It is called on the internet as Vortex Coil, but after talking to its inventors, i could not find an answer to its applications and excitation schemes. May some one please explain me how will the current flow and to for what applications i can test it ?
It's part toroid, part open loop or short solenoid, and therefore has a mixed mode magnetic field that combines both in linear superposition. There are no electrical properties that make it special. If you only want inductance with minimal external field, use a for-real toroidal winding, and if you want an axial external field, use a solenoid or simple loop. This design looks nifty but being more art than science lacks serious uses. Everything it does can be satisfied with conventional windings, separately or in combination. Here they are simply blended together. The main use for it is to make money for the supplier.
The operation of toroidal coil is when the secondary coil(conductor) placed in magnetic field B which direction is normal to the the primary current (and it forms a circular magnetic path ),due to the varying magnetic field the emf induced in the secondary coil.Toroidal coil taken place in measurements of high current ,acts as current transformer.and also this coil is used as inductor for larger inductance value because it occupies lesser space
This coil is quite easy to analyze. If you cut open the torus and straighten it out you'll have a solenoid with conductors spaced evenly around it running from one end to the other with a very slight twist, much like the served wire shield on some types of cables. This twist is too gradual to have any significant effect on inductance, and therefore it can be treated as if the conductors are straight and evenly spaced around the cylinder. First, let's assume that the conductors are in parallel. Then this approximates a straight tube for which inductance formulae are well known. If instead, the conductors are connected in series, then the inductance calculated by the straight tube formula is simply multiplied by n^2 (where n is the number of conductors) to get the actual inductance.
That is a quick analysis if the torus is cut open and straightened out, but what is the difference between the toroid form and the straight form? Not very much at all as it turns out. In comparison, with a normal toroidal coil and a normal straight solenoid, where the turns are tightly wound, the difference is that there is no end effect on the toroid, and so it will have higher inductance. The amount of this difference is the factor known as Nagaoka's coefficient which can be easily calculated. However, that would be for the case of tightly wound solenoidal coil and tightly wound torus, in which case the magnetic field is contained entirely inside the winding. In that case the end effect of the solenoid is significant compared to the toroid which leads to a noticeable difference in inductance. However, in the subject coil the current flow is mainly axial and there is really no containment of the magnetic field inside. So, the end effect would be much smaller. Hence, the toroidal case is not much different than cut open case. The net result is a big coil with little inductance, and little containment of the magnetic field. I don't see a big market for it. As Orin Laney commented, its principal value is as an art object.
I believe I saw this thing some time ago being promoted by the over-unity crowd.
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