US2513512A - Variable-current transformer - Google Patents

Variable-current transformer Download PDF

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Publication number
US2513512A
US2513512A US794733A US79473347A US2513512A US 2513512 A US2513512 A US 2513512A US 794733 A US794733 A US 794733A US 79473347 A US79473347 A US 79473347A US 2513512 A US2513512 A US 2513512A
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US
United States
Prior art keywords
winding
core
current
transformer
variable
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Expired - Lifetime
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US794733A
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English (en)
Inventor
Olthof Menno
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.)
HANDELSVENNOOTSCHAP TRANSFORMA
Handelsvennootschap Transformatorenfabriek Gebr Firma
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HANDELSVENNOOTSCHAP TRANSFORMA
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Publication date
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Publication of US2513512A publication Critical patent/US2513512A/en
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Expired - Lifetime legal-status Critical Current

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    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01F—MAGNETS; INDUCTANCES; TRANSFORMERS; SELECTION OF MATERIALS FOR THEIR MAGNETIC PROPERTIES
    • H01F38/00—Adaptations of transformers or inductances for specific applications or functions
    • H01F38/08—High-leakage transformers or inductances
    • H01F38/085—Welding transformers
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01F—MAGNETS; INDUCTANCES; TRANSFORMERS; SELECTION OF MATERIALS FOR THEIR MAGNETIC PROPERTIES
    • H01F29/00—Variable transformers or inductances not covered by group H01F21/00
    • H01F29/08—Variable transformers or inductances not covered by group H01F21/00 with core, coil, winding, or shield movable to offset variation of voltage or phase shift, e.g. induction regulators
    • H01F29/10—Variable transformers or inductances not covered by group H01F21/00 with core, coil, winding, or shield movable to offset variation of voltage or phase shift, e.g. induction regulators having movable part of magnetic circuit

Definitions

  • the invention relates to a transformer, particularly a, welding transformer adapted to produce a variable current, having in combination a wide range of regulation, a steep voltage-cur- .rent characteristic and a substantially constant no-load voltage.
  • the voltage-current characteristic is of great importance for variable welding transformers. If thecharacteristic is steep slight variations of the current will occur as the arc voltage varies during the welding process,'so that a uniform weld will be obtained.
  • FIG. l The principle of the transformer according to the invention is shown in Figure l.
  • I is the primary winding, 2 the secondary. winding, and the magnetic shunt.
  • the current produced in the closed position of the magnetic shunt shown in Figure 1 will be a minimum; the current will be a maximum if the magnetic shunt is coupled as little as possible with the fixed yoke of the transformer.
  • the voltage-current characteristic will be steep in view of the minor coupling between the primary winding l and the secondary winding 2, the range of regulation will be very small. Moreover, if only a narrow or practically no air gap is used in the closed position of the magnetic shunt in order to increase the range of regulation as much as possible, the no-load voltage in this position will be strongly reduced, as part of the magnetising flux will flow through the magnetic shunt, which is undesirable.
  • FIGS 2 and 2a show other forms of known welding transformers.
  • the magnetic shunt 5 is provided with a winding 4 forming a portion of the secondary winding of the transformer.
  • the secondary winding comprises a portion 3 traversed by the flux in the fixed core also carrying the primary winding l, and the portion 4 which is connected in series with the portion 3 and is traversed by the flux in the adjustable shunt core 5.
  • the secondary winding further comprises a portion 2 which is traversed 2 by the flux in a second fixed core and is connected in series with the portions 3 and 4.
  • the transformer may be regulated by rotating the movable'shunt core 5 about the axis 6 indicated in. dotted lines.
  • the winding 4 and the movable core 5 will constitute a choke coil the reactance of which is varied by increasing and decreasing its magnetic resistance.
  • the reactance will be a minimum (and the current will be a maximum) when the air gap between the adjustable core 5 and the fixed yoke is as large as possible, and the reactance will be a maximum (and the current a minimum) in the closed position of the core 5 shown in the figures.
  • the magnetising current occurring in the closed position of the core 5 will cause the reactance to depend on the winding sense of the winding 4 as compared with the winding 3. Said winding sense depends upon the rotation of the core 5 about the axis 6. In the case of an opposing'winding sense the reactance will be a maximumand the current will be a minimum. With this winding sense the no-load voltage in the closed position of the core 5 will be substantially less than in the open position, which is a drawback.
  • the invention provides a, variable welding transformer having a steep voltage-current characteristic combined with both a wide range of regulation and a substantially constant noload voltage.
  • a circuit having a first portion of the secondar winding which is traversed by the flux in a fixed core also carrying the primary winding, a second portion of the secondary winding which is connected in series with the first portion and is traversed by the flux in an adjustable shunt core. and a third portion of the sec ondary winding which is traversed by the flux in a fixed core, this result is produced by connecting said third portion in parallel with the series connection of said first and second portions.
  • the main advantage or the circuit according to the invention is that as a result of this parallel connection the volume of the transformer may be substantially reduced without afiecting the properties required for a good welding transformer.
  • the winding 1 is the primary winding l.
  • the secondary winding comprises the portion 2 connected in parallel with the series connection of I the portions 3 and 4.
  • the portion 2 is a fixed winding coupled with the primary winding I.
  • the winding 3 is also coupled with the primary winding i.
  • the reactance of the winding 6, as contrasted with that of the corresponding winding in Figure 2 or 2a, will depend upon the nu in the fixed yoke and the adjustable core produced by the strong field repelling action which will-occur when the winding portion 2 is being loaded, In the case of equal winding senses said reactance will be much higher than in Figure 2 or 2a, whereas for opposing winding senses the reactance will be even less than in the position of the core 5 of maximum air gap.
  • her of turns will merely influence the reduction of current in the closed position of the core 6 with opposing winding sense of the winding portion 4, and the increase of current in the closed position of the core 5 with assisting sense. 7
  • the no-load voltage will not submit substantial variationsin the diflerent positions oi. the adjustable core 5, as in view of the parallel connection of the winding portions 2 and 3 the winding portion 4 will substantially compensate any voltage diiierence that might tend to dedevelop between the winding portions 2 and 3 as a result of the leakage flux in the core 5.
  • the current may be taken from the winding 2 either directly or by means of a transformer.
  • a variable current transformer comprising a core having a main core section, a fixed shunt section and a movable shunt section, a primary winding on said main core section, and a sec-' .ondary winding comprising three parts mounted respectively on said three core sections, the parts of said secondary winding mounted on said main and movable core sections being connected in series with, each other andin parallel with the part of said secondary winding mounted on said fixed shunt section.
  • variable current transformer in which the winding sense of the two series connected parts of the secondary winding is mutually reversible, so that in combination with the parallel connected part of the secondary winding a wide range of regulation is obtainable.
  • a variable current transformer having a stationary core member comprising two parallel core legs, a movable shunt core member, a primary winding and a first secondary winding portion disposed on oneoi said parallel core legs, a second secondary winding portion connected in series with the first secondary winding portion and disposed on the movable shunt core member, and a third secondary winding portion disposed on the other of said parallel core legs and connected in parallel with the series connection of the first and second secondary winding portions.

Landscapes

  • Engineering & Computer Science (AREA)
  • Power Engineering (AREA)
  • Coils Of Transformers For General Uses (AREA)
  • Arc Welding Control (AREA)
US794733A 1941-12-19 1947-12-30 Variable-current transformer Expired - Lifetime US2513512A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
NL634426X 1941-12-19

Publications (1)

Publication Number Publication Date
US2513512A true US2513512A (en) 1950-07-04

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Application Number Title Priority Date Filing Date
US794733A Expired - Lifetime US2513512A (en) 1941-12-19 1947-12-30 Variable-current transformer

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US (1) US2513512A (xx)
GB (1) GB634426A (xx)
NL (1) NL69203C (xx)

Cited By (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2694177A (en) * 1951-03-16 1954-11-09 Joseph G Sola Transformer having constant and harmonic free output voltage
US2789245A (en) * 1953-09-30 1957-04-16 Strong Electric Corp Arc lamp
US20050243582A1 (en) * 2004-04-30 2005-11-03 Hon Hai Precision Industry Co., Ltd. DC transformer with an output inductance integrated on a magnetic core thereof and a DC/DC converter employing the same
US20080048818A1 (en) * 2006-08-25 2008-02-28 Hong Mao Transformers with improved voltage-step-down ratios and DC-to-DC power converters employing same
US20090167474A1 (en) * 2007-12-27 2009-07-02 Samsung Electro-Mechanics Co., Ltd Transformer improved in leakage inductance
DE102008049432A1 (de) * 2008-09-25 2010-04-01 Siemens Aktiengesellschaft Leistungsschalter und Stromwandler für einen Leistungsschalter
US11120936B2 (en) * 2018-07-18 2021-09-14 Delta Electronics, Inc. Magnetic component module

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3335379A (en) * 1965-07-20 1967-08-08 Carl G Howard Adjustable voltage transformer

Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US1831886A (en) * 1929-11-11 1931-11-17 Julian J Ross Transformer
US2187523A (en) * 1936-05-13 1940-01-16 Union Switch & Signal Co Electrical regulating apparatus
US2364881A (en) * 1942-09-10 1944-12-12 Air Reduction Welding transformer

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US1831886A (en) * 1929-11-11 1931-11-17 Julian J Ross Transformer
US2187523A (en) * 1936-05-13 1940-01-16 Union Switch & Signal Co Electrical regulating apparatus
US2364881A (en) * 1942-09-10 1944-12-12 Air Reduction Welding transformer

Cited By (11)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2694177A (en) * 1951-03-16 1954-11-09 Joseph G Sola Transformer having constant and harmonic free output voltage
US2789245A (en) * 1953-09-30 1957-04-16 Strong Electric Corp Arc lamp
US20050243582A1 (en) * 2004-04-30 2005-11-03 Hon Hai Precision Industry Co., Ltd. DC transformer with an output inductance integrated on a magnetic core thereof and a DC/DC converter employing the same
US7375607B2 (en) * 2004-04-30 2008-05-20 Hon Hai Precision Industry Co., Ltd. DC transformer with an output inductance integrated on a magnetic core thereof and a DC/DC converter employing the same
US20080048818A1 (en) * 2006-08-25 2008-02-28 Hong Mao Transformers with improved voltage-step-down ratios and DC-to-DC power converters employing same
US20090167474A1 (en) * 2007-12-27 2009-07-02 Samsung Electro-Mechanics Co., Ltd Transformer improved in leakage inductance
US20110032062A1 (en) * 2007-12-27 2011-02-10 Samsung Electro-Mechanics Co., Ltd. Transformer improved in leakage inductance
US8299881B2 (en) 2007-12-27 2012-10-30 Samsung Electro-Mechanics Co., Ltd. Transformer improved in leakage inductance
DE102008049432A1 (de) * 2008-09-25 2010-04-01 Siemens Aktiengesellschaft Leistungsschalter und Stromwandler für einen Leistungsschalter
DE102008049432B4 (de) * 2008-09-25 2018-02-08 Siemens Aktiengesellschaft Leistungsschalter und Stromwandler für einen Leistungsschalter
US11120936B2 (en) * 2018-07-18 2021-09-14 Delta Electronics, Inc. Magnetic component module

Also Published As

Publication number Publication date
GB634426A (en) 1950-03-22
NL69203C (xx)

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