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:

Another video showing the ACTs powered by a handcranked Wimshurst machine:

Step 1: Parts you will need

Here is a list of the materials you will need to build the thrusters:

1 polyethylene cutting board, 14 x 17 inches by 3/8ths inch thick
      other sizes and materials will work; wood will do if you coat it with insulating varnish

5 feet of 1/2 inch PVC tubing
      ordinary hardware store plumbing pipe, white

2 1/2 inch PVC "T" joints

1 1/2 inch PVC 90 degree elbow

5 1/2 inch PVC end caps with flat ends
     A lot of pipe caps come with rounded ends. Try to find squared-off, flat caps.
     See http://www.creativeshelters.com/fittings/Display-All-PVCFittings.aspx for example

1 1/2 inch PVC plug

10 inches of 1.25 inch (about 40 mm) cardboard tubing
     I got this from a roll of holiday wrapping paper. It should be as light -weight as possible without
     compromising strength

2 12 oz. aluminum soft drink cans, any brand

2 aluminum discs, 40 mm diameter
     Again, these should be as thin as possible to save weight, but be rigid too.

a few square inches of rubber sheet about the thickness of a coin
      Foam rubber will do if it's dense

4 rubber appliance "feet" with 1 screw each
      
about 14 inches of 1/4 inch hardwood dowel
      Poplar, basswood, etc.

6 feet of 22 gauge bell wire

6 8/32 brass bolts, each about 1 inch long

1 8/32 brass bolt, about 1.5 inches long

2 aluminum 8/32 threaded spacers, about 1 inch long

1 8/32 washer (brass, aluminum, or steel is OK)

3 knurled brass 8/32 nuts

3 8/32 brass hex nuts

1 resistor, about 4 megaohms

shellac or polyurethane varnish

Super glue

aluminum HVAC tape

tube cutter, scissors, sharp knife, paper hole punch,  a drill with 1/4, 1/16" and 8/32 bits

power supply--see separate page for info

Comments

[bart416]

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]

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

[bart416]

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]

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

[bart416]

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]

OK, I have to ask: who's "we?" I'd like to hear about your experiments.

PBT

[bart416]

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]

You might find this interesting: asymmetrical capacitors sealed in resin still turning under power:

http://www.youtube.com/watch?v=-eqU1bDFtgI&feature=mfu_in_order&list=UL

PBT

[tzq33tdq]

are there kits??? and would it work if it had a higher voltage???
THIS IS EXTREMLY EPIC!!!

[Mr. Apol]

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

[T0C]

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]

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

[T0C]

Well then I guess I'll get started now.


Hehe learned that the hard way years ago...

Really cool instructable btw!!

[Flying_MashedPotatoes]

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 Flytrap]

How about using magnets to produce a very low resistance bearing ?

[Mr. Apol]

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

[SpudGunTechie]

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]

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 Meek]

Is the Biefeld-Brown Effect the same principle that makes the "electric Whirlie" go?

[Mr. Apol]

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 Dragon]

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 mike]

I think it would go faster if you used Red Bull cans instead of Pepsi. :)

[blackcorvo]

Wait... a ceirtain scientist named Brown created an incredible kind of capacitor, and died in 1985.

WE'RE IN THE WRONG TIMELINE, MARTY!

[ocaptain]

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!

[ProCactus]

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.

[slilleker]

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.

[Ortzinator]

Thrusters to maximum!

[grenadier]

The reason it works is because round electrodes don't emit corona easily, while pointy ones spew it out like mad. So if only one side is spewing electrons, there is bound to be some sort of thrust!

[slack-man]

This was a cool build. I've had an interest in the B-B effect for quite some time. Jean-Louis Naudin has done a lot of research with various "ionic" thrusters, including the NASA "Orbital Maneuvering Propellantless Thruster", based on US patent 6411493.

"Lifters" are a interesting related device that is easy to duplicate. A quick google search will bring up JNL Labs and other sites.

[arthujt]

summit racing has a 30 dollar 60kv ignition coil that might give a little more boost for your project! www.summitracing.com
I have used some in my HHO projects that work just fine!

[Mr. Apol]

Ignition coil output is AC and won't work on thrusters unless rectified to DC--but it's a good idea.

PBT

[jesteract]

The video shows the High Voltage DC supply being generated off a PC monitor's EHT and the monitor's power is fed through a Variable Mains transformer... Hmm Don't think there's enough control through the variable transformer, as PC monitors firstly nowadays come as universal 100-264VAC 50/60 Hz mains and secondly if the mains input AC supply is lowered the EHT circuit will simply stop functioning if the input supply's below the lowest threshold, mainly due to the fact that the Switched Mode power supply circuitry on the monitor's board would shut down, thus not providing the required control voltage for the line driver circuitry.

A simpler EHT supply could be designed using an EHT transformer with a wire looped twice around the ferrite and the ends of this wire connected to an electronic halogen transformer and a halogen bulb as a dummy load. The electronic halogen transformer could then be connected to a conventional mains dimmer. up to 65KV can be generated off a surplus EHT coil in this manner.

[Mr. Apol]

Actually the variac powers the CRT monitor at AC voltages as low as 70, but the monitor does shut down below that. The main function of the variac is to provide a safe on-off switch.

All sorts of DC power supplies are possible. I chose the CRT as being the easiest to set up.

PBT

[menahunie]

As you mentioned it is the Ions that is causing the thrust.
A very very low powered Ion "engine".
I did a similar project in school and made little rockets on a pendulum causing them the swing.

[sitearm]

@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! :)
Site

[Mr. Apol]

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

[sitearm]

@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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[sitearm]

@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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[Electorials]

wtf!
I didn't know this was possible!
Nice creation ;)

[gorth]

This is a simple ion engine. I built one of these in the 70's from a plan in a 1969 encyclopedia. Very cool !!!