Capacitive Power Coupler & Capacitive Machine

[markdansie]

This could be a real paradigm shift in electric motor and generator technology.


http://revolution-green.com/capacitive-power-coupler-capacitive-machine/


Kind Regards
Mark

[TinselKoala]

Yes, indeed interesting.

C-Machine™ Capacitive Machine The second machine is an electrostatic motor. Although not as advanced in its development C-Captive are claiming the following:

   
• Electrostatic motor designed as a full replacement for existing motors and generators
• Produces high-torque at low-speed
• All-aluminum and recyclable
• Lightweight
• Does not require a gearbox
• Achieves smooth rotation and minimal noise
• Designed to operate at 95 percent efficiency, cutting energy loss by a factor of 3 over conventional motors

Status: Prototype nearing completion and will begin Beta Testing in 2014.

Is it 2014 yet? I really want to see this particular prototype in operation.  My own experience with electrostatic motors makes me tend to doubt that they can achieve some of these design goals. However I am happy to be proven wrong, with evidence. I can certainly believe that they are not as advanced in development with this project.

[TinselKoala]

Argh. Now that I have watched the demonstration video I am really depressed. I used essentially the same system, except with concentric, airgapped cylinders instead of facing plates, for capacitive power transfer to rotating equipment back in 2000 and 2001. But nobody thought it was significant or important back then, it was just a useful lab kludge to get power where it was needed.

In my opinion, now, having experience with both capacitive power transfer and EM transfer, there are very few situations where the capacitive solution would be the better choice.


ETA: the more I read the more depressed I get. What, exactly, is really new in this company's demonstrations? They appear to have patented common items of electrical art that have been known for over a hundred years, some of them, just arranged slightly differently. Benjamin Franklin would be more interested in the HV power supply and diodes. The actual "capacitive coupling" and motoring part would be completely familiar to him. He might marvel at the transparent plastic but the operating principle was first used by him, after all.

http://www.youtube.com/watch?v=ir9RIsXzmzY   (2008)

http://www.youtube.com/watch?v=vqf3bUL4YqE   (2009)

[conradelektro]

@TinselKoala:

The new thing are the "flexible plates" which allow for a very small air gap between the rotor and stator plates.

In the video on this page http://www.c-motive.com/our-technology-products/ see from minute 3:20 onwards.

The very small gap between the plates is held by air flow and the flexibility of the plates corrects the distance (slight wobble).

The invention is the design of the flexible plates (which makes a very small gap between rotor and stator plates possible) and not the motor principle (which is known since the 19th century).

But I do not know whether the very small gap really makes a great difference. It could well be. In an electrostatic machine mechanical precision is the main hurdle for creating a very small air gap. May be the flexible plates are a good way to create a very small air gap with manageable precision.

Modern electronics also makes high Voltage (e.g. 20.000 Volt) more manageable. May be the time for the electrostatic motor has finally come.

Greetings, Conrad

P.S.: http://www.designworldonline.com/noncontacting-slip-rings-capable-kw-level-power/

One of the first prototypes used rigid plates, but the design team could not position them close enough because of mechanical tolerances. "There is always a little wobble and misalignment. Our inventing devised a way to achieve levels of capacitance no one has done before," he says.

The plates, now flexible, sport an aerodynamic fluid bearing between them. "Because they flex, they float on a cushion of air making them quite durable. You can shake the assembly while running and the plates do not touch," adds Reed.

[TinselKoala]

Yes, I see that, thanks. They say that they are able to achieve separations closer than 0.004 inch with their flexible plates. That is closer than my concentric cylinder system but not by very much. And for any capacitor to hold off voltage it has to have a pretty good dielectric in between the charge-carrying plates. It doesn't take much voltage to jump a 0.004 inch air gap. So I can believe that they have large capacitances, maybe... but not at high voltages without something other than air in between rotor and stator plates. Capacitor plates also experience an attractive force from the opposite charge concentrations. I am having a lot of trouble understanding how an air cushion can keep two oppositely charged, flexible plates from making contact, at any point, when their nominal separation is that small to begin with. But certainly my system didn't use any deliberate air cushion. So OK, good on them for that improvement in the art.

Does the air cushion come from the spinning itself, or is it supplied by an external source of compressed air? If the first, then what happens when the thing isn't spinning but power still needs to be transferred? If it is externally supplied, what happens if that supply is interrupted for some reason while the system is operating at kiloWatt power transfer levels?

I once built a large Bonetti machine using thin polycarbonate discs. This plastic is a lot more flexible than acrylic. The electrostatic forces on these rotating discs would pull and push at different places around the discs and set up a travelling warp that was frightening to behold. Yes, the discs crashed together in places in spite of the "air cushion" between them (about 30 times larger than their gap!) But the voltages in that machine were over 200 kV so the forces were correspondingly large.

All of that still doesn't apply to their ES motor though, just the capacitive power transfer system.