The present invention relates to a transformer for producing high electrical currents.
With a transformer known from DE 44 23 992 C2 for production of high electrical impulse currents, which is part of an electromagnetic generator for quick current and magnetic field impulse for production of magnetic fields in conversion technology of electrically conductive materials by means of a magnetic field, the primary coil is coiled as an elongated coil in a spiral on a longitudinally slotted supported tube made from copper or another electrically conductive material, which forms the secondary coil with an iron core and are welded or screwed onto the contact block for the current output to a high current loop on the secondary side of the transformer on both sides of the longitudinal slit. The contact blocks are disposed in the center of the support tube, which is provided on each side of the two contact blocks with this type of primary coil.
With a different type of impulse-transformer with one or more primary coils arranged on a tube-shaped, longitudinally slotted high current conductor (DE 198 47 981 A1), the high current conductor comprises a flange fixedly connected with the conductor, which, like the high current conductor, is made from a massive electrically-good conductive material and projects out over the diameter of the primary coils.
With a further known, multi-winding coil for producing intense magnetic field impulses (DE 100 20 708 A1), a one-layer cylinder coil is coiled from rectangular copper wire braided with glass fiber and is surrounded by a copper tube with a longitudinal slit. The copper tube surrounding the coil is coated on its inner side with a polyimide film with increased heat conductivity for additional electrical insulation. In addition, the copper tube, as far as it surrounds the coil, is wrapped with a thick reinforcement made from para-aramide tread. This system made from copper coiling, slotted copper tube, and outer reinforcement is soaked with epoxy resin.
Such transformers with helically wound primary coils are mechanically very expensive to make. They are not constructed modularly. In addition, with these transformers, the high mechanical forces occurring with high currents between the primary and second coils are not compensated.
One object of the present invention is to provide a transformer, which is mechanically simple and cost-effective to produce, and which is formed, such that the high mechanical forces occurring between the primary coil and secondary part are compensated. The transformer, in addition, should be modularly constructed, and therefore, can be adapted to different applications.
This object is resolved with a transformer according to the present invention, in which the secondary part of the transformer comprises at least one electrically conductive plate, in which at least one cut-out penetrating the plate is disposed, which is provided with at least one slit originating from the cut-out, which separates the plate on one side of each cut-out into two parts and which produces the necessary bus bars, and wherein in rings about each cut-out, a primary coil with its bus bars can be electrically insulated in the plate.
The invention has the advantage that such a transformer can be made without an iron core with a very high transfer factor I2:I2>0.84 in a simple manner according to the power requirements with one or more plate-shaped secondary parts. The required secondary parts, therefore, can be made of plates with high electrical conductivity, such as copper, aluminum, or their alloys with chromium and/or zircon, for example, Cu Cr Zr-alloys, in which each individual plate is made with one or more, preferably circular cut-out and an annular groove surrounding each cut-out, in which, then, a flat, disk-shaped coil can be placed as the primary coil and encapsulated with insulating material.
The primary coil can be wound in a simple and most space-saving manner from the inside to the outside in the opposite direction, so that both bus bars can contact the primary coil on the outer circumference of the coil or winding.
This has the particular advantage that no return from the center of the coil is required, as with common coils. Such a return from the center of the coil produces necessary air gaps, which lead to a minimal coil tightness and, thus, the electrical coupling factor or the electrical efficiency of the transformer can be effected detrimentally, since in the air gaps, magnetic fields exist about the electrical conductor or the coil windings, whose flow lines do not go through the secondary part, thus leading to transfer loss with the production of the secondary current.
With the present invention, therefore, in particular, a high space factor of the coiling as a result of minimal parasitic air gaps between the primary and secondary parts is particularly advantageous.
Alternatively to the embodiment of the transformer of the present invention with an iron core, the transformer can be equipped also with an iron core. The iron can affect an improvement of the transfer factor, up to a determined current strength, which must be determined separately from case to case with measurement technologies, but runs with increasing current strength and exceeds a determined boundary flattened according to a characteristic line, which must be determined separately.
Instead of a primary coil made from a wire-type electrical conductor, magnetic coils according to DE 36 10 690 C2 can be used as the primary coil, which comprises multiple disks arranged in a stack and braced rigidly together with a central opening, whereby each disk has a radial slit originating from the central opening with electrical terminals arranged on both sides and includes an inner, ring-shaped region guiding the current as well as a heat conducting, outer region with further radial slits. The individual disks are connected in a spiral to one another in a series. This has the advantage of a particularly compact, high-duty structure with a high transfer factor and, therefore, a particularly favorable electrical efficiency.