# Asymmetrical Capacitor Thrusters: the Biefeld-Brown Effect

Back in the 1920s, a young man named Thomas Townsend Brown discovered that if he charged a capacitor with high voltage direct current, the capacitor would exhibit thrust in the direction of the + positive electrode. Off and on for the rest of his life (he died in 1985) he worked on these devices, trying to make a practical propulsion device using this principle. While in college, Brown worked with physicist Paul Biefeld, and the professor's name was added to Brown's when the phenomenon was named "the Biefeld-Brown Effect" (hereafter "B-B").

Basically, a B-B device consists of a small or sharp electrode separated by dielectric material (an insulator, in other words) from a large or blunt electrode. In this form the device is a type of capacitor. When fed high voltage (20,000 volts) DC current, the capacitor will develop thrust leading from the small/sharp electrode and away from the large/blunt electrode. Brown maintained the device thrust toward the positive + pole and away from the negative - pole, but modern experiments have shown the B-B effect works in either polarity. What is important is the electrodes must be differently sized--hence an "asymmetrical capacitor."

A lot of people maintain the B-B effect is electrogravitic; that is, the electrical current acting on the capacitor somehow counters, or interferes with normal gravity. I do not believe this. The effect is clearly the result of excess ions being thrown off the small/sharp electrode, flowing toward the oppositely charged large/blunt electrode. In normal air, the ions pick and charge air ions, adding to the cascade and increasing the thrust. In a vacuum, or under insulating oil, asymmetrical capacitors can still exhibit thrust, though it is usually much weaker. This is because only the ions coming off the forward electrode are present without charged air ions to help push.

This Instructable will describe how to build twin rotary thrusters as a demonstration of the Biefeld-Brown effect. If you prefer to believe this is a form of anti-gravity, you are welcome to do so. My purpose is show you how to build the device, not debate Brown's electrogravitic theories.

New video as of 8/3/2012, showing new type rotors powered by relatively low voltage from a microwave oven transformer:

New video of the thrusters with a different power supply:

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sitearm3 years ago
@Mr.Apol; The video was good to watch; I am curious why you turned lights off for part of it (I was looking for green glows or something). The instructions were even better, especially learning what can be done with old CRT's. My favorite line from your Instructable was, "May have weird side effects around your house." Nothling like playing around with 20,000-30,000 volts at home :)

Cheers! :)
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Mr. Apol (author)  sitearm3 years ago
I turned the lights out to see any corona, etc. from the thrusters. In fact there is quiet but noticeable discharge between the electrodes. Since sparking is bad for thrust, I'd like to eliminate it, but I haven't found away to do so entirely, yet.

Paul
Mr. Apol (author)  Mr. Apol5 months ago

Sparking can be eliminated by using resistors (rated for high voltage).

3 years ago
@Mr. A; Oh! And I forgot, there is a wonderful SciFi story from years ago where the government showed a scientist an alien antigravity machine and, after that, he struggled to finally make one, which was 1,000 times bigger and heavier. After he showed them that it worked, they admitted to him that they had faked the evidence. Because he (by fiat) believed that it could be done, he came up with a working prototype. Ah, the SciFi of a few decades ago...

Cheers! :)
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3 years ago
@Mr. Apol; Hi! OK I will look again to see the discharge. However, as you wrote, discharge between the electrode does create .. interesting effects.

*now is thinking of Bride of Frankenstein but that's for another post*

Cheers! :)
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leviterande1 year ago
I know that ionization is 99% of all asym. caps results. However I am 99% sure that true real strong propulsive force is made with all asym caps. how is everything going now?
Mr. Apol (author)  leviterande1 year ago
I have made a few modest experiments trying to isolate the force that propels the ACTs. I've found nothing at work but ionized air. There have been a number of serious experiments done by NASA, the Army, etc., but no true "electrogravitic" force has been found.

PBT
1 year ago
Germans began work on a magnetic propulsion unit long ago but the guy who was in charge of the program never finished the prototype before the end of the war last i saw his family keeps it in their house now it looks almost done but you can tell some parts from it are missing i wouldn't be surprised if it worked though since it was captured germans that got the US space program going after their scientist where captured and forced to work for us in a base not far from 51 if i'm correct i forget the exact name of the base anyway you should be able to find some info and maybe the video on it from the history channel somewhere on you tube
1 year ago
there are so many stories about such propulsions coming from Germany before and during the war. I believe most of them are true.. but which one are you referring to?
bart4163 years ago
This sounds a lot like what we call electric/ion wind. You can also get the same effect with those tin foil gliders you sometimes see at physics demonstrations actually. In general you get a lot of funny effects when strong charge gradients are at play. You can do some pretty neat things with these sort of setups. Like blowing out candles. But it's generally nothing more of a curiosity as the power supplies are fairly heavy compared to the generated thrust at the moment. Additionally these do not work in a vacuum as they ionize the air and accelerate it towards the other electrode. You could probably get a higher thrust out of this by making some holes in the front actually, or leaving some space around it. That'd also partially solve the sparking problem most likely as there would be a constant airflow instead of a volume of air where the charge constantly builds to the point where a discharge is possible.
Mr. Apol (author)  bart4163 years ago
There is some evidence thrusters work in vacuum, otherwise NASA would not have been interested in them. They apparently don't work as well as they do in air, since they lack the cascading effect caused by air ions joining the flow.

PBT
3 years ago
Contrary to popular belief NASA also puts quite some research efforts into conventional propulsion inside the atmosphere. And there is no cascading effect, there is simply the effect of ionizing a gas. Put one of these under a bell jar with no other metal parts in the neighbourhood with whatever system you wish to use to measure force. You'll find nothing. These things work by ionising a gas and accelerating it. If there is no gas in the immediate area and it still works that means you are either ionising your electrodes (very bad as they won't last long in that situation) or you're working with an electron beam but that's impossible or extremely unlikely for reasons I won't even get into explaining. If you don't believe me you might want to read up a bit more on how electrohydrodynamic thrusters actually work.
Mr. Apol (author)  bart4163 years ago
The French apparently had some success with thrust in a vacuum, but ultimately their tests came to nothing:

http://projetmontgolfier.info/INTRODUCTION.html

I believe the Bahnson series of experiments also claimed some thrust in a vacuum, but I'd have to check.

Certainly under the right conditions (not in this device!) ionising the electrodes could occur. Isn't this the basic principle of the ion enginem a substance like caesium as the ion fuel?

I use the term cascade in its ordinary meaning, "a connected series, as of amplifiers for an increase in output." I suppose a better term might be an avalanche, wherein a small disturbance grows larger by taking new portions with it. The language is merely meant to be descriptive, not definitive.

Don't get me wrong. This effect is caused by ions. As I said, I don't believe in anti-gravity.

PBT
3 years ago
Actually, this is why it's so important that no metal objects are in the neighbourhood. We tried it as well, and the force in the area pretty much ended up being the magnetism. It's also important you have a hard vacuum. A cheap vacuum pump won't do. Even with a bit of air it'll still cause some force.
Mr. Apol (author)  bart4163 years ago

PBT
3 years ago
We = our class (if you can call it that)... We've done a lot of things as students. Many of those should never be spoken about. Often it went way out of control.
Mr. Apol (author)  bart4162 years ago
You might find this interesting: asymmetrical capacitors sealed in resin still turning under power:

PBT
tzq33tdq2 years ago
are there kits??? and would it work if it had a higher voltage???
THIS IS EXTREMLY EPIC!!!
Mr. Apol (author)  tzq33tdq2 years ago
No kits, sorry. That's what the Instructable is for. :-)

Higher voltages give greater thrust. Tests have been made with B-B devices up to 300,000 volts and more.

PBT
T0C2 years ago
This is seriously awesome.
But can I use a 555 driven Flyback to drive it? it can put out well over/under 20kV and it's rectified.

(Also about the CRT, when you take out the suction cup touch it to ground also take a ground wire and touch the hole where the suction cup was, just to be safe. Some monitors have up to 75kV inside and that probably will kill you. )
Mr. Apol (author)  T0C2 years ago
A flyback would certainly work. The output is rectified (that's the power source in a CRT).

CRTs need to be handled carefully, that's for sure.

Paul
2 years ago
Well then I guess I'll get started now.

Hehe learned that the hard way years ago...

Really cool instructable btw!!
They could use this for space ships. Use the pulse effect to slowly gain speed. Using nuclear reactors for the energy source. Would these be for effecient than Proton shooting method?, and possibly more effective while keeping a stable system?
Venus Flytrap3 years ago
How about using magnets to produce a very low resistance bearing ?
Mr. Apol (author)  Venus Flytrap3 years ago
Magnets would work to make a 'floating' bearing, but you need a rotating connection point too--a commutator--which magnets would prevent. Current has to flow through the spindle to the thrusters. But maybe you could incorporate the two ideas, magnets and commutators?

Give it a try!

PBT
3 years ago
I'm thinking... what if you put an inductive coil on each side of the magnetic bearing, and put a rectifier into the circuit on the spinning part? That way you can get your magnetic bearings, and not contact at all for the contacts. I mean, it wouldn't be winning any prizes for efficiency, but it might work out really cool anyway. Maybe that's what a commutator is, I'm not familiar with those. It also occurs to me that the magnetic field of the inductors might mess with your bearings.
Mr. Apol (author)  SpudGunTechie3 years ago
Interesting . . . don't know if it would work, but I like the idea. (A commutator is simply an electrical connection that moves, usually some sort of rotary brush, etc. You find them in motors, generators, etc.)

PBT
Thomas Meek3 years ago
Is the Biefeld-Brown Effect the same principle that makes the "electric Whirlie" go?
Mr. Apol (author)  Thomas Meek3 years ago
Basically, yes. The ACT is more powerful because it uses both poles (having a trailing, oppositely charged electrode accelerates the ions) while a simple ion whirligig does not.

PBT
Dream Dragon3 years ago
I am really fascinated by this, I've seen the "Ion Lifter" experiments and wondered if they were a similar principle. Well done for posting this fascinating demonstration.
just mike3 years ago
I think it would go faster if you used Red Bull cans instead of Pepsi. :)
blackcorvo3 years ago
Wait... a ceirtain scientist named Brown created an incredible kind of capacitor, and died in 1985.

WE'RE IN THE WRONG TIMELINE, MARTY!
ocaptain3 years ago
Is this the supposed propulsion system for the Star Wars TIE Fighter, where TIE stands for "Twin Ion Engine"?

Match this engine up with this baby:

http://technabob.com/blog/2010/08/14/life-sized-tie-interceptor-star-wars/

and we can start our galactic empire!
ProCactus3 years ago
Hello,
Wow, ill have to look into this, Bizzare

And maybe next time you can narrate the video.
I had to stop watching, Like watching grass grow.
slilleker3 years ago
very interesting! I ponder if this is somehow relates in theory to Tesla's Flying machine - which never came to fruition, people have done experiments using weights and stuff but i think its meant to use magnets rotating within a chamber which is charged so there is a constant thrust.
Ortzinator3 years ago
Thrusters to maximum!