EP0126365A1 - Switch mode transformer for proportional control of static commutating elements - Google Patents

Switch mode transformer for proportional control of static commutating elements Download PDF

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Publication number
EP0126365A1
EP0126365A1 EP84105148A EP84105148A EP0126365A1 EP 0126365 A1 EP0126365 A1 EP 0126365A1 EP 84105148 A EP84105148 A EP 84105148A EP 84105148 A EP84105148 A EP 84105148A EP 0126365 A1 EP0126365 A1 EP 0126365A1
Authority
EP
European Patent Office
Prior art keywords
transformer
static
proportional control
windings
switch mode
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.)
Withdrawn
Application number
EP84105148A
Other languages
German (de)
French (fr)
Inventor
Michele Zambelli
Giovanni Maddalon
Doreano De Marco
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.)
ACC Compressors SpA
Original Assignee
Zanussi Elettromeccanica SpA
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 Zanussi Elettromeccanica SpA filed Critical Zanussi Elettromeccanica SpA
Publication of EP0126365A1 publication Critical patent/EP0126365A1/en
Withdrawn legal-status Critical Current

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    • HELECTRICITY
    • H01ELECTRIC ELEMENTS
    • H01FMAGNETS; INDUCTANCES; TRANSFORMERS; SELECTION OF MATERIALS FOR THEIR MAGNETIC PROPERTIES
    • H01F38/00Adaptations of transformers or inductances for specific applications or functions
    • H01F38/42Flyback transformers

Definitions

  • the present invention relates to a transformer of the so-called SMT (switch mode transformer) type, particularly for employ as a basic component for the proportional control of static commutating elements.
  • SMT switch mode transformer
  • the closed core is usually formed of two components connected to one another in a suitable manner and necessarily formed with windows for the passage of the transformer terminals. These windows are basically undesirable and therefore kept as small as possible.
  • an SMT transformer for proportional control of static commutating elements, comprising at least two primary windings and at least one secondary winding, by providing that the primary windings and the secondary winding(s) are formed respectively of metal strips wound, with interposition of an insulating film, on at least one portion of a per se known ferrite core of the open type.
  • the SMT transformer shown substantially comprises at least two primary windings 1 and at least one secondary winding 2 formed, in contrast to the windings of a conventional transformer, of a metal strip (3) preferably of aluminum, superimposed on an insulating film.
  • This technique for the formation of windings is per se known for instance from the field of coil-wound capacitors and from the manufacture of certain types of transformers, but has never as yet been employed in the manufacture of SMT transformers of the type under discussion, mainly because of the practical impossibility of forming a metal strip winding in combination with the use of a core of the "closed" type.
  • the closed core has formerly been thought to be indispensable in an SMT transformer for proportional control in order to minimize parasitic inductance and to thus ensure a satisfactory overall functioning.
  • the metal strips 3 constituting the primary windings 1 and secondary winding 2 are wound in a concentric arrangement with windings 4 of an insulating film interposed therebetween, on at least one portion (not visible in the drawing) of a ferrite core 5 of the open type.
  • ferrite core 5 comprises two substantially E-shaped portions 6 and 7 connected to one another in a mirror-symmetric arrangement, with the windings 1, 2 supported on the central legs.
  • the ferrite core may obviously have other shapes, for instance a C-shaped configuration.
  • the employ of an open core greatly simplifies the assembly of the various components of the transformer permitting such assembly to be readily and completely automatized.
  • the transformer according to the invention may of course be modified in any suitable manner within the scope of the basic characteristics of the present invention.

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  • Engineering & Computer Science (AREA)
  • Power Engineering (AREA)
  • Coils Or Transformers For Communication (AREA)

Abstract

© The invention relates to an SMT transformer for proportional control of static commutating elements. The primary (1) and secondary (2) windings of the transformer are formed by winding respective metal strips (3), superimposed on insulating film, around a portion of a ferrite core (5) of the open type.

Description

  • The present invention relates to a transformer of the so- called SMT (switch mode transformer) type, particularly for employ as a basic component for the proportional control of static commutating elements.
  • Granted that by "proportional control" one normally understands the condition under which the electronic control components associated with the primary winding of the transformer operate at a substantially constant load current/ /control current ratio, it is known that for satisfactory functioning of the entire circuit an SMT transformer has to ensure a reliable separation of the circuits while presenting a minimum parasitic inductance between its primary and secondary windings.
  • The circuit separation, required for safety reasons, is obtained by maintaining a substantially loose coupling between the windings which are usually formed of insulated copper wire. The loose coupling is at variance, however, with the requirement to minimize the parasitic inductance in the transformer so as to permit a rapid signal transmission between the windings free of spurious components and to thus ensure the correct control of the circuit associated to the transformer.
  • For minimizing the occurrence of parasitic, inductance in spite of the above noted loose coupling (required for safety reasons, as explained above) it is common practice to provide SMT transformers of the type under discussion with a "closed" ferrite core having an internal center core portion and an outer shield substantially enclosing the transformer. In this manner the magnetic flux always circulates within the ferrite core substantially without having to cross air gaps even externally of the transformer.
  • In practice, the closed core is usually formed of two components connected to one another in a suitable manner and necessarily formed with windows for the passage of the transformer terminals. These windows are basically undesirable and therefore kept as small as possible.
  • It is obvious that SMT transformers having a closed core present considerable difficulties as regards the formation of the windings, and in particular as regards the assembly of the.various components. These difficulties are such as to render the full automatization of the manufacture and assembly of the transformers impossible with all the resultant consequences with respect to productivity and economy.
  • It is therefore an object of the present invention to provide an SMT transformer of the type defined in the introduction, which present optimum safety and functional characteristics and permits its manufacture to be substantially simplified and readily automatized.
  • According to the invention, this object is attained in an SMT transformer for proportional control of static commutating elements, comprising at least two primary windings and at least one secondary winding, by providing that the primary windings and the secondary winding(s) are formed respectively of metal strips wound, with interposition of an insulating film, on at least one portion of a per se known ferrite core of the open type.
  • The characteristics and advantages of the invention will become more clearly evident from the following description of an exemplary embodiment with reference to the accompanying drawing, the only figure of which shows a partially sectioned perspective view of a preferred embodimetn of a transformer according to the invention.
  • The SMT transformer shown substantially comprises at least two primary windings 1 and at least one secondary winding 2 formed, in contrast to the windings of a conventional transformer, of a metal strip (3) preferably of aluminum, superimposed on an insulating film. This technique for the formation of windings is per se known for instance from the field of coil-wound capacitors and from the manufacture of certain types of transformers, but has never as yet been employed in the manufacture of SMT transformers of the type under discussion, mainly because of the practical impossibility of forming a metal strip winding in combination with the use of a core of the "closed" type. As ex- plaiend above, the closed core has formerly been thought to be indispensable in an SMT transformer for proportional control in order to minimize parasitic inductance and to thus ensure a satisfactory overall functioning.
  • According to a fundamental aspect of the invention, the metal strips 3 constituting the primary windings 1 and secondary winding 2 are wound in a concentric arrangement with windings 4 of an insulating film interposed therebetween, on at least one portion (not visible in the drawing) of a ferrite core 5 of the open type.
  • In the embodiment shown in the drawing, ferrite core 5 comprises two substantially E-shaped portions 6 and 7 connected to one another in a mirror-symmetric arrangement, with the windings 1, 2 supported on the central legs.
  • The ferrite core may obviously have other shapes, for instance a C-shaped configuration. In each case, the employ of an open core greatly simplifies the assembly of the various components of the transformer permitting such assembly to be readily and completely automatized.
  • As generally known, the employ of an open ferrite core in an SMT transformer of the type under discussion tends to increase the occurrence of parasitic inductance to a degree unaccceptable for the stated applications. In the transformer according to the invention, this phenomenon is unexpectedly compensated by the employ of metal strips for forming the windings.
  • As in fact found in practical experiments, the metal strips permit the formation of a more compact winding as compared to a conventional winding of copper wire, with a reduced dispersion of the magnetic flux, so as to compensate in optimum manner the hypothtical functional disadvantages deriving from the employ of an open core.
  • The transformer according to the invention may of course be modified in any suitable manner within the scope of the basic characteristics of the present invention.

Claims (1)

  1. An SMT transformer for proportional control of static commutating elements, comprising at least two primary windings and at least one secondary winding, characterized in that said primary windings (1) and said secondary winding(s) (2) are formed respectively of metal strips (3) wound, with the interposition of an insulating film, on at least one portion of a per se known ferrite core (5) of the open type.
EP84105148A 1983-05-09 1984-05-07 Switch mode transformer for proportional control of static commutating elements Withdrawn EP0126365A1 (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
IT4571483 1983-05-09
IT45714/83A IT1195595B (en) 1983-05-09 1983-05-09 SMT TRANSFORMER FOR PROPORTIONAL PILOTING OF STATIC SWITCHING POWER SUPPLIES

Publications (1)

Publication Number Publication Date
EP0126365A1 true EP0126365A1 (en) 1984-11-28

Family

ID=11257570

Family Applications (1)

Application Number Title Priority Date Filing Date
EP84105148A Withdrawn EP0126365A1 (en) 1983-05-09 1984-05-07 Switch mode transformer for proportional control of static commutating elements

Country Status (3)

Country Link
EP (1) EP0126365A1 (en)
ES (1) ES278940Y (en)
IT (1) IT1195595B (en)

Cited By (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE3546410A1 (en) * 1985-12-31 1987-07-02 Sikora Gernot Dipl Ing Fh Transformer
DE3546377A1 (en) * 1985-12-31 1987-07-09 Sikora Gernot Dipl Ing Fh Magnetic driver stage, especially for a power switching transistor, and a transformer for the driver stage
WO1987004297A1 (en) * 1985-12-31 1987-07-16 Gernot Sikora Magnetic driver stage and transformer, especially for the driver stage
EP0422397A1 (en) * 1989-10-11 1991-04-17 PROCOND ELETTRONICA S.p.A. Switch mode transformer
DE9115298U1 (en) * 1991-12-10 1992-02-13 Meßelektronik Dresden GmbH i.Ges.Vollstr., 01099 Dresden Foil power transformers, especially for electronic converters
CN105261468A (en) * 2015-11-05 2016-01-20 成都市亚丰电子技术有限责任公司 Flat high-voltage transformer and manufacturing method thereof

Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3611233A (en) * 1969-08-14 1971-10-05 Atomic Energy Commission Pulse transformer using stripline windings
US3617854A (en) * 1970-04-20 1971-11-02 Raytheon Co Pulse transformer
US3742332A (en) * 1971-03-04 1973-06-26 Siemens Ag Pulse transformer for driving thyristors

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3611233A (en) * 1969-08-14 1971-10-05 Atomic Energy Commission Pulse transformer using stripline windings
US3617854A (en) * 1970-04-20 1971-11-02 Raytheon Co Pulse transformer
US3742332A (en) * 1971-03-04 1973-06-26 Siemens Ag Pulse transformer for driving thyristors

Cited By (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE3546410A1 (en) * 1985-12-31 1987-07-02 Sikora Gernot Dipl Ing Fh Transformer
DE3546377A1 (en) * 1985-12-31 1987-07-09 Sikora Gernot Dipl Ing Fh Magnetic driver stage, especially for a power switching transistor, and a transformer for the driver stage
WO1987004297A1 (en) * 1985-12-31 1987-07-16 Gernot Sikora Magnetic driver stage and transformer, especially for the driver stage
EP0422397A1 (en) * 1989-10-11 1991-04-17 PROCOND ELETTRONICA S.p.A. Switch mode transformer
DE9115298U1 (en) * 1991-12-10 1992-02-13 Meßelektronik Dresden GmbH i.Ges.Vollstr., 01099 Dresden Foil power transformers, especially for electronic converters
CN105261468A (en) * 2015-11-05 2016-01-20 成都市亚丰电子技术有限责任公司 Flat high-voltage transformer and manufacturing method thereof

Also Published As

Publication number Publication date
IT8345714A1 (en) 1984-11-09
ES278940Y (en) 1985-04-01
IT8345714A0 (en) 1983-05-09
IT1195595B (en) 1988-10-19
ES278940U (en) 1984-09-16

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PUAI Public reference made under article 153(3) epc to a published international application that has entered the european phase

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AK Designated contracting states

Designated state(s): AT BE CH DE FR GB IT LI LU NL SE

17P Request for examination filed

Effective date: 19850417

17Q First examination report despatched

Effective date: 19860220

STAA Information on the status of an ep patent application or granted ep patent

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18D Application deemed to be withdrawn

Effective date: 19860704

RIN1 Information on inventor provided before grant (corrected)

Inventor name: MADDALON, GIOVANNI

Inventor name: DE MARCO, DOREANO

Inventor name: ZAMBELLI, MICHELE