EP0487767B1 - High frequency X-ray generator - Google Patents

High frequency X-ray generator Download PDF

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Publication number
EP0487767B1
EP0487767B1 EP90122684A EP90122684A EP0487767B1 EP 0487767 B1 EP0487767 B1 EP 0487767B1 EP 90122684 A EP90122684 A EP 90122684A EP 90122684 A EP90122684 A EP 90122684A EP 0487767 B1 EP0487767 B1 EP 0487767B1
Authority
EP
European Patent Office
Prior art keywords
resonant circuit
ray generator
voltage
frequency
capacitor
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired - Lifetime
Application number
EP90122684A
Other languages
German (de)
French (fr)
Other versions
EP0487767A1 (en
Inventor
Otto Dipl.-Ing. Ebersberger (Fh)
Werner Dipl.-Ing. Brandstätter
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Siemens AG
Original Assignee
Siemens AG
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Siemens AG filed Critical Siemens AG
Priority to EP90122684A priority Critical patent/EP0487767B1/en
Priority to DE90122684T priority patent/DE59003559D1/en
Priority to US07/770,247 priority patent/US5155754A/en
Priority to JP1991103375U priority patent/JP2532179Y2/en
Publication of EP0487767A1 publication Critical patent/EP0487767A1/en
Application granted granted Critical
Publication of EP0487767B1 publication Critical patent/EP0487767B1/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

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Classifications

    • H—ELECTRICITY
    • H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
    • H05G—X-RAY TECHNIQUE
    • H05G1/00—X-ray apparatus involving X-ray tubes; Circuits therefor
    • H05G1/08—Electrical details
    • H05G1/10—Power supply arrangements for feeding the X-ray tube
    • H05G1/20—Power supply arrangements for feeding the X-ray tube with high-frequency ac; with pulse trains
    • H—ELECTRICITY
    • H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
    • H05G—X-RAY TECHNIQUE
    • H05G1/00—X-ray apparatus involving X-ray tubes; Circuits therefor
    • H05G1/08—Electrical details
    • H05G1/26—Measuring, controlling or protecting
    • H05G1/30—Controlling
    • H05G1/32—Supply voltage of the X-ray apparatus or tube

Definitions

  • the invention relates to a high-frequency X-ray generator with two resonant circuit inverters fed by a DC voltage source, each of which contains a resonant circuit capacitor and each feeds a high-voltage transformer, an X-ray tube being connected to two high-voltage rectifiers connected in series and each high-voltage rectifier being fed by one of the high-voltage transformers.
  • a high-frequency X-ray generator is known from DE-A-2 814 320.
  • an x-ray tube with a metal middle part can be used as the x-ray tube, which is connected to the connecting line between the two high-voltage rectifiers.
  • the invention has for its object to design a high-frequency X-ray generator of the type mentioned so that this shift of the center of the high voltage is avoided.
  • This object is achieved in that the resonant circuit impedances are different. If the capacitance of the resonant circuit capacitor of the cathode-side inverter is increased in comparison to the capacitance of the resonant circuit capacitor of the anode-side inverter, then, if appropriate Dimensioning of the current flowing through the metal middle part can be compensated.
  • a further development of the invention is that the capacity of one of the resonant circuits can be switched over.
  • the high-voltage X-ray generator can be used both in connection with an X-ray tube without a metal middle part and in connection with an X-ray tube with a metal middle part.
  • two capacitors with the same capacitance are chosen, in the second case the capacitors are chosen differently.
  • FIG. 1 shows an X-ray tube 1 with a metal middle part 2, which is connected with its anode to the positive pole of a high-voltage rectifier 3 and with its cathode to the negative pole of a high-voltage rectifier 4.
  • the high-voltage rectifiers 3, 4 are connected in series via a measuring resistor 5.
  • the metal middle part 2 is connected to the negative pole of the high-voltage rectifier 3.
  • An inverter 6, 7 is assigned to each high-voltage rectifier 3, 4.
  • the inverters 6, 7 are fed by a DC voltage source 8.
  • Each high-voltage rectifier 3, 4 is preceded by a high-voltage transformer 9, 10 (FIGS. 2 to 4) fed by the corresponding inverter 6, 7.
  • two capacitors 13, 14 are provided in the cathode-side inverter.
  • the capacitor 13 has the same capacitance as the capacitor 11 and is used alone when an X-ray tube without a metal middle part is used.
  • the capacitor 14 is switched on by a switch 15, as a result of which the capacitance of the resonant circuit of the cathode-side inverter 7 is increased.
  • the circuit according to FIG. 3 can accordingly be used optionally for an X-ray tube with or without a metal middle part.
  • the cathode-side inverter 7a has two separately controllable half bridges 16, 17.
  • the half bridge 16 is used when using an X-ray tube without a metal middle part and only switches on the capacitor 13, while when using an X-ray tube with Metal middle part for switching on both capacitors 13, 14, both half bridges 16, 17 are controlled synchronously. It is also possible in this case to control only the half bridge 17 and to switch off the capacitor 13 completely if the capacitor 14 has a correspondingly high capacitance.

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  • Health & Medical Sciences (AREA)
  • General Health & Medical Sciences (AREA)
  • Toxicology (AREA)
  • X-Ray Techniques (AREA)

Description

Die Erfindung betrifft einen Hochfrequenz-Röntgengenerator mit zwei von einer Gleichspannungsquelle gespeisten Schwingkreiswechselrichtern, von denen jeder je einen Schwingkreiskondensator enthält und jeder je einen Hochspannungstransformator speist, wobei eine Röntgenröhre an zwei in Reihe geschalteten Hochspannungsgleichrichtern angeschlossen ist und jeder Hochspannungsgleichrichter von einem der Hochspannungstransformatoren gespeist wird. Ein solcher Hochfrequenz-Röntgengenerator ist aus DE-A-2 814 320 bekannt.The invention relates to a high-frequency X-ray generator with two resonant circuit inverters fed by a DC voltage source, each of which contains a resonant circuit capacitor and each feeds a high-voltage transformer, an X-ray tube being connected to two high-voltage rectifiers connected in series and each high-voltage rectifier being fed by one of the high-voltage transformers. Such a high-frequency X-ray generator is known from DE-A-2 814 320.

Als Röntgenröhre kann bei einem derartigen Hochfrequenz-Röntgengenerator eine Röntgenröhre mit Metallmittelteil verwendet werden, welches mit der Verbindungsleitung zwischen den beiden Hochspannungsgleichrichtern verbunden ist. Dabei fließt ein Strom über das Metallmittelteil ab, der für die Hochspannungsseite des Röntgengenerators eine zusätzliche Belastung darstellt.In such a high-frequency x-ray generator, an x-ray tube with a metal middle part can be used as the x-ray tube, which is connected to the connecting line between the two high-voltage rectifiers. A current flows through the metal middle part, which represents an additional load for the high voltage side of the X-ray generator.

Bei einem Hochfrequenz-Röntgengenerator der genannten Art, bei dem die Hochspannungstransformatoren primärseitig nicht starr verbunden sind, sondern jeweils von einem eigenen Wechselrichter versorgt werden, kommt es durch den Strom vom Metallmittelteil zu einer Verschiebung des Mittelpunktes der Hochspannung.In the case of a high-frequency X-ray generator of the type mentioned, in which the high-voltage transformers are not rigidly connected on the primary side, but are each supplied by their own inverter, the current from the metal center part causes the center point of the high voltage to shift.

Der Erfindung liegt die Aufgabe zugrunde, einen Hochfrequenz-Röntgengenerator der eingangs genannten Art so auszubilden, daß diese Verschiebung des Mittelpunktes der Hochspannung vermieden ist.The invention has for its object to design a high-frequency X-ray generator of the type mentioned so that this shift of the center of the high voltage is avoided.

Diese Aufgabe ist erfindungsgemäß dadurch gelöst, daß die Schwingkreisimpedanzen unterschiedlich sind. Wird die Kapazität des Schwingkreiskondensators des kathodenseitigen Wechselrichters im Vergleich zur Kapazität des Schwingkreiskondensators des anodenseitigen Wechselrichters vergrößert, so kann bei entsprechender Dimensionierung der über das Metallmittelteil abfließende Strom kompensiert werden.This object is achieved in that the resonant circuit impedances are different. If the capacitance of the resonant circuit capacitor of the cathode-side inverter is increased in comparison to the capacitance of the resonant circuit capacitor of the anode-side inverter, then, if appropriate Dimensioning of the current flowing through the metal middle part can be compensated.

Eine Weiterbildung der Erfindung besteht darin, daß die Kapazität eines der Schwingkreise umschaltbar ist. Auf diese Weise ist der Hochspannungs-Röntgengenerator sowohl in Verbindung mit einer Röntgenröhre ohne Metallmittelteil als auch in Verbindung mit einer Röntgenröhre mit Metallmittelteil einsetzbar. Im ersteren Falle werden zwei Kondensatoren mit gleicher Kapazität gewählt, im zweiten Falle werden die Kapazitäten unterschiedlich gewählt.A further development of the invention is that the capacity of one of the resonant circuits can be switched over. In this way, the high-voltage X-ray generator can be used both in connection with an X-ray tube without a metal middle part and in connection with an X-ray tube with a metal middle part. In the first case, two capacitors with the same capacitance are chosen, in the second case the capacitors are chosen differently.

Die Erfindung ist nachfolgend anhand der Zeichnung näher erläutert. Es zeigen:

Fig. 1
die für die Erfindung wesentlichen Teile eines Hochfrequenz-Röntgengenerators zur Erläuterung des Erfindungsgedankens, und
Fig. 2 bis 4
verschiedene Ausführungsformen der Wechselrichterschaltung bei dem Hochfrequenz-Röntgengenerator gemäß Fig. 1.
The invention is explained below with reference to the drawing. Show it:
Fig. 1
the parts of a high-frequency X-ray generator essential for the invention to explain the inventive concept, and
2 to 4
Various embodiments of the inverter circuit in the high-frequency x-ray generator according to FIG. 1.

In der Fig. 1 ist eine Röntgenröhre 1 mit Metallmittelteil 2 dargestellt, welche mit ihrer Anode mit dem Pluspol eines Hochspannungsgleichrichters 3 und mit ihrer Kathode mit dem Minuspol eines Hochspannungsgleichrichters 4 verbunden ist. Die Hochspannungsgleichrichter 3, 4 sind über einen Meßwiderstand 5 in Reihe geschaltet. Das Metallmittelteil 2 ist mit dem Minuspol des Hochspannungsgleichrichters 3 verbunden.1 shows an X-ray tube 1 with a metal middle part 2, which is connected with its anode to the positive pole of a high-voltage rectifier 3 and with its cathode to the negative pole of a high-voltage rectifier 4. The high-voltage rectifiers 3, 4 are connected in series via a measuring resistor 5. The metal middle part 2 is connected to the negative pole of the high-voltage rectifier 3.

Jedem Hochspannungsgleichrichter 3, 4 ist jeweils ein Wechselrichter 6, 7 zugeordnet. Die Wechselrichter 6, 7 werden von einer Gleichspannungsquelle 8 gespeist. Jedem Hochspannungsgleichrichter 3, 4 ist jeweils ein vom entsprechenden Wechselrichter 6, 7 gespeister Hochspannungstransformators 9, 10 (Fig. 2 bis 4) vorgeschaltet.An inverter 6, 7 is assigned to each high-voltage rectifier 3, 4. The inverters 6, 7 are fed by a DC voltage source 8. Each high-voltage rectifier 3, 4 is preceded by a high-voltage transformer 9, 10 (FIGS. 2 to 4) fed by the corresponding inverter 6, 7.

In der Fig. 2 ist gezeigt, daß die Hochspannungstransformatoren 9, 10 zusammen mit Kondensatoren 11, 12 Reihenschwingkreise bilden, die in einer Diagonale des jeweiligen Wechselrichters 6, 7 liegen. Die Kapazität des Kondensators 12 des kathodenseitigen Wechselrichters 7 ist größer als die Kapazität des Kondensators 11 des anodenseitigen Wechselrichters 6. Dadurch wird in der geschilderten Weise der vom Metallmittelteil 2 abfließende Strom kompensiert.2 shows that the high-voltage transformers 9, 10 together with capacitors 11, 12 form series resonant circuits which lie in a diagonal of the respective inverter 6, 7. The capacitance of the capacitor 12 of the cathode-side inverter 7 is greater than the capacitance of the capacitor 11 of the anode-side inverter 6. As a result, the current flowing off from the metal center part 2 is compensated for.

Bei dem Ausführungsbeispiel gemäß Fig. 3 sind im kathodenseitigen Wechselrichter zwei Kondensatoren 13, 14 vorgesehen. Der Kondensator 13 hat dabei dieselbe Kapazität wie der Kondensator 11 und wird allein verwendet, wenn eine Röntgenröhre ohne Metallmittelteil benutzt wird. Bei Verwendung einer Röntgenröhre mit Metallmittelteil, wie es in Fig. 1 dargestellt ist, wird der Kondensator 14 durch einen Schalter 15 zugeschaltet, wodurch die Kapazität des Schwingkreises des kathodenseitigen Wechselrichters 7 vergrößert wird. Die Schaltung gemäß Fig. 3 ist demgemäß wahlweise für eine Röntgenröhre mit oder ohne Metallmittelteil benutzbar.3, two capacitors 13, 14 are provided in the cathode-side inverter. The capacitor 13 has the same capacitance as the capacitor 11 and is used alone when an X-ray tube without a metal middle part is used. When using an X-ray tube with a metal middle part, as shown in FIG. 1, the capacitor 14 is switched on by a switch 15, as a result of which the capacitance of the resonant circuit of the cathode-side inverter 7 is increased. The circuit according to FIG. 3 can accordingly be used optionally for an X-ray tube with or without a metal middle part.

Das gleiche gilt für die Schaltung gemaß Fig. 4. Hier besitzt der kathodenseitige Wechselrichter 7a zwei getrennt ansteuerbare Halbbrücken 16, 17. Die Halbbrücke 16 wird bei Verwendung einer Röntgenröhre ohne Metallmittelteil benutzt und schaltet nur den Kondensator 13 ein, während bei Benutzung einer Röntgenröhre mit Metallmittelteil zur Einschaltung beider Kondensatoren 13, 14 beide Halbbrücken 16, 17 synchron angesteuert werden. Es ist auch möglich, in diesem Fall nur die Halbbrücke 17 anzusteuern und den Kondensators 13 ganz abzuschalten, wenn der Kondensator 14 eine entsprechend hohe Kapazität hat.The same applies to the circuit according to FIG. 4. Here, the cathode-side inverter 7a has two separately controllable half bridges 16, 17. The half bridge 16 is used when using an X-ray tube without a metal middle part and only switches on the capacitor 13, while when using an X-ray tube with Metal middle part for switching on both capacitors 13, 14, both half bridges 16, 17 are controlled synchronously. It is also possible in this case to control only the half bridge 17 and to switch off the capacitor 13 completely if the capacitor 14 has a correspondingly high capacitance.

Claims (4)

  1. High-frequency X-ray generator having two resonant circuit inverters (6, 7) which are fed by a direct voltage source (8) and each of which contains a respective resonant circuit capacitor (11, 12) and feeds a respective high-voltage transformer (9, 10), with an X-ray tube (1) being connected to two high-voltage rectifiers (3, 4) which are connected in series and with each high-voltage rectifier (3, 4) being fed by one of the high-voltage transformers (9, 10), characterised in that the resonant circuit impedances are different.
  2. High-frequency X-ray generator according to claim 1, characterised in that the resonant circuit capacitor (12, 14) of the cathode-side inverter (7, 7a) has a greater capacitance than the resonant circuit capacitor (11) of the anode-side inverter (6).
  3. High-frequency X-ray generator according to claim 2, characterised in that the resonant circuit capacitance of one of the inverters (7, 7a) can be switched over.
  4. High-frequency X-ray generator according to claim 3, characterised in that one resonant circuit has two different capacitors (13, 14) which are connected to two inverter half-bridges (16, 17) which can be activated separately.
EP90122684A 1990-11-27 1990-11-27 High frequency X-ray generator Expired - Lifetime EP0487767B1 (en)

Priority Applications (4)

Application Number Priority Date Filing Date Title
EP90122684A EP0487767B1 (en) 1990-11-27 1990-11-27 High frequency X-ray generator
DE90122684T DE59003559D1 (en) 1990-11-27 1990-11-27 High frequency x-ray generator.
US07/770,247 US5155754A (en) 1990-11-27 1991-10-03 High frequency supply for an x-ray tube
JP1991103375U JP2532179Y2 (en) 1990-11-27 1991-11-20 High frequency X-ray generator

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
EP90122684A EP0487767B1 (en) 1990-11-27 1990-11-27 High frequency X-ray generator

Publications (2)

Publication Number Publication Date
EP0487767A1 EP0487767A1 (en) 1992-06-03
EP0487767B1 true EP0487767B1 (en) 1993-11-18

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EP90122684A Expired - Lifetime EP0487767B1 (en) 1990-11-27 1990-11-27 High frequency X-ray generator

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US (1) US5155754A (en)
EP (1) EP0487767B1 (en)
JP (1) JP2532179Y2 (en)
DE (1) DE59003559D1 (en)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE19631143C2 (en) * 1996-08-01 2003-03-20 Siemens Ag High-frequency X-ray generator

Families Citing this family (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2634369B2 (en) * 1993-07-15 1997-07-23 浜松ホトニクス株式会社 X-ray equipment
DE4443551A1 (en) * 1994-12-07 1996-06-20 Philips Patentverwaltung Arrangement for supplying power to an electrical consumer, in particular an X-ray apparatus
JP2003142294A (en) * 2001-10-31 2003-05-16 Ge Medical Systems Global Technology Co Llc High voltage generating circuit and x-ray generating device

Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE2814320A1 (en) * 1978-04-03 1979-10-11 Siemens Ag ROYAL DIAGNOSTIC GENERATOR WITH AN INVERTER FEEDING ITS HIGH VOLTAGE TRANSFORMER

Family Cites Families (12)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE2802513C2 (en) * 1978-01-20 1983-10-06 Siemens Ag, 1000 Berlin Und 8000 Muenchen X-ray diagnostic generator with an inverter feeding its high-voltage transformer, to which an LC resonant circuit is assigned
DE2831093A1 (en) * 1978-07-14 1980-01-24 Siemens Ag X-RAY DIAGNOSTIC GENERATOR
FR2507842A1 (en) * 1981-06-12 1982-12-17 Gen Equip Med Sa SEMICONDUCTOR VOLTAGE REGULATOR AND RADIOLOGY GENERATOR COMPRISING SUCH A REGULATOR
DE3135061A1 (en) * 1981-09-04 1983-03-24 Philips Patentverwaltung Gmbh, 2000 Hamburg X-RAY GENERATOR FOR THE OPERATION OF X-RAY TUBES WITH A MEANS CONNECTED TO GROUND
DE3218535A1 (en) * 1982-05-17 1983-11-17 Philips Patentverwaltung HIGH VOLTAGE GENERATOR, ESPECIALLY FOR THE SUPPLY OF A X-RAY TUBE
SE438109B (en) * 1983-11-28 1985-04-01 Esab Ab STROMKELLA FOR LIGHT REAR WELDING
DE3437064A1 (en) * 1984-10-09 1986-04-10 Siemens AG, 1000 Berlin und 8000 München Medium-frequency X-ray generator
DE3567351D1 (en) * 1984-10-09 1989-02-09 Siemens Ag Medium-frequency x-ray generator power supply
DE3625855A1 (en) * 1986-07-31 1988-02-04 Siemens Ag Medium-frequency X-ray diagnosis generator
US4807269A (en) * 1987-04-02 1989-02-21 Grady John K Apparatus for powering x-ray tubes
JPS6489198A (en) * 1987-09-30 1989-04-03 Toshiba Corp X-ray high-voltage device
DE3900146A1 (en) * 1988-01-08 1989-07-20 Toshiba Kawasaki Kk Power supply device for an X-ray CT scanner

Patent Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE2814320A1 (en) * 1978-04-03 1979-10-11 Siemens Ag ROYAL DIAGNOSTIC GENERATOR WITH AN INVERTER FEEDING ITS HIGH VOLTAGE TRANSFORMER

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE19631143C2 (en) * 1996-08-01 2003-03-20 Siemens Ag High-frequency X-ray generator

Also Published As

Publication number Publication date
US5155754A (en) 1992-10-13
EP0487767A1 (en) 1992-06-03
JPH0499700U (en) 1992-08-28
JP2532179Y2 (en) 1997-04-09
DE59003559D1 (en) 1993-12-23

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