect" and blowing out substations across the map!

[marshmat]

There are of course plenty of other factors involved, robherc, but yes, you've hit on the big problem that we would encounter if we start deploying electric cars on a wide scale. Significant improvements to the generation and transmission grid would be necessary, otherwise we'd end up with widespread blackouts.

Canada had that blackout too, it spread all through Ontario, New England and most of the Great Lakes states in minutes. Really woke us up to just how fragile the power transmission grid is.

[Doug Lord]

Is it possible that as part of this development some thought has been given to extremely high capacity charging systems/generators -maybe using fuel cells or some other advanced technology? The idea would be to separate this technology from the grid?

[Boston]

we used to leave a live cap on the work bench just to give the folks who couldn't keep there hands off stuff a lesson
shoulda rigged a camera to go off

[robherc]

Boston:
Hmmm...if you're gonna use a 3.5KV, 52.2KWH cap, you might want to put a disclaimer on your electrocution bench...but the smoking body would prob. keep others away!...rofl

Doug:
The problem with fuel cells is that they ARE, in effect, batteries. We don't simply harvest Hydrogen from the atmosphere/mines/whatever in any significant quantities...the only way to come by enough hydrogen to power the automotive industry is to MAKE it through electrolysis breakdown of water, so you still have to generate the electricity to make the hydrogen some other way. Long description above to say: Hydrogen fuel cells may be a great way to TRANSPORT energy, but the grid still needs to be upgraded so it can generate/handle the amounts of energy required by these electric vehicles. To say "the world isn't ready," in this case, is all-too-practical an answer!

[Boston]

no we didn't use a very big one, but after who knows how many people being told not to touch anything ended up standing over some broken something on the floor looking stupid, we decided a nice inviting juicy blue thing placed right in the front of all the other stuff might be in order.
worked every time.
hey we told ya not to touch anything
course that was way back in school and we were kinda apt to play a few "harmless" practical jokes from time to time
B

[ancient kayaker]

We used to leave a Tantalum capacitor connected backwards to a DC source if we wanted to teach terminally curious folk a lesson. They exploded with a mighty bang with tiny bits of confetti drifting down from the ceiling and the most awful stink that you could actually taste. Didn't hurt, but it nailed all the other 4 senses!

I accidentally subjected myself to this trick as a young graduate when I hooked up a bank of big ones to a 60V 50A DC supply and turned it on. I was deaf for most of the day!

[marshmat]

Clever ideas Boston & AK..... might have to try that in our lab if people start stealing stuff again....

[Willallison]

As a very long time ago I ceased to believe in Santa Claus....


Sorry to leap way back to page 1... but I couldn't help but take exception to what can only be a typo from IV.....;)

Bloody good thread BTW...

[Boston]

something inviting about a big blue thing "obviously" not attached to anything that screams pick me up play with me louder than a prom date
let us know how it works out
B

[sailor2]

This is a real, existing product, more or less comparable with a LA battery: it has 6 cells and up to 15 VDC working voltage. With this advanced technology, Maxwell states the power to weight ratio as 3.25 Watt-hours /kg. A small car battery rated at 50 AH packs 600 watt-hours, so to reach the same storage capacity with these Ultracaps, approx. 20 kg. of these will be required.
The car battery is still the winner, with approx. 12 kg, but the gap is less than I would have guessed. How about recalculating that claim.
3.25 Wh/kg = 65Wh/20kg, a far cry from 600Wh/kg a standard battery is capable of.
In other words you need more like 200 kg of those to match 12 kg of battery.

Same problem with post #3

[Fanie]

Clever ideas Boston & AK..... might have to try that in our lab if people start stealing stuff again....

Mind the big caps, they can be dangerous. I've heard of incidents where large electrolytics exploded with unfortunate results.

I once supplied a customer with a batch of units where there are 3300uF 25V caps in... one cap was the wrong way round in one PCB. I tried to find out what happened when it was switched on, but nobody that was there wants to talk. They probably all needed a change of clothes :D

Mind the eyes folks. Even the glass ones are bloody expensive I've heard.

[CDK]

Sailor2 I apologize for that stupid mistake. I sometimes try to do several things at the same time with this kind of results.
The Maxwell datasheet really states 3,25 Wh/kg and under applications "portable power tools". What kind of tools?

[Boston]

your absolutely right Fanie
although I have never seen one explode Ive sure seen one zap someone and its no joke
well
it is if your not the fool jumping round hollering
we just used little battery sized ones that were easy to get a finger across
put it right in front of the sign on the bench that says "do not touch"

[marshmat]

How about recalculating that claim.
3.25 Wh/kg = 65Wh/20kg, a far cry from 600Wh/kg a standard battery is capable of.
In other words you need more like 200 kg of those to match 12 kg of battery.

Same problem with post #3

Sailor2,

If you have a battery that gives you 600 Wh/kg I would love to hear about it.

A good flat plate lead-acid battery can hold about 35 Wh/kg; some of the fancy spiral-cell ones are closing in on 50. The very best Li-poly cells I've worked with (a Saehan/Enertech product) were in the ballpark of 150 Wh/kg or more; trying to push Li-poly to 200 is not impossible, but very difficult and expensive.

[sailor2]

Sailor2,
If you have a battery that gives you 600 Wh/kg I would love to hear about it.
I don't of course. At least that typo was already hinted at on the same post in the following line.
So yes, it did back fire at me, but the initial typo still lead many to draw wrong conclusions about the capasitors potentials and therefore needed to be corrected. Batteries are still much better on stored energy/weight ratio, currently by at least 10 times, than best capasitors which was the point. And I don't see that changing anytime in near future, if even in distant one.

[Boston]

ok
Ive debated bringing this up as Ive not patented it yet and not sure I even can as the us patent office hates this kind of thing

I dreamed this thing up about ten years ago and just kinda sat on it

I realize half you folks will tell me this wont work and Im not positive it will but at the same time it seems like it should

http://i29.photobucket.com/albums/c262/bostonpyramidbuilder/invention2copy.jpg

its basically a mechanical battery
based on magnetic's

all you need do is hang an conductive coil between the body and the armature and
electricity
reverse the polarity and
a motor

not sure how long it would run but I think it out to work

by the way if any light bulbs ( sorry bad pun ) go off in anyones head remember where you found this thing and cut me in for something
B

ps
it has no practical application in boating

[Boston]

almost forgot
I was thinkin this thing would be more of a semi powered storage gyroscope
its not the power intrinsic to the magnets your actually using but the energy of the rotation of the armature. if it was used in conjunction with a set of solar cells then it could charge the magnets and spin the armature up, the magnets would just keep it there
good rare earth magnets last forever and are dam powerfull for there size but they will die eventually
if you compress the two halves together you get a faster armature speed but you also get more resistance between components
that would kill the magnets
so the solar cells would connect to a matrix of wires in the magnets and a trickle current keep things oriented properly
theory is
or at least what I was hoping is that this would be more efficient than a lead battery
and a little lighter
you could vary the speed and the torque of the armature by compressing the two halves

maybe
assuming it works

well I intended it to be part of a system and since I didnt reveal the whole thing it may have been confusing
the magnetic system on its own will produce a small amount of electricity but at the cost of the magnetism.
but if ceramic magnets are used them a matrix of wires could be installed during the manufacturing process and used by solar cells to keep the magnetic material "charged" oriented properly for essentially ever.
the rpm of the system would be maintained in storage mode by the natural magnetism of the system limited only by the max rpm ( centripetal forces vs material strength )
I wouldn't be trying to increase the magnetic properties of the system components at any time. Just increasing rpm. its the gyroscopic action that does the storing of the electricity and with one moving part on magnetic bearings in a vacuum maintaining friction losses through the use of the magnetic fields
might not be so hard
maybe
as I said
not sure it works

[FAST FRED]

"I think they're just being really, really careful to make sure their device is performing the way they want it to, and that their patents are in line, before they let anything slip."

Why bother ? The Chinese simply get the patent on line and copy what ever they damn please.

FF

[mark775]

Boston, it "seems like this thing should rotate" and your wanting it to rotate don´t make it happen. Debate longer.

[robherc]

Boston, it "seems like this thing should rotate" and your wanting it to rotate don´t make it happen.

Actually, Mark...after reading his second post, I agree with him that, if the device were contained in a vacuum, it could be used as a type of "flywheel on a frictionless bearing" for storing mechanical energy that was input at the spindle. Using the polarity repulsion of the magnets would simply to keep it suspended.
Now, I think he'd have to modify the design a good bit by shrinking the diameter, using North AND South polar repulsion, etc. before he could make it a very useful storage device, but it could be used to store motion energy...similar to those early '90s "magic" floating tops.

[Boston]

it does use north and south
the drawing on the bottom, it should have had a red s on either side of the little spheres that are labeled with just an n on opposite sides
there is an apposing force ( south ) pushing the sphere into the gap in the field created by the like poles ( north )
forgot to label that when I drew it

I didnt really give the thing a lot of thought
seemed like it was just a magnetically powered gyroscope
kinda a dc motor/flywheel without a commutator

[CDK]

I read today that one John Keogh successfully applied for a patent at the Australian patent office. His invention was generally known as 'the wheel'.

[Jimbo1490]

If this was ever a patentable idea, you've started the clock ticking for obtaing said patent upon your first public disclosure of the device.

A comment on the device:

I do not see a mechanism for pole reversal (commutation, alternating current, etc) in this (proposed) device. A motor or generator must have a means by which polarities are flipped during the rotational cycle to be functional. A mechanical switch (commutator) is used in 'universal' motors. Stator poles induce a current in the armature of an induction motor which alternates in opposition to the stator poles. This is what causes an alternating 'difference' in magnetic flux that can either propel the rotor (in a motor) or resist the rotation of the armature (in a generator). What is that mechanism in this device?

Jimbo

[robherc]

If this was ever a patentable idea, you've started the clock ticking for obtaing said patent upon your first public disclosure of the device.
Hmmm...way too late on mine then, as I passed diagrams around to several other students in the school however-many years ago....lol patent would have expired by now anywise ;)


I do not see a mechanism for pole reversal (commutation, alternating current, etc) in this (proposed) device. ... What is that mechanism in this device?

I think he mentioned in his first post that he intended to add a "coil" for power generation & storage...though I would rather lean towards attaching an external generator/motor to the spindle via a clutch. That way you could release the clutch & not suffer drag from the generator when in "storage mode"

[Jimbo1490]

I think he mentioned in his first post that he intended to add a "coil" for power generation & storage...though I would rather lean towards attaching an external generator/motor to the spindle via a clutch. That way you could release the clutch & not suffer drag from the generator when in "storage mode"

No, a coil still does not address the lack of a pole reversal mechanism. That's a separate issue.

Jimbo

[Boston]

think of it as two dipole spheres in a monopole plane

the spheres poles are on the x axis of the cube they lay within

so you do have a mechanical if permanent polar moment

it can be increased by moving the two halves of the cube closer to one another

there is no need for a commutator

the next trick is to keep the magnets from realigning ( wearing out ) which can be done with the solar cells applying a slight dc current to the material in the same way it was when the magnets were manufactured

the coil removes energy
the proximity of the two halves of the cube apply energy
the solar cells keep the thing magnetic

so the sun charges the magnets
the magnets spin round and round creating an oscillating field
the coil in the oscillating field lines has an induced current
the faster the thing spins the more energy is available

sorry it took me so long to hemorrhage a decent explanation I just havent looked at it in ages

[Jimbo1490]

The way I understand the device, the 'rotor' will have no preference for any particular alignment, therefore no emf will be transmitted to the shaft, therefore no current generated, or no rotation induced. The 'cubes' need to switch polarity within the cycle for the thing to work as a motor or generator.

And magnets are not charged with a "slight" DC current. Rather they are charged with a low voltage and a very high current. In other words with a very short coil of only a few turns of rather heavy gauge wire.

Jimbo

[Boston]

hmmm
did I mention the cube and the spheres fields are perpendicular to one another

once a dipole molecule is set in a ceramic matrix it tends to stay put for quite a long time
and given a slight charge when not being called on to do any work it should resist any realignment

as I said not sure if it works just something I dreamed up and sat on till this conversation reminded me of it

[robherc]

Hmmm...no I don't believe the cube will incite spin on the spheres in your setup. It will, however, keep the spheres & their shaft suspended between halves if you switch one of your poles (i.e. N up on spheres, and bottom half of cube...N down on top half of cube). Then you could utilize your design as a frictionless bearing in a vacuum.
If you wanted it to spin, you'd have to align unequal numbers of magnets in concentric rings....or use a non-polar ring magnet...but that's another story altogether.

[Boston]

well thats the standard theory of the magnetic motor
but what if there were a imblanced magnetic field

what I tried to do was create a monopole environment in which to sail a dipole sail
so I connected two with a rod on a pivot and sailed em in circles

I was hoping the south pole would pull the sphere through the field of the cube while the north pole of the sphere pushed

I remember talking to some of the folks at CU about this thing when I first dreamed it up and there was every range of discussion
it may or may not work depends on who you talk to


Roberc
did you ever build one

I must not be explaining it very well cause the polarity of the spheres in the field they are set in would not result in a magnetic bearing like arrangement

[robherc]

Roberc
did you ever build one
Once upon a time...in another (schoolkid) life...

The Prototype:
I took the magnets out of several of the "Science Fair Magnetic Wand" toys available at the time.
3 of them, evenly spaced I put on the spokes of my improvised spindle
5 of them I spaced evenly in the outer ring.

The Experiment:
I had to coax it a little (poor design...high friction & low power), but it did "spin up". It wasn't very efficient, was very poorly built, and spun a bit unevenly (prob. needed to change the spacing of the magnets, and reduce tolerances a LOT). It didn't spin for long, though, as the whole thing quickly tore itself apart...lol, what did you really expect, I was in 7th grade at the time, and had zero funds to work with. Heck, I built most of it out of Elmer's glue & popsicle sticks! :P

[Boston]

my theory is that in a single field it will work but if you use a number of fields to make up the cube you end up with "bumps in the road"

ya I did a lot of that when I was a kid as well
memories
Im thinkin a lot of folks on this forum did

[robherc]

but what if there were a imblanced magnetic field

what I tried to do was create a monopole environment in which to sail a dipole sail
so I connected two with a rod on a pivot and sailed em in circles

I was hoping the south pole would pull the sphere through the field of the cube while the north pole of the sphere pushed

...

I must not be explaining it very well cause the polarity of the spheres in the field they are set in would not result in a magnetic bearing like arrangement
OK, if the poles of your spheres were aligned facing clockwise/counter-clockwise, you're right, it would NOT be a mag. bearing.

Here's what I THINK would happen in that scenario:
(for illustration purposes, assume the shaft is aligned vertically, and the spheres are mounted on horizontal arms, with their poles aligned with N facing clockwise)

The N poles of your spheres would be receiving mag. repulsion equally from directly above & directly below themselves.
The S poles would be receiving mag. attraction equally from directly above & below themselves.
The only physical outcome I can forsee being effected in this way is the demagnetization of whichever magnet(s) is weaker, along with partial demag. of the stronger one(s).
Also, if the spindle & arms weren't holding the spheres PERFECTLY centered between the two half-cube magnets, and/or the two half-cube magnets weren't putting off PERFECTLY identical fields, there would be a tremendous torque on the arms as the S poles of the spheres tried to align with the nearer/stronger half-cube, and the N pole of the spheres tried to align itself at the balance-point between the two half-cubes.

Like I said, this is what I THINK would happen. I don't know for sure, and I haven't done any experimentation, so don't take it as a slam, of get too upset if you disagree.

[Boston]

exactly correct on every point
except I think it will spin in the process of demagnetizing
its like suspending a pare of misalined dipoles on a pivot within a otherwise aligned field
yes you have torque between the spheres if there is so much as the slightest misalignment between the two dipoles
but
you should get spin as a result of the push pull of there fields orientation in the cube

maybe
Ill eventually build the thing and see what happens

[robherc]

my theory is that in a single field it will work but if you use a number of fields to make up the cube you end up with "bumps in the road"
I'm thinking the only way I could have made my motor spin smoothly would be to use at least one circular-polarized magnet with clockwise magnetization.
Ideally, I think it would work BEST if you used two circular-polarized magnets. The big drawback there is that you'd have to have the two magnets aligned with a VERY small gap between the magnets. I'm guessing that might have to be done in a vacuum, and with lathe-polished magnets as the requisite gap may be too small for 3 air molecules abreast! The mag interference lines from circular-polarized magnets stay VERY close to the magnet.

exactly correct on every point
except I think it will spin in the process of demagnetizing
its like suspending a pare of misaligned dipoles on a pivot within a otherwise aligned field
yes you have torque between the spheres if there is so much as the slightest misalignment between the two dipoles
but
you should get spin as a result of the push pull of there fields orientation in the cube

maybe
Ill eventually build the thing and see what happens
Good luck, & I hope you prove me wrong...I don't expect it, but surprises can be pleasant from time to time...esp. when they're useful!

[Boston]

I'm thinking the only way I could have made my motor spin smoothly would be to use at least one circular-polarized magnet with clockwise magnetization.
Ideally, I think it would work BEST if you used two circular-polarized magnets. The big drawback there is that you'd have to have the two magnets aligned with a VERY small gap between the magnets. I'm guessing that might have to be done in a vacuum, and with lathe-polished magnets as the requisite gap may be too small for 3 air molecules abreast! The mag interference lines from circular-polarized magnets stay VERY close to the magnet.

and thats exactly what is drawn in the original diagram I provided
two large apposing like poles with a slight gap between them
although not quite as small as you suggest

I suppose now that Im thinkin of that thing I could throw one together
I looked up some sources and someone makes spherical magnets
now all I need do is find some of those circular ones
get some Popsicle sticks
and some Elmers

[robherc]

lol, I heard that SOME brushless motors use circular-polarized magnets...but I know some use ring-shaped magnets that are NOT circular-polarized, so I'm not sure if it was true or not. Best way to tell would be to hold another magnet near it to see if one end attracts & the other repels: if yes, then it's NOT circular-polarized; if no, then it may be. I'll post a diagram of a circular-polarized mag. in a minute...lemme open up paintbrush now......

...and I think I've had enough experience to recommend that you at least use superglue with your popsicle sticks! :cool: lol

[robherc]

Here's the promised diagram (imagine the little black/white rectangles are the molecules making up the magnet)

[Boston]

nice !

[ancient kayaker]

If the field is entirely contained within the body of the magnet then there will be no external field, thus it will not function as a magnet. Not sure if that's what you were trying to achieve.

[Boston]

it sorta is
these things work ( maybe ) on the idea that your encasing a normal polarized object in a field that is only north
or south doesnt really mater which
kinda an artificial monopole field

[robherc]

If the field is entirely contained within the body of the magnet then there will be no external field, thus it will not function as a magnet. Not sure if that's what you were trying to achieve.

Supposedly, the field isn't entirely contained within the body of these magnets, but is kept very NEAR the body. I believe the main design issue in making motors with these magnets (check out brushless motor design...they SAY they use 'em) is that you must put the interfering field VERY close to the circ. polarized magnet...but that's not my field of expertise. All I know is that they do it, and Honda Insights/Toyota Prius' run...so it must work.

[ancient kayaker]

My understanding of brushless motor design is the field magnet has a radial field. That would require, if I understand it correctly, one pole at the center and the other on the periphery. The field has to get out to interact with rotor windings in either a motor or generator (or a sensor come to that).

[Boston]

well the reference was to an artificial monopole field

on the cube it can be easily created by taking a cube that is magnetic
cutting it in half
flipping one half over and placing two n polarized sides against one another

that creates the field that Im refering to as being monopole
its evenly distributed and only n in orientation
the armature is placed within this area
with its orientation perpendicular to the plane of the field of the cube

B

[CDK]

Boston, let me assure you that the following is not intended to insult you in any way and that no similarities between you and my neighbor are implied, but this magnetic brainchild of yours is staying alive so long that I cannot resist the temptation any longer.
Your drawing in post #46 reminds me of all the "drawings" I've seen and the stories I've heard from my neighbor in the next village. We are 2 miles apart and see each other maybe once a month, so we get along fine....
A belt driven generator / electric motor combination that needs no external power once it runs, a bulb with an unbreakable filament, a power cable without loss and a wind turbine that even generates power without wind. A very nice one was an outboard motor mounted inside a boat. The prop pushes water to the stern where it is deflected back to the bow and guided back to the prop. An ideal solution for shallow waters. Years later I saw an actual patent text for the same principle, that could also be used for trucks, trains and planes.
This guy never found the time to build prototypes for any of his inventions, but he is convinced that they will work.
He is a retired German opera singer on a liquid diet who starts the day with a bottle of beer and ends it with stronger stuff. This forum fortunately has nothing to fear from him because of the language barrier. It would not surprise me that, when confronted with this magnetic contraption, he would pull something very similar from his bookshelf.

[robherc]

AK-

I'm not sure about radial-polarity, but I just remembered a way to prove the existence of mag. fields around a circ. (clockwise, or counter-clockwise) polarity magnet....early transformers. In early transformers, donut-shaped ferrous cores were wound with differing numbers of wraps of field-inducing (power source) or field-harvesting (altered output). The fact that these worked, and would unmistakeably HAVE to create a circular-polarized mag. field, proves to me that the field-effect of a circ.-polarized magnet extends outside of the magnetic material.

That said, I'll stick with my circ-polar magnets for generating spin in a brushless motor, for now at least, or until experimentation proves me wrong. ;)

[ancient kayaker]

I have used thousands of ferrite "pot cores" in my radio and inverter power supply designs and the field is undetectable outside of the magnet; that is the reason for using them.

[CDK]

Like ancient kayaker pointed out, the field of a pot core cannot be detected: it is completely contained within the ferrite core. The same goes for ring core transformers and other wound-core designs. Only cheaply built transformers with welded together iron cores have part of their field outside. The direction and strength of the field follows the rules given by Faraday and Maxwell, no matter which core construction is used (even without one).

[mark775]

CDK, I was hoping they would drop everything and actually build it. "Hmmm, I guess we had ought to actually study magnetics, then try again. Uh, oh, there´s a lot of laws and theorems and shit here..."

[Boston]

well i am less than convinced it will work or i would likely make one
so no wories
it was just some fool thing i dreamed up years ago

got my arm in a sling so forgive my worse than typically horrible typing skills
B

I was hoping at the time to create a way to take advantage of a rare earth magnets properties in kind of passive electrical generation
and keep the thing magnetic by combining solar cells with the production technique to align the dipoles in the first place

i wanted to store the electricity in the motion of the flywheel by slowly but consistently keeping pressure on the body forcing the armature to spin faster and faster through the field

that, if it works would degrade the magnets
so i tried to dream up a way to "charge" the magnets
that's about the time I thought of using solar cells in some way


hey Jim
could a coil like whats on a old car be used to wind up the juice from a solar cell to charge a cap to then zap the magnet to help keep it "charged"

[CDK]

CDK, I was hoping they would drop everything and actually build it. "Hmmm, I guess we had ought to actually study magnetics, then try again. Uh, oh, there´s a lot of laws and theorems and shit here..."

OK, if a new crazy idea emerges I will encourage the "inventor" to actually try it.

There is a simple way to make a magnetic construction rotate or move. You must use ferrite magnets with a low Curie point. By selective heating one magnet and shielding the other, you have a simple albeit slow hot air engine that could recover energy from exhaust gases.

[mark775]

But you are talking about an active system with outside influence (made me think, how´s BMW capturing exhaust heat for added power?). I did some work with induced fields and quasi-stability in levitation (it has to be moving. Talking induced field mag-lev) on an invention of MINE and gave up until I was more prepared. I´m still not there, but have first-hand experience in being defeated by Earnshaw´s theorem and more and more appreciation of how difficult it is to go from "that should happen" to working mechanism and the doers who actually get somewhere...Also, those interested in magnetics take my word that NIB and SmCo will pinch flesh OFF and SmCo will easily shatter and threaten to blind. This stuff is not for the timid. Halbach arrays are cool and worth studying to excersize the mind and appreciate smart people, too.