U.S. Philips Corporation

Martin Wimmer

Hans Negle

Heinz Willi Van Der Broeck

Christoph Loef

Bernhard Wagner

Arne Lunding

Diethard A Peter

Alfred Sachsse

Reinhard V Hacht

Wolfgang Rohrbeck

In an X-ray device which includes an X-ray tube (12) provided with means (15, 22, 23) for influencing the electron flow through the X-ray tube (12), a control voltage for the means for influencing the electron flow is customarily generated by means of a complex circuit which, because of its size, is not suitable to be accommodated within the protective tube housing. This has the drawback that the control voltage for the X-ray tube, usually of high voltage potential, must be supplied additionally to the high-voltage supply. Therefore, it is desirable to realize a simple generation means the control voltage which is suitable for accommodation in the protective tube housing. To this end, the invention proposes a piezoelectric transformer (21, 24, 25) for generating the control voltage for the X-ray tube. The invention also relates to a piezoelectric transformer which is particularly suitable for generating such a control voltage.

X-ray device including a piezoelectric transformer

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

A high-voltage generator, includes a rectifier circuit (9) and a measuring resistor arrangement (8) for forming a measuring voltage (U.sub.M) which is proportional to the direct voltage (U.sub.DC), the measuring resistor arrangement (8) comprising at least one associated measuring resistor (R.sub.1, R.sub.2, R.sub.3) for each rectifier stage (31, 32, 33). In order to achieve a cost-saving and notably space-saving construction with adequate shielding of the measuring resistors (R.sub.1, R.sub.2, R.sub.3) from parts of the circuit (C.sub.4 . . . C.sub.9, 1, 2, 3) carrying the alternating voltage and from ground potential, the measuring resistors (R.sub.1, R.sub.2, R.sub.3) are integrated in the associated rectifier stages (31, 32, 33) and enclosed by a shield (11, 12, 13) which carries the direct voltage potential of the associated rectifier stage (31, 32, 33).

High-voltage generator with shielded measuring resistors

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 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.

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Bad Oldesloe, Germany

Martin Wimmer