Power generator comprising a transformer

• US 5,586,017 A
• Filed: 05/23/1995
• Issued: 12/17/1996
• Est. Priority Date: 05/27/1994
• Status: Expired due to Fees

• Current Assignee: US Philips Corporation (Koninklijke Philips N.V.)
• Original Assignee: US Philips Corporation (Koninklijke Philips N.V.)
• Inventors: Wimmer, Martin, Rohrbeck, Wolfgang, Negle, Hans
• Primary Examiner(s): Hecker, Stuart N.
• Assistant Examiner(s): Vu, Bao Q.
• Application Number:
  US08/447,598
• Time in Patent Office: 574 Days
• Field of Search: 363/39, 363/40, 363/44, 363/45, 363/46, 363/47, 315/411, 315/399, 315/405, 315/408, 315/400
• US Class Current: 363/39
• CPC Class Codes: H02M 3/01 Resonant DC/DC converters
• CPC Class Codes: H02M 3/33573 Full-bridge at primary side of an isolation transformer
• CPC Class Codes: H02P 25/032 Reciprocating, oscillating or vibrating motors
• CPC Class Codes: H05G 1/20 with high-frequency ac; with pulse trains pulse generators in general H03K3/00, H03K4/00
• CPC Class Codes: Y02B 70/10 Technologies improving the efficiency by using switched-mode power supplies [SMPS], i.e. efficient power electronics conversion e.g. power factor correction or reduction of losses in power supplies or efficient standby modes

Abstract

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.

Claims

1. A power generator, comprising 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, characterized in that

a) 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,

b) the resonance frequency of the series resonant circuit is lower than the resonance frequency of the parallel resonant circuit,

c) the resonant circuit formed by means of the primary winding arrangement is connected to an alternating voltage source which generates an essentially sinusoidal alternating current through the primary winding arrangement with an operating frequency in the range of the resonance frequency of the parallel resonant circuit.

2. A power generator as claimed in claim 1, characterized in that the primary winding arrangement forms part of a series resonant circuit which is connected to the alternating voltage source whose internal resistance is smaller, in an absolute sense, than the impedance of the primary winding arrangement at the operating frequency, and that the secondary winding arrangement forms part of a parallel resonant circuit.

3. A power generator as claimed in claim 2, characterized in that the coupling factor of the inductive coupling between the primary winding arrangement and the secondary winding arrangement is between 0.1 and 0.9.

4. A power generator as claimed in claim 2, characterized in that the characteristic impedance of the parallel resonant circuit is of the order of magnitude of the load resistance or more.

5. A power generator as claimed in claim 2, characterized in that the secondary winding arrangement comprises a plurality of series-connected sub-windings.

6. A power generator as claimed in claim 5, characterized in that the sub-windings are inductively coupled to one another.

7. A power generator as claimed in claim 2, characterized in that the operating frequency corresponds to a self-resonance frequency of the secondary winding arrangement.

8. A power generator as claimed in claim 2, characterized in that there is provided an additional parallel resonant circuit which is inductively coupled to the secondary winding arrangement and which is proportioned so that the secondary winding arrangement exhibits parallel resonance at the operating frequency.

9. A power generator as claimed in claim 8, characterized in that the additional winding is formed by a foil which is grounded at one point and is wound about one of the two winding arrangements so that it electrostatically shields it from the other winding arrangement.

10. A power generator as claimed in claim 7, characterized in that a ferromagnetic member which can be positioned relative to the secondary winding arrangement is provided for tuning purposes.

11. A power generator as claimed in claim 1, characterized in that the primary winding arrangement is connected to an alternating current generator and is complemented so as to form a parallel resonant circuit, and that the secondary winding arrangement forms part of a series resonant circuit whose characteristic resistance is substantially higher than the resistance of a load connected thereto.

12. A power generator as claimed in claim 1, characterized in that it is used in a high voltage generator of an X-ray generator.

13. A power generator as claimed in claim 3, characterized in that the characteristic impedance of the parallel resonant circuit is of the order of magnitude of the load resistance or more.

14. A power generator is claimed in claim 3, characterized in that the secondary winding arrangement comprises a plurality of series-connected sub-windings.

15. A power generator is claimed in claim 13, characterized in that the secondary winding arrangement comprises a plurality of series-connected sub-windings.

16. A power generator as claimed in claim 14, characterized in that the sub-windings are inductively coupled to one another.

17. A power generator as claimed in claim 15, characterized in that the sub-windings are inductively coupled to one another.

18. A power generator as claimed in claim 3, characterized in that the operating frequency corresponds to a self-resonance frequency of the secondary winding arrangement.

19. A power generator as claimed in claim 4, characterized in that the operating frequency corresponds to a self-resonance frequency of the secondary winding arrangement.

20. A power generator as claimed in claim 6, characterized in that the operating frequency corresponds to a self-resonance frequency of the secondary winding arrangement.