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DekuTree64

Wed Mar 25 2015, 09:06PM

Registered Member #54596 Joined: Fri Mar 06 2015, 11:31AM
Location:
Posts: 19

Anybody working on this these days? That is, developing new methods and analysis beyond simply replicating the triangular lifter with TV/monitor flyback-based power supply. Seems like nobody's really done much in the past 10 years or so... Blaze Labs still appears to be the state of the art, as far as I've found. Also after reading through all the past lifter threads on this forum, Tesladownunder's page here http://tesladownunder.com/Lifters.htm is good, especially confirming that thrust continues to increase with voltage at 80kV.

The theory of operation that I'm going on is that you expend one unit charge at the emitter to ionize one air molecule, after which it "falls" into the collector's electric field, bumping into neutral air molecules on the way, and then expends one unit charge from the collector to de-ionize.

The higher the collector voltage, the farther you can pull an ion from. Energy is only expended in the creation and neutralization of the ion, so the longer distance you can pull it through, the more neutral air molecules you can bump with it for the same emitter/collector current, thus increasing the thrust. Energy usage does increase as well, because it takes more power to maintain the collector at a higher voltage, but according to Blaze Labs, the increase in thrust far outweighs this, with thrust per watt increasing by voltage to the 1.9 power http://www.blazelabs.com/l-perf.asp. Not sure how well verified that is at higher voltages (like hundreds of kV), but hopefully it holds.

I've been investigating the possibility of using electrostatic machines as the power source, because of their natural tendency toward extremely high voltages, especially as you scale them up. Also, a disc-based generator naturally fits inside a flying saucer type craft, which is the form I would most like to make work. Plus it gyroscopically stabilizes the craft, so you can fly fast sideways without "snagging" on the air and flipping up.

Thus far, my experiments with electrostatic machines haven't been particularly successful. I built an 8" Wimshurst, and 16" Bonetti (sectorless Wimshurst) machine. Both can produce a gentle breeze and lovely glowing purple curtain from emitter to collector on a standard triangular lifter, but not enough current to fly anything. And the Bonetti requires a spark gap between the positive terminal and the corona wire on the lifter, or else it drains all the charge off the discs within a couple revolutions. But the spark gap seems like a big waste of energy, so I'm not surprised it won't fly. My machine is pretty "leaky" overall as well. And the standard Wimshurst is of course a terrible design of machine for anything that needs significant current like this (I really only built it for practice). I suspect a Pidgeon or Wommelsdorf would be the best of the classic machines for it.

One interesting thing that occurred to me is that because it doesn't take that much voltage to ionize air from a thin wire, the emitter doesn't actually need a big generator to power it. A small, high speed, multi-disc machine should work for that. And give it foil sectors to eliminate the spark gap problem of sectorless machines. Then use a large sectorless machine for the collector. And since each machine outputs positive and negative, do a two stage thruster to utilize both outputs of both machines.

Here's my current idea for a flying saucer:

My theory is that with a saucer, you just need to create a small difference in air pressure between the upper and lower surfaces, and then the large surface area will allow that to support a lot of weight. The conical top surface should "throw" air away to create a vacuum, and the convex lower surface should cause the ions moving from the outside in to "squeeze" the craft upward. Though it may be that this direct squeezing force is too small to do anything, and since the ions are moving in a thin sheet right at the surface, they're not running into that many neutral air particles either. So it may be better to have a concave bottom and just pull as much air under there as possible.

So, next time I'm in the mood to work on this, I'm going to try building two motorized electrostatic machines to power it. One large sectorless, using the "triplex" system to get more charge density on each disc, and one small sectored machine with lots of discs. Although it may be an even better idea to forgo disc-based generators entirely for the emitter, since the scalability of voltage for the collector is what I really want from them.

Antonio

Thu Mar 26 2015, 12:04AM

Registered Member #834 Joined: Tue Jun 12 2007, 10:57PM
Location: Brazil
Posts: 644

Even a small "lifter" needs a good fraction of a mA to lift, at about 20 kV. An electrostatic machine of usual design has no problem in reaching enough voltage, but would have to be quite big and heavy for this current.

DekuTree64

Thu Mar 26 2015, 01:13AM

Registered Member #54596 Joined: Fri Mar 06 2015, 11:31AM
Location:
Posts: 19

Hey there, Antonio! Many thanks for your web site. That, along with the old book "Modern High-Speed Influence Machines", is where I learned the ways of electrostatics.

I do agree with you on the current. And I also doubt my electrostatic machine inside a flying saucer concept will ever be able to lift itself... but I do think it's worth exploring the direction of higher and higher voltages.

And it seems to me that what is needed for smaller experiments is not a bigger machine, but higher speed. Something like 30cm discs spinning at 5000 RPM.

What I was thinking for a machine is to take just the center two discs of one like your triplex Wimshurst, and replace the outer two discs with two pairs of stationary inductors (similar to the Holtz machine). Hopefully charging the inductors from the front sides of the discs would avoid the polarity reversal that the Holtz is prone to.

So, you have two discs, spinning the same direction, with neutralizers and charge collectors between them, and stationary inductors outside. Now add another pair of discs, spinning the other direction, with another set of neutralizers and charge collectors between them. Theoretically you could just keep on adding disc pairs, but I'd rather stop at two, because then you can mount them directly on the shafts of two motors. Four discs, all with the boosted surface charge density of the triplex system, and no belts needed to drive it. And since nothing actually needs to contact the disc surfaces for electrostatic machines to run once they're started, the speed is really only limited by the quality of construction and materials used. Should work with or without sectors, but I'll be doing sectorless.

Another thing I've been investigating is lighter weight disc materials, which should also help with the high speed. Corrugated polypropylene works, though not as well as solid acrylic. But it's 1/3 the weight, so that's good. I also tried foam core poster board, but it didn't work... I think it may have had some anti-static treatment. I'd really like to try styrofoam, with thin plastic glued to the surface for strength and stiffness, but haven't been able to find a source for thin, flat styrofoam sheets.

Patrick

Thu Mar 26 2015, 07:42PM

Registered Member #2431 Joined: Tue Oct 13 2009, 09:47PM
Location: Chico, CA. USA
Posts: 5639

Ive been working on them since 1995, I was a young scamp. My high voltage probes were all meant for this purpose, though I always kept my lifter research secret. Alexander P. DeSeversky was a mad man, like us all here on the forum...

Ill be loosening my paranoia/secrecy and opening up to others shortly. Particularly here on the forum. (hence the multirotor tangents recently) My research tends to head towards the wave drive idea to reduce energy loss, Evgenij Barsoukov explains this well, and he's not a pseudo-nut-case.

As, said, mass/power/thrust ratios are all the killers, as with any flying contraption. Now with a arsenal of HV resistors I should be good to go forward soon.

As Im paranoid, and secretive, I just hope others cite Evgenij Barsoukov and myself, and don't steal our work.

HV Control Electronics:

High voltage flyback in oil. And my high-bandwidth oscilloscope.

HEI coil, and push-pull ignition coils from a "waste one spark" car engine.

Common NST.

Close up.

micro-controller / laptop logic box, which commands the power box.

Im also following the work of JP Aerospace in Sacramento, CA. Just wish they'd return my emails. they send ballons to 100,000 feet.
Above all else - - avoid the pseudoscience garbage that so often accompanies this phenomenon.

DekuTree64

Thu Mar 26 2015, 10:43PM

Registered Member #54596 Joined: Fri Mar 06 2015, 11:31AM
Location:
Posts: 19

Hi Patrick! Glad to hear you're still working on this. I saw your name a few times when reading through the archives, but thought your recent multirotor work may have meant you'd given up on it. Then again, I've been thinking about building a quadcopter for learning experience. Computer controlled balancing would probably be good for ionocraft as well.

The wave drive idea is where you use alternating currents to "surf" ions without ever neutralizing them, right? Seems like a great way to go. Just very tricky. Pretty much like a particle accelerator, really... which is what ion propulsion is, anyway, regardless of how you do the accelerating. And it eliminates the difficulty of containing extreme voltages, which I'll be dealing with.

Don't loosen up your paranoia too much :) I would love to hear all about your and Evgenij's work, but don't want to see you get screwed either. Nothing worse than working on something for a long time, only to have someone else patent it and prevent you from doing any more. I just with there was a way to anti-patent ideas... anything I come up with, I'd rather not prevent anyone else from working with it, but I don't want to be blocked myself either.

And yeah, all the pseudoscience stuff is why I wanted to post on this particular forum. I'm usually not so averse to fringe science, but in this case I'm really only interested in solving the engineering problems of an effect that's explained perfectly well by conventional theory.

Patrick

Thu Mar 26 2015, 11:04PM

Registered Member #2431 Joined: Tue Oct 13 2009, 09:47PM
Location: Chico, CA. USA
Posts: 5639

Well there is a charge recovery wire. So youd have ground/corona wire close torgether, then alternating rods for distance then the ground wire.

The ions are generated then alternate, then are removed. leaving the entrained air with momentum but no charge.

Sulaiman

Fri Mar 27 2015, 12:36AM

Registered Member #162 Joined: Mon Feb 13 2006, 10:25AM
Location: United Kingdom
Posts: 3141

I thought that once a patentable idea is published (e.g. on 4HV) that it is no longer patentable.

Ash Small

Fri Mar 27 2015, 02:54AM

Registered Member #3414 Joined: Sun Nov 14 2010, 05:05PM
Location: UK
Posts: 4245

Sulaiman wrote ...

I thought that once a patentable idea is published (e.g. on 4HV) that it is no longer patentable.

+1

EDIT: I think it means no-one else can claim a patent if you have already published here, or elsewhere on the internet, or anywhere else.

BigBad

Fri Mar 27 2015, 03:23AM

Registered Member #2529 Joined: Thu Dec 10 2009, 02:43AM
Location:
Posts: 600

No, patents are issued to encourage people to publish when they otherwise wouldn't.

If you've already published to the general public, then you cannot get a patent- at least in the UK.

In America, there was a thing where you could publish, and up to a year later claim a patent on it. I'm not sure whether that's still valid or not, the American system has been bought more into line with the rest of the world; they're now on a first to publish scheme, rather than first to invent because it's easier to administer and many things have changed.

However, if you have a patent in the UK, I don't think that prohibits you taking out a patent on the same thing in America.

Patrick

Fri Mar 27 2015, 06:00AM

Registered Member #2431 Joined: Tue Oct 13 2009, 09:47PM
Location: Chico, CA. USA
Posts: 5639

Once in the "public square" .... you cant patent.

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