U.S. Philips Corporation

Koninklijke Philips Corporation N.v.

Hans Negle

Martin Wimmer

Bernd Freiheit-Jensen

Alfred Sachsse

Christoph Loef

Heinz Willi Van Der Broeck

Bernhard Wagner

Heinz Mester

Arne Lunding

Bernd Hermeyer

Bernd Wandler

Wolfgang Rohrbeck

High voltage insulating materials in solid and liquid form which are provided in particular for use in high voltage generators for example for radiotechnology and computer tomography. The solid insulating materials are characterized in particular in that they have a high dielectric strength while having a relatively low weight. Furthermore, the electrical conductivity of the insulating materials can be set relatively simply such that surface charges are reliably dissipated and voltage flashovers are avoided. Finally, with further embodiments, in particular in the case of hybrid insulating materials, it is possible to adapt or change the dielectric constant and/or the electrical conductivity of the insulating materials in a targeted manner such that the respective voltage drops over the insulting materials do not exceed the dielectric strength thereof.

High voltage insulating materials

Vacuum filled hollow alveoles embedded in an insulation material in order to arrive at a light weight insulation material using the high breakdown voltage of evacuated cavities, i.e. alveoles at a vacuum lower than the minimum of the Paschen law. Pressurized hollow alveoles embedded in an insulation material in order to arrive at a light weight insulation material using the high breakdown voltage of pressurized cavities, i.e. alveoles at a pressure higher than the minimum of the Paschen law.

Insulator material and method for manufacturing thereof

A high field/high voltage unit comprising at least one electrical component () and a solid insulating material () in the form of a first and a second piece part () which form, in particular, hard foam half bodies and a method of manufacturing same is disclosed. The piece parts () each have an inner structure comprising a plurality of preformed cavities () in which electrical components () are fixed. After assembly, the piece parts () form a closed casing of the high field/high voltage unit so that no extra steel vessel is necessary. Conductive paths () for the interconnection of the components are integrated into the insulating material () using for example an insert technology. Since several functions can thus be integrated into the solid insulating material (), a simple solution for assembling and disassembling an oil/gas filled high field/high voltage unit like a high voltage generator for an X-ray tube is realized.

Electrical high field/high voltage unit and method of manufacturing same

A description is given of a high-voltage connector having a plug with a rubber cone () for insertion into a coupling socket (). Such a connector is also referred to as a rubber cone plug system and serves in particular to connect X-ray radiators with high-voltage generators. The connector is noteworthy in particular in that the length of the rubber cone () is dimensioned such that, in the inserted state, there remains an expansion space () between an end face of the rubber cone () and a bottom of the coupling socket (), into which expansion space () the rubber cone () can thermally expand. A particular advantage of this design lies in the fact that, by virtue of the thermal changes on account of highly fluctuating operating temperatures of the connected devices, the high-voltage strength is not impaired even after a large number of such temperature cycles.

High-voltage connector

The invention relates to an X-ray tube which includes a device for at least substantially protecting an object to be examined against the incidence of undesirable X-rays (E) which can be produced notably by the decay of a residual or surplus charge present in a high-voltage circuit after an X-ray exposure. To this end there is provided at least one device () for deflecting and/or defocusing the electron beam (E) produced by the residual and/or surplus charge in such a manner that at least it is not incident to a significant extent on a region () of an anode () wherefrom X-rays excited thereby are directed towards an object to be examined.

X-ray tube

The invention relates to a high-voltage generator which is proportioned so as to realize a particularly low weight in combination with a high output power and is suitable notably for use in rotating X-ray systems such as computed tomography apparatus. To this end, the high-voltage generator is provided with a hybrid insulation which is formed as far as possible by a high resistance foam ( to ) and an insulating liquid ( ). The foam is shaped and arranged in such a manner that there are formed channels ( to ) wherethrough the insulating liquid ( ) can flow in areas requiring a discharge of heat or an electric strength stronger than can be endured by the high- resistance foam alone.

High-voltage generator provided with a hybrid insulation

The invention relates to a high-voltage connector, consisting of a plug member and a receptacle member receiving the plug member, the area of the plug member facing the receptacle member and/or the area of the receptacle member facing the plug member being provided with a layer of an elastomer. A particularly high high-voltage strength is achieved in that the elastomer is made to swell by means of a swelling medium. The invention also relates to an X-ray generator comprising such a high-voltage connector and to a method of manufacturing such a high-voltage connector.

An X-ray apparatus includes an X-ray source with an X-ray tube (2) arranged in a protective tube housing (1) and a filament converter which is connected to the cathode (3) of the X-ray tube (2) and accommodated in the protective tube housing (1). Because of its volume, the filament converter usually cannot be accommodated in the protective tube housing (1) of conventional X-ray apparatus unless major structural modifications are made. However, the use of attenuated high-voltage cables at the cathode side is then impossible still. The invention utilizes a filament converter in the form of a coreless filament transformer (14, 15, 16, 17) and the primary coil (14, 16) of the filament transformer is arranged so as to be coaxial with the secondary coil (15, 17) of the filament transformer. Moreover, the two coils are arranged around a carrier (5, 10), which is preferably the high-voltage connection socket (10) or the tube neck (5). This is an inexpensive and structurally simple solution which enables integration of the filament converter in the protective tube housing (1) in conventional X-ray apparatus.

X-ray apparatus

An X-ray apparatus, includes a power supply section for powering an X-ray tube (4) with a high-voltage transformer (3) which has two groups of primary and secondary windings provided on the same transformer core, the coupling between the primary windings (16, 26) belonging to different groups being weaker than the coupling between primary and secondary windings (for example, 16, 31) belonging to the same group, the primary windings of the two groups being connected to two inverters (1, 2) which operate at the same frequency. Control of the power at the secondary side is improved in that the inverters are operated at a fixed frequency and with a duty cycle which can be independently controlled.

X-ray apparatus comprising a power supply section for powering an X-ray

A power generator, including a transformer with a primary winding arrangement and a secondary winding arrangement which is inductively coupled thereto, the primary winding arrangement forming a resonant circuit in conjunction with a capacitor, and a load being connected to the secondary winding arrangement. Therein, one winding arrangement of the transformer forms part of a series resonant circuit and, the other winding arrangement forms part of a parallel resonant circuit, the resonance frequency of the series resonant circuit is lower than the resonance frequency of the parallel resonant circuit, and the primary winding is connected to an alternating voltage generator so that an essentially sinusoidal alternating current flows through the primary winding.

Power generator comprising a transformer

A high-voltage unit comprising at least a high-voltage electrode which carries a high voltage in the operating condition of the high-voltage unit. A measuring divider/resistor arrangement is connected between the high-voltage electrode and a measuring point wherefrom a measuring voltage is derived corresponding to the variation in time of the high voltage. A reduced volume and thus a more compact device is achieved in that a flat measuring electrode is provided which carries the potential of the measuring point and in that the measuring divider/resistor arrangement is positioned between the high-voltage electrode and the measuring electrode so that it is inclined relative to each of these electrodes.

High-voltage unit comprising a measuring divider/resistor arrangement

A high-voltage transformer, for an X-ray apparatus includes a high-voltage winding (4) which consists of at least one coil (5) which is supported by an insulating member (6). Heat dissipation from the coil is improved in that the coil is wound so as to be self-supporting and have a stable shape without requiring the use of supporting members and/or intermediate insulating elements, a small part of its surface being connected to the insulating member so that the greatest part of its surface is situated a distance from the walls of the insulating member.

High voltage transformer, notably for an X-ray apparatus

An X-ray generator for operating an X-ray tube having parts of the tube connected to ground includes a high-voltage transformer arrangement having distinct secondary windings for producing positive and negative high voltages, for the anode and the cathode, respectively, of the X-ray tube. The unfavorable voltage distribution inherent in the feeding of such an X-ray tube by a high-ohmic generator is removed in a simple manner in that the secondary windings are each associated with a primary winding and that in series with the primary winding for producing the anode voltage an inductance is connected by means of a switching device.

X-ray generator for operating an X-ray tube with parts of the tube

A high-voltage measuring device includes a grounded, cylindrical outer electrode (1) and an inner coaxial electrode (2) which has an at least approximately cylindrical shape and carries a high-voltage potential. A non-flat high-voltage resistor (3) which is arranged coaxially with respect to the inner electrode and is connected thereto. This resistor extends at least as far as the vicinity of the outer electrode. The response bandwidth and the loadability of the device substantially improved in that the high-voltage resistor is a cone shape envelope of uniform thickness such that the potential variation in response to current flow through the resistor corresponds to the electrostatic potential variation at least at the area of the inner electrode.

High voltage measuring device

The invention relates to a measuring and damping resistor arrangement for a high-voltage apparatus. The measuring resistor arrangement preferably includes several series-connected resistors which are arranged on a support and which are capacitively bridged and is electrostatically shielded by a damping resistor arrangement. Preferably, the damping resistor arrangement is formed by a resistance wire wound onto an insulating body which encloses a part of the measuring resistor arrangement at the high-voltage side.

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Nahe, Germany

Hans Negle