Just for FUN: 50kV High Speed Electrostatic Corona Motor
Beau Schwabe
Posts: 6,566
Video:
https://www.youtube.com/watch?v=lqaV7iEl3rM
Talk about fundamentals (in reference to another thread)
It's really interesting what you can do with a plastic popcorn container, some aluminum foil, a couple of screws, a few pieces of wood, and a 50 thousand volt power supply! :-)
Since this motor does not use a magnetic field, it is very light weight, making it a likely candidate to be used in space where the weight of the payload makes all the difference.
Also, the input power to the 50kV generator is a good fit for solar applications. For this particular model, the voltage supply was only 12V at about 9 Amps ... A 100Watt panel would work just fine with similar results you see in the video.
This is a high speed Electrostatic Corona motor. This motor was made from a plastic popcorn container, where aluminum adhesive tape was placed on the the inside walls. The "ribs" alternate in polarity with a voltage of about 50kV. The theory of operation creates a standing electrostatic field alternating polarity between each rib, thus the number of ribs needs to be an even number. Assuming we start with a negative rib, electrons are deposited on the plastic surface of the container and repel the negative rib. At the same time they are repelling the negative rib they are attracted to the next adjacent positive rib where they are removed from the plastic surface. This leaves the plastic surface under the positive rib with a positive charge, likewise repelling the positive rib and being attracted to the next adjacent negative rib where the process starts all over again. The metal foil inside the tube takes on a charge equal to half of the voltage supply and can be modeled as two capacitors in series with regard to the HV supply terminals. The "center" terminal of the two series capacitors IS the metal foil on the inside of the container.
A slight angle on the rib blade (just a thin edge of the aluminum foil) ensures that the motor will spin in a particular direction on start-up.
The severe arching is because we made some improvements to the Fly-back driver. The supply power to the Fly-back circuit is 12V at about 9 Amps. Under normal circumstances the motor does not arc, except for start-up. See my other video with the same motor being powered with about 30kV. The supply power to that video is 22.2V at about 5 Amps. Improvements were made for this video warranting a new Corona motor design in the near future. :-)
Other video using a 30kV power supply and a less efficient power transfer to the Fly-back transformer:
https://www.youtube.com/watch?v=LV1hH56cdcM
https://www.youtube.com/watch?v=lqaV7iEl3rM
Talk about fundamentals (in reference to another thread)
It's really interesting what you can do with a plastic popcorn container, some aluminum foil, a couple of screws, a few pieces of wood, and a 50 thousand volt power supply! :-)
Since this motor does not use a magnetic field, it is very light weight, making it a likely candidate to be used in space where the weight of the payload makes all the difference.
Also, the input power to the 50kV generator is a good fit for solar applications. For this particular model, the voltage supply was only 12V at about 9 Amps ... A 100Watt panel would work just fine with similar results you see in the video.
This is a high speed Electrostatic Corona motor. This motor was made from a plastic popcorn container, where aluminum adhesive tape was placed on the the inside walls. The "ribs" alternate in polarity with a voltage of about 50kV. The theory of operation creates a standing electrostatic field alternating polarity between each rib, thus the number of ribs needs to be an even number. Assuming we start with a negative rib, electrons are deposited on the plastic surface of the container and repel the negative rib. At the same time they are repelling the negative rib they are attracted to the next adjacent positive rib where they are removed from the plastic surface. This leaves the plastic surface under the positive rib with a positive charge, likewise repelling the positive rib and being attracted to the next adjacent negative rib where the process starts all over again. The metal foil inside the tube takes on a charge equal to half of the voltage supply and can be modeled as two capacitors in series with regard to the HV supply terminals. The "center" terminal of the two series capacitors IS the metal foil on the inside of the container.
A slight angle on the rib blade (just a thin edge of the aluminum foil) ensures that the motor will spin in a particular direction on start-up.
The severe arching is because we made some improvements to the Fly-back driver. The supply power to the Fly-back circuit is 12V at about 9 Amps. Under normal circumstances the motor does not arc, except for start-up. See my other video with the same motor being powered with about 30kV. The supply power to that video is 22.2V at about 5 Amps. Improvements were made for this video warranting a new Corona motor design in the near future. :-)
Other video using a 30kV power supply and a less efficient power transfer to the Fly-back transformer:
https://www.youtube.com/watch?v=LV1hH56cdcM
Comments
Said the safety-minded guy who builds flamethrowers into everything.
Now you have me wondering how to make a "Corona" motor out of a glass beer bottle. Lime-powered, natch.
A little bit of 3-D printing to hold the bottle centered and you should be good to go. Minus the "ship in a bottle" scenario on how your going to get the inside lined with aluminum foil. As far as lime powered.... ehhh... that would be a lot of limes! :-)
What's crazy scary is that the primary of the FBT only has 6-turns of wire center tapped, and the MOSFETS run cool without a heat sink even after extended periods of operation. Also, that amount of power being unleashed is about half of what powers a typical laptop computer.
Thanks for sharing it with us.
X-rays from a flyback transformer? Never heard of such a thing. X-rays from a high voltage rectifier tube...sure. Even from a CRT. But not the transformer.
Under normal circumstances this motor is only supposed to arc like that upon initial start up.
It was severely being over-driven due to the increase efficiency redesign of the power supply.
...However given my latest job predicament, a little radiation might do me some good.
As with any vacuum tube, there is a cathode, which emits electrons into the vacuum and an anode to collect the electrons, thus establishing a flow of electrical current, known as the beam, through the tube. A high voltage power source, for example 30 to 150 kilovolts (kV), is connected across cathode and anode to accelerate the electrons. The X-ray spectrum depends on the anode material and the accelerating voltage.[4]
Are the x rays from this corona motor enough to worry about, I doubt it.
Wonder how much BED he's receiving? ;-)
Amanda
Electrostatic motors are already hypotesized for use in space without all that lossy discharge they can even be efficient. http://revolution-green.com/high-power-electrostatic-motor-95-efficency/
Probably not much, but there is enough UV to be a concern, which is why Beau recommended not looking at the spark. There's a reason arc welders wear long sleeve shirts (sunburn), face mask, and goggles.
I thought you were being overly cautious when you warned me about looking at the spark back when I played with a spark gap ignitor.
You were very correct about the possible harm from the UV light. My eyes hurt like the dickens for most of the night.
I don't think my skin burned (and my skin starts to burn immediately in the sun).
Still, better to be cautious, UV scorched eyes is like having ground glass poured onto you eyeballs and can go on for days. Don't ask how I know, it was too stupid.
My point is that corona discharge, the means charge is transferred on and off insulators in air, doesn't
work in a hard vacuum because its the breakdown of air into ions that carries the charge. Anyway you don't
want discharge at all in an efficient electrostatic motor, just charge moving around the surface of conductors.