EP0343886A2 - Disposition de circuit - Google Patents

Disposition de circuit Download PDF

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Publication number
EP0343886A2
EP0343886A2 EP89305127A EP89305127A EP0343886A2 EP 0343886 A2 EP0343886 A2 EP 0343886A2 EP 89305127 A EP89305127 A EP 89305127A EP 89305127 A EP89305127 A EP 89305127A EP 0343886 A2 EP0343886 A2 EP 0343886A2
Authority
EP
European Patent Office
Prior art keywords
core
winding
secondary winding
wound
transformer
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Withdrawn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
EP89305127A
Other languages
German (de)
English (en)
Other versions
EP0343886A3 (fr
Inventor
Stephen Mark Iskander
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.)
Teledyne UK Ltd
Original Assignee
EEV Ltd
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 EEV Ltd filed Critical EEV Ltd
Publication of EP0343886A2 publication Critical patent/EP0343886A2/fr
Publication of EP0343886A3 publication Critical patent/EP0343886A3/fr
Withdrawn legal-status Critical Current

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Classifications

    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01F—MAGNETS; INDUCTANCES; TRANSFORMERS; SELECTION OF MATERIALS FOR THEIR MAGNETIC PROPERTIES
    • H01F27/00—Details of transformers or inductances, in general
    • H01F27/34—Special means for preventing or reducing unwanted electric or magnetic effects, e.g. no-load losses, reactive currents, harmonics, oscillations, leakage fields
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01F—MAGNETS; INDUCTANCES; TRANSFORMERS; SELECTION OF MATERIALS FOR THEIR MAGNETIC PROPERTIES
    • H01F30/00—Fixed transformers not covered by group H01F19/00
    • H01F30/06—Fixed transformers not covered by group H01F19/00 characterised by the structure
    • H01F30/16—Toroidal transformers

Definitions

  • This invention relates to circuit arrangements and more particularly, but not exclusively, to arrangements including a transformer in which current passed through a primary winding is used to drive a load, such as a magenetron, connected across a secondary winding.
  • a circuit arrangement which is conventionally used for driving a magnetron is illustrated in Figure 1. It includes a pulse transformer 1 having a core 2 about which is wound a primary winding 3 and a secondary winding 4.
  • the primary winding 3 is connected to a d.c. charging circuit indicated generally at 5 which includes a switch 6 for controlling transmission of current pulses through the primary winding 3.
  • the secondary winding 4 is bifilar, that is, it consists of two wires wound together in parallel such that the adjacent turns carry current in opposite directions.
  • the secondary winding 4 is connected to the supply of the magnetron heater element 7.
  • the proximity of the two wires produces only a surface effect within the core 2 and magnetic fields generated by the heater current passing along the secondary winding 4 tend to cancel each other out.
  • the magnetron cathode is connected to one of the heater element terminals 8, the other terminal being shown at 9.
  • the B-H curve of the core 2, showing the flux density B as a function of magnetic field strength H is illustrated in Figure 2.
  • the smaller curve, YY1, is the hysterisis loop at low magnetising force and the other loop, ZZ1, is the largest, at which saturation occurs if H2 is exceeded.
  • the curves OXY and OXZ show the curve taken on the first half of the cycle for each loop when the core material is unmagnetised.
  • the part of the hysteris loop at which operation occurs may be by applying biasing to the core 2.
  • the curves WW1 and VV1 are selected by using positive and negative biasing respectively.
  • the remanence R After transmission of the current pulse, and thus removal of the magnetic field, the remanence R remains, decaying in a time depending on the core material, the conditions existing in the core and other external conditions. It is desirable to reset the transformer core between pulses to permit a larger range of the B-H curve to be used, thus maximising the power which can be handled for a given core volume. By producing a relatively large change in B as it decreases, the capability of the core to pass longer pulse widths is enhanced.
  • an additional auxiliary winding 10 is required which is connected to a power supply 11. After a pulse has been transmitted through the primary winding 3, producing magnetisation, a pulse is transmitted through the auxiliary winding 10. This causes a magnetic field to be applied which opposes the effects produced by the pulse through the primary winding 3, resetting the transformer core.
  • the present invention seeks to provide an improved circuit arrangement which includes a transformer core.
  • a circuit arrangement comprising a transformer having a substantially toroidal core and a winding about the core which comprises two wires, one being wound in the opposite sense to the other and at least some of the turns of one wire being wound on a different part of the core to those of the other.
  • the core is typically, but not necessarily of circular cross-section.
  • the use of such a winding enhances the operation of the transformer as it enables a greater change in the B field to be achieved. It is believed that this is because each of the wires produces a magnetic field within the core material, rather than the surface effect produced by the conventional bifilar winding, as at least some of the turns of one wire are spaced apart from those of the other.
  • the fields produced are equal and opposite and thus completely cancel one another.
  • the dipole elements of the core material are acted on by the fields which, although their resultant force is zero, cause the mobility of the dipole elements to be increased as they are in a state of dynamic equilibrium. Due to microscopic variations in dipole strength, size and orientation, changes in the applied field produce a faster response. This enables the core to pass longer pulse widths than is possible using a conventional arrangement.
  • the winding may be arranged such that only part of each of the wires is spaced from the other, but preferably each wire is wound on a different part, so there is no overlap between them.
  • the winding may be separate from others on the core but in a particularly advantageous embodiment, the winding is a secondary winding across which a load is connected.
  • a circuit arrangement comprising a transformer having a secondary winding across which a load is connected and means arranged to pass a current through the secondary winding to reset the transformer core after transmission of current through its primary winding.
  • resetting it is meant that the flux density is reduced from what it would otherwise be, and not necessarily only that negative saturation or remanence is achieved.
  • the additional power supply, auxiliary winding and other circuit elements needed in a conventional arrangement are not required.
  • the invention is particularly applicable to arrangements in which the load is a magnetron, the current used to reset the core also being the heater current for the magnetron. This may be achieved by employing a secondary winding which comprises two windings which are arranged adjacent one another and wound in opposite senses.
  • a circuit arrangement in accordance with the invention includes a transformer 12 having a transformer core 13 about which are wound primary and secondary windings 14 and 15.
  • the primary winding 14 is connected to a d.c. charging circuit 16 similar to that shown in the circuit arrangement of Figure 1.
  • the secondary winding 17 is connected to a load, which in this embodiment is a magnetron.
  • the secondary winding comprises two wires 18 and 19 which are arranged adjacent one another and wound in opposite senses.
  • the secondary winding 17 includes four terminals 20, 21, 22 and 23.
  • the magnetron heater element is connected across two of the terminals 21 and 22 which are arranged between the two parts 18 and 19 of the secondary winding 17.
  • the terminal 21 is also connected to the magnetron cathode.
  • the terminal 20 is the input terminal of the heater supply to which the heater current is applied and the terminal 23 is connected to earth.

Landscapes

  • Engineering & Computer Science (AREA)
  • Power Engineering (AREA)
  • Microwave Tubes (AREA)
  • Control Of High-Frequency Heating Circuits (AREA)
  • Coils Of Transformers For General Uses (AREA)
EP19890305127 1988-05-21 1989-05-10 Disposition de circuit Withdrawn EP0343886A3 (fr)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
GB888812090A GB8812090D0 (en) 1988-05-21 1988-05-21 Circuit arrangements
GB8812090 1988-05-21

Publications (2)

Publication Number Publication Date
EP0343886A2 true EP0343886A2 (fr) 1989-11-29
EP0343886A3 EP0343886A3 (fr) 1990-10-31

Family

ID=10637332

Family Applications (1)

Application Number Title Priority Date Filing Date
EP19890305127 Withdrawn EP0343886A3 (fr) 1988-05-21 1989-05-10 Disposition de circuit

Country Status (3)

Country Link
EP (1) EP0343886A3 (fr)
JP (1) JPH0250408A (fr)
GB (2) GB8812090D0 (fr)

Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB1238341A (fr) * 1968-02-13 1971-07-07
SU636692A1 (ru) * 1975-06-10 1978-12-05 Предприятие П/Я В-8751 Импульсный высокочастотный трансформатор
DE2828721A1 (de) * 1978-06-30 1980-01-10 Ceag Licht & Strom Ausgangsuebertrager fuer wechselrichter
JPS56115510A (en) * 1980-02-19 1981-09-10 Nippon Gakki Seizo Kk Electric power source device
DE3716415A1 (de) * 1986-09-16 1988-03-24 Siemens Ag Gleichrichterschaltung mit einer zur glaettung der ausgangsseitigen pulsierenden laststroeme mit ihrer lastwicklung an den laststromkreis angeschlossenen speicherdrossel

Family Cites Families (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR424425A (fr) * 1909-12-30 1911-05-13 Deutsche Maschf Ag Appareil servant à la fois à saisir les lingots ou lingotières et à extraire les lingots
GB715610A (en) * 1950-09-20 1954-09-15 Gen Electric Co Ltd Improvements in or relating to variable inductive elements having saturable cores
US3030570A (en) * 1958-08-22 1962-04-17 Westinghouse Electric Corp Magnetic amplifier circuit
US3162326A (en) * 1962-11-27 1964-12-22 Unexcelled Chemical Corp Apparatus for processing electrical signals
US3353132A (en) * 1965-05-27 1967-11-14 Gen Electric Leakage flux suppressor windings for transformers
US3414797A (en) * 1966-05-20 1968-12-03 Gen Electric Power converter employing integrated magnetics
US4498128A (en) * 1983-07-07 1985-02-05 At&T Bell Laboratories Current limit circuit in single-ended forward converter utilizing core reset to initiate power switch conduction

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB1238341A (fr) * 1968-02-13 1971-07-07
SU636692A1 (ru) * 1975-06-10 1978-12-05 Предприятие П/Я В-8751 Импульсный высокочастотный трансформатор
DE2828721A1 (de) * 1978-06-30 1980-01-10 Ceag Licht & Strom Ausgangsuebertrager fuer wechselrichter
JPS56115510A (en) * 1980-02-19 1981-09-10 Nippon Gakki Seizo Kk Electric power source device
DE3716415A1 (de) * 1986-09-16 1988-03-24 Siemens Ag Gleichrichterschaltung mit einer zur glaettung der ausgangsseitigen pulsierenden laststroeme mit ihrer lastwicklung an den laststromkreis angeschlossenen speicherdrossel

Non-Patent Citations (5)

* Cited by examiner, † Cited by third party
Title
27th ELECTRONIC COMPONENTS CONFERENCE,ARLINGTON MAY 16-18 1977 pages 115 - 121; Spencer G. Johnston: "DESIGN AND OPERATION OF A FLUX-GATE COMPASS USING A FLOATING CORE" *
IEEE,electronic ind.ass.,Proc.of the electr.compon.conf.,Washingt.May 1966 1966, New York pages 112 - 117; K.Aaland: "SATURATING PULSE TRANSFORMER WITH OPTIMIZED LOAD FOR A SOLENOID LOAD" *
IRE TRANSACTIONS ON COMPONENT PARTS. vol. CP-9, no. 2, June 1962, NEW YORK US pages 58 - 61; REUBEN LEE: "REDUCING SIZE OF RADAR PULSE TRANSFORMERS" *
PATENT ABSTRACTS OF JAPAN vol. 5, no. 192 (E-85)(864) 08 December 1981, & JP-A-56 115510 (NIPPON GAKKI SEIZO K.K.) *
Soviet Inventions Illustrated Derwent week B37,published 24 october 1979,LONDON & SU-A-636692 (GOLINSKII V D) *

Also Published As

Publication number Publication date
GB8911534D0 (en) 1989-07-05
GB2219437A (en) 1989-12-06
GB8812090D0 (en) 1988-06-22
GB2219437B (en) 1992-05-27
EP0343886A3 (fr) 1990-10-31
JPH0250408A (ja) 1990-02-20

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