WO2003017456A1 - Power supply for induction heating or melting - Google Patents
Power supply for induction heating or melting Download PDFInfo
- Publication number
- WO2003017456A1 WO2003017456A1 PCT/US2002/025414 US0225414W WO03017456A1 WO 2003017456 A1 WO2003017456 A1 WO 2003017456A1 US 0225414 W US0225414 W US 0225414W WO 03017456 A1 WO03017456 A1 WO 03017456A1
- Authority
- WO
- WIPO (PCT)
- Prior art keywords
- output
- inverter
- load coil
- inductive load
- power supply
- Prior art date
Links
Classifications
-
- H—ELECTRICITY
- H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
- H05B—ELECTRIC HEATING; ELECTRIC LIGHT SOURCES NOT OTHERWISE PROVIDED FOR; CIRCUIT ARRANGEMENTS FOR ELECTRIC LIGHT SOURCES, IN GENERAL
- H05B6/00—Heating by electric, magnetic or electromagnetic fields
- H05B6/02—Induction heating
- H05B6/06—Control, e.g. of temperature, of power
- H05B6/067—Control, e.g. of temperature, of power for melting furnaces
-
- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02M—APPARATUS FOR CONVERSION BETWEEN AC AND AC, BETWEEN AC AND DC, OR BETWEEN DC AND DC, AND FOR USE WITH MAINS OR SIMILAR POWER SUPPLY SYSTEMS; CONVERSION OF DC OR AC INPUT POWER INTO SURGE OUTPUT POWER; CONTROL OR REGULATION THEREOF
- H02M5/00—Conversion of ac power input into ac power output, e.g. for change of voltage, for change of frequency, for change of number of phases
- H02M5/40—Conversion of ac power input into ac power output, e.g. for change of voltage, for change of frequency, for change of number of phases with intermediate conversion into dc
- H02M5/42—Conversion of ac power input into ac power output, e.g. for change of voltage, for change of frequency, for change of number of phases with intermediate conversion into dc by static converters
- H02M5/44—Conversion of ac power input into ac power output, e.g. for change of voltage, for change of frequency, for change of number of phases with intermediate conversion into dc by static converters using discharge tubes or semiconductor devices to convert the intermediate dc into ac
- H02M5/453—Conversion of ac power input into ac power output, e.g. for change of voltage, for change of frequency, for change of number of phases with intermediate conversion into dc by static converters using discharge tubes or semiconductor devices to convert the intermediate dc into ac using devices of a triode or transistor type requiring continuous application of a control signal
- H02M5/458—Conversion of ac power input into ac power output, e.g. for change of voltage, for change of frequency, for change of number of phases with intermediate conversion into dc by static converters using discharge tubes or semiconductor devices to convert the intermediate dc into ac using devices of a triode or transistor type requiring continuous application of a control signal using semiconductor devices only
-
- H—ELECTRICITY
- H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
- H05B—ELECTRIC HEATING; ELECTRIC LIGHT SOURCES NOT OTHERWISE PROVIDED FOR; CIRCUIT ARRANGEMENTS FOR ELECTRIC LIGHT SOURCES, IN GENERAL
- H05B6/00—Heating by electric, magnetic or electromagnetic fields
- H05B6/02—Induction heating
- H05B6/04—Sources of current
-
- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02M—APPARATUS FOR CONVERSION BETWEEN AC AND AC, BETWEEN AC AND DC, OR BETWEEN DC AND DC, AND FOR USE WITH MAINS OR SIMILAR POWER SUPPLY SYSTEMS; CONVERSION OF DC OR AC INPUT POWER INTO SURGE OUTPUT POWER; CONTROL OR REGULATION THEREOF
- H02M7/00—Conversion of ac power input into dc power output; Conversion of dc power input into ac power output
- H02M7/42—Conversion of dc power input into ac power output without possibility of reversal
- H02M7/44—Conversion of dc power input into ac power output without possibility of reversal by static converters
- H02M7/48—Conversion of dc power input into ac power output without possibility of reversal by static converters using discharge tubes with control electrode or semiconductor devices with control electrode
- H02M7/4815—Resonant converters
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02B—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO BUILDINGS, e.g. HOUSING, HOUSE APPLIANCES OR RELATED END-USER APPLICATIONS
- Y02B70/00—Technologies for an efficient end-user side electric power management and consumption
- Y02B70/10—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
Definitions
- the present invention relates to an ac power supply for use in induction heating or melting applications wherein the induction power circuit is resonantly tuned.
- FIG. 1 illustrates a conventional power supply 110 that is used in induction heating or melting applications.
- the power supply consists of an ac-to-dc rectifier and filter section 112, a dc-to-ac inverter section 120 and a tuning capacitor section 130.
- a three-phase diode bridge rectifier 114 converts three-phase (A, B, C) ac utility line power into dc power.
- Current limiting reactor Lios smoothes out the ripple in the output dc current of the rectifier, and capacitor Cms filters the ac component from the output dc voltage of the rectifier.
- the filtered dc output of the rectifier is inverted to ac by a full-bridge inverter consisting of solid state switches Sioi, S102, S ⁇ 03 and S ⁇ 0 and associated antiparallel diodes Dmi, D 102 , D 103 and D ⁇ o , respectively. Alternating turn-on/turn-off cycles of switch pairs S101/S103 and S 1 o 2 S 1 o produce a synthesized ac inverter output at terminals 3 and 4.
- Induction load coil L 10 ⁇ represents the power coil used in the induction heating or melting application.
- load coil L1 0 1 is wound around the exterior of a crucible in which metal charge has been placed.
- a metal workpiece such as a strip or wire, may travel through a helical winding of load coil L101 or otherwise be brought near to the coil to inductively heat the workpiece.
- Current supplied by the power supply and flowing through load coil Lioi creates a magnetic field that either directly heats the metal charge or workpiece by magnetic induction, or heats the workpiece by heat conduction from a susceptor that is heated by magnetic induction.
- Load coil Lioi whether it be a single coil or an assembly of interconnected coil sections, has a very low operating power factor. Because of this, a tuning capacitor (or bank of capacitors), such as capacitor Cioi must be provided in the load coil circuit to improve the overall power factor of the load coil circuit. These tuning capacitors are a significant cost and volume component of the power supply. Therefore, there exists the need for a power supply for inductive heating or melting applications that utilizes smaller and less costly tuning capacitors.
- An objective of the present invention is to provide a power supply for inductive heating or melting applications that utilizes a capacitor connected between the output of the rectifier and the input of the inverter to form a resonantly tuned circuit with the induction load coil used in the application.
- the present invention is apparatus for, and a method of, providing a power supply with rectifier and inverter sections for use with an induction load coil wherein a tuning capacitor is provided across the output of the rectifier and the input of the inverter to form a resonant circuit with the induction load coil.
- the induction load coil may comprise an active load coil connected to the output of the inverter, and a passive load coil connected in parallel with a capacitor to form a tank circuit.
- FIG. 1 is a schematic diagram of a prior art power supply with a full-bridge inverter that is used in induction heating and melting applications.
- FIG. 2 is a schematic diagram of one example of the power supply of the present invention for use in induction heating or melting applications.
- FIG. 3 is a waveform diagram illustrating the inverter's output voltage and current for one example of the power supply of the present invention.
- FIG. 4 is a waveform diagram illustrating the voltage across a tuning capacitor and the current through a line filtering reactor used in one example of the power supply of the present invention.
- FIG. 5 is a waveform diagram illustrating the voltage across, and current through, a switching device used in the inverter in one example of the power supply of the present invention.
- FIG. 6 is a schematic diagram of another example of the power supply of the present invention for use in induction heating or melting applications.
- FIG. 7 is a vector diagram illustrating the advantages of an induction heating or melting system with the power supply of the present invention used with the load coil system illustrated in FIG. 6.
- FIG. 2 an illustration of one example of power supply 10 of the present invention for use in induction heating or melting applications.
- Ac-to-dc rectifier and filter section 12 includes an ac-to-dc rectifier.
- a multi-phase rectifier in this non- limiting example of the invention, a three- phase diode bridge rectifier 14 is used to convert three-phase (A, B, C) ac utility line power into dc power.
- Optional current limiting reactor L 8 smoothes out the ripple from the output dc current of the rectifier.
- Section 16 of the power supply diagrammatically illustrates coil tuning capacitor Ci, which can be a single capacitor or a bank of interconnected capacitors that form a capacitive element.
- the dc output of the rectifier is supplied to input terminals 1 and 2 of a full- bridge inverter in inverter section 20.
- the inverter consists of solid state switches Si, S 2 , S 3 and S and associated antiparallel diodes Di, D 2 , D 3 and D 4 , respectively. Alternating turn- on/turn-off cycles of switch pairs S1/S3 and S 2 /S 4 produce a synthesized ac inverter output at terminals 3 and 4.
- a preferred, but not limiting, choice of component for the solid state switch is an isolated gate bipolar transistor (IGBT), which exhibits the desirable characteristics of power bipolar transistors and power MOS-FETs at high operating voltages and currents.
- IGBT isolated gate bipolar transistor
- the inverter employs a phase-shifting scheme (pulse width control) relative to the turn-on/turn-off cycles of the two switch pairs whereby variable overlapping on- times for the two switch pairs is used to vary the effective RMS output voltage of the inverter.
- phase-shifting scheme pulse width control
- Induction load coil L 9 represents the power coil used in the induction heating or melting apparatus.
- the capacitance of capacitor Ci is selected to form a resonant circuit with the impedance of load coil L 9 at the operating frequency of the inverter, which is the switching rate of the switch pairs used in the inverter. Consequently, a tuning capacitor is not required at the output of the inverter. Selection of available circuit components may not allow operation exactly at resonance, but as close to resonance as is achievable with available components.
- the ac current flowing through induction load coil L 9 from the output of the inverter magnetically couples with an electrically conductive material, which may be, for example, a conductive metal or a susceptor.
- FIG. 3 through FIG. 5 illustrate the performance characteristics for power supply 10 of the present invention as shown in FIG. 2 with input utility line power (A, B, C) of 480 volts line- to-line, 60 Hertz, and inverter 20 operating at an output frequency of 60 Hz.
- input utility line power A, B, C
- inverter 20 operating at an output frequency of 60 Hz.
- L 8 is selected as 5,000 ⁇ H (for an impedance of 3.77 ohms at the rectifier ripple output frequency of 120 Hz)
- Ci is selected as 5,000 ⁇ F (for an impedance of 0.27 ohms at the rectifier ripple output frequency of 120 Hz)
- L 9 is selected as 1,000 ⁇ H (for an impedance of 0.38 ohms at the inverter output frequency of 60 Hz).
- FIG. 4 graphically illustrates that the voltage across capacitor C ⁇ , namely Vci, is driven to its limiting lower value of zero volts as a result of capacitor C ⁇ being in resonance with coil L 9 at the ripple frequency of 120 Hz.
- Vci is the applied voltage to the input of inverter 20 (at terminals 1 and 2).
- FIG. 4 also illustrates the ripple current, I LS , through reactor L 8 .
- the impedance of reactor L 8 is generally selected to be much greater than the impedance of Ci to block feedback of harmonics from the inverter circuit to the rectifier's power source.
- FIG. 5 graphically illustrates the voltage, V s , across one of the solid state switches in inverter 20, and the current, Is, through one of the switches at maximum power output when there is zero overlap angle between V s and I s . Switching device turn-off at zero volts for V s when dc ripple has reached zero (e.g., at 240.0 milliseconds (ms) in FIG. 4 and FIG. 5), will minimize switching loses.
- any spikes due to stray circuit inductance will be significantly less than in a conventional inverter having low ac ripple current in the dc link voltage.
- FIG. 6 illustrates a second example of the present invention.
- the load coil consists of an active coil L] and at least one passive coil L 2 .
- Coils Lj and L 2 may be wound in one of various configurations, such as sequentially or overlapped, to accomplish mutual magnetic coupling of the coils as further described below.
- Coil Li is connected to the output of inverter 20.
- Coil L 2 is connected in parallel with resonant tuning capacitor C 2 to form a parallel tank resonant circuit.
- Coil L 2 is not physically connected to coil Li.
- the parallel tank resonant circuit is energized by magnetically coupling coil L 2 with the magnetic field generated in coil Li when current supplied from the output of inverter 20 flows through coil Li.
- vector OV represents current L in active coil Li as illustrated FIG. 6.
- Vector OA represents the resistive component of the active coil's voltage, IjRi (Ri not shown in the figures).
- Vector AB represents the inductive component of the active coil's voltage, ⁇ LiL (where ⁇ equals the product of 2 ⁇ and f, the operating frequency of the power supply).
- Vector BC represents the voltage, ⁇ MI 2 , induced by the passive coil L 2 onto active coil Li.
- Vci across capacitor Ci and the switching function of the two switch pairs S1/S 3 and S 2 /S produce the effect of a pseudo capacitor CV connected in series with Li that would result in a sinusoidal voltage at terminals 5 and 6 in FIG. 6.
- Vector CD represents the voltage, I ⁇ / ⁇ C ⁇ ', that would appear across this pseudo series capacitor Ci'.
- Vector OD represents the output voltage, Vj consumer v , of the inverter (terminals 3 and 4 in FIG. 6).
- vector OW represents current I 2 in passive coil L 2 that is induced by the magnetic field produced by current l ⁇ .
- Vector OF represents the resistive component of the passive coil's voltage, I2R 2 (R 2 not shown in the figures).
- Vector FE represents the inductive component of the active coil's voltage, ⁇ L 2 l 2 .
- Vector EG represents the voltage, ⁇ MIi, induced by the active coil Li onto passive coil L 2 .
- Vector GO represents the voltage, I2/C0C 2 , on capacitor C 2 , which is connected across passive coil L 2 .
- the active coil circuit is driven by the voltage source, V inv , which is the output of inverter 20, while the passive coil loop is not connected to an active energy source. Since the active and passive coils are mutually coupled, vector BC is added to vector OB, V LOAD , which represents the voltage across an active induction load coil in the absence of a passive capacitive load coil circuit, to result in vector OC, V LO ⁇ D , which is the voltage across an active load coil with a passive capacitive load coil circuit of the present invention.
- the resultant load voltage, V LOAD has a smaller lagging power factor angle, ⁇ (counterclockwise angle between the x-axis and vector OC), than the conventional load coil as represented by vector OB. As illustrated in FIG. 7, there is a power factor angle improvement of ⁇ .
- the uncompensated resistive component, R 2 in the passive coil circuit is reflected into the active coil circuit by the mutual inductance between the two circuits, and the effective active coil circuit's resistance is increased, thus improving the power factor angle, or efficiency of the coil system.
- the power factor angle, ⁇ , for the output of the inverter improves by ⁇ as illustrated by the angle between vector OJ, V j nv (resultant vector of resistive component vector O A and capacitive component vector AJ in the absence of a passive load coil circuit) and vector OD, V inv (resultant vector of resistive component vector OH and capacitive component vector HD with a passive load coil circuit of the present invention).
- multiple active and/or passive coil circuits may be used to achieve a desired multiple coil arrangement for a particular application.
- the examples of the invention include reference to specific electrical components.
- One skilled in the art may practice the invention by substituting components that are not necessarily of the same type but will create the desired conditions or accomplish the desired results of the invention.
- single components may be substituted for multiple components or vice versa.
- Further one skilled in the art may practice the invention by rearranging components to create the desired conditions or accomplish the desired results of the invention. While the examples illustrate operation of the invention in full-bridge voltage-fed power supplies, the invention is applicable to other power supply topologies with appropriate modifications as understood by one who is skilled in the art.
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- Physics & Mathematics (AREA)
- Electromagnetism (AREA)
- Engineering & Computer Science (AREA)
- Power Engineering (AREA)
- General Induction Heating (AREA)
- Inverter Devices (AREA)
Abstract
Description
Claims
Priority Applications (8)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
BR0211940-4A BR0211940A (en) | 2001-08-14 | 2002-08-12 | Power supply and method for inductively heating or fusing an electrically conductive material |
AU2002313733A AU2002313733B2 (en) | 2001-08-14 | 2002-08-12 | Induction heating or melting power supply utilizing a tuning capacitor |
ES02753445.2T ES2565452T3 (en) | 2001-08-14 | 2002-08-12 | Power supply source for heating or induction melting |
KR1020047002246A KR101021560B1 (en) | 2001-08-14 | 2002-08-12 | Power supply for induction heating or melting |
MXPA04001390A MXPA04001390A (en) | 2001-08-14 | 2002-08-12 | Power supply for induction heating or melting. |
JP2003522249A JP4092293B2 (en) | 2001-08-14 | 2002-08-12 | Power supply for induction heating or melting |
EP02753445.2A EP1423907B1 (en) | 2001-08-14 | 2002-08-12 | Power supply for induction heating or melting |
CA002456473A CA2456473A1 (en) | 2001-08-14 | 2002-08-12 | Power supply for induction heating or melting |
Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US31215901P | 2001-08-14 | 2001-08-14 | |
US60/312,159 | 2001-08-14 |
Publications (1)
Publication Number | Publication Date |
---|---|
WO2003017456A1 true WO2003017456A1 (en) | 2003-02-27 |
Family
ID=23210137
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
PCT/US2002/025414 WO2003017456A1 (en) | 2001-08-14 | 2002-08-12 | Power supply for induction heating or melting |
Country Status (11)
Country | Link |
---|---|
US (1) | US6696770B2 (en) |
EP (1) | EP1423907B1 (en) |
JP (1) | JP4092293B2 (en) |
KR (1) | KR101021560B1 (en) |
CN (1) | CN100361380C (en) |
AU (1) | AU2002313733B2 (en) |
BR (1) | BR0211940A (en) |
CA (1) | CA2456473A1 (en) |
ES (1) | ES2565452T3 (en) |
MX (1) | MXPA04001390A (en) |
WO (1) | WO2003017456A1 (en) |
Cited By (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
EP1719388A1 (en) * | 2004-02-21 | 2006-11-08 | Inductotherm Corp. | Induction heating or melting power supply utilizing a tuning capacitor |
Families Citing this family (25)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US7279665B2 (en) * | 2003-07-02 | 2007-10-09 | Itherm Technologies, Lp | Method for delivering harmonic inductive power |
US7034263B2 (en) * | 2003-07-02 | 2006-04-25 | Itherm Technologies, Lp | Apparatus and method for inductive heating |
US7022952B2 (en) * | 2003-08-26 | 2006-04-04 | General Electric Company | Dual coil induction heating system |
US7772530B2 (en) * | 2004-10-30 | 2010-08-10 | Inductotherm Corp. | Induction heat treatment of workpieces |
US9370049B2 (en) * | 2004-12-08 | 2016-06-14 | Inductotherm Corp. | Electric induction heating, melting and stirring of materials non-electrically conductive in the solid state |
BRPI0518867B1 (en) * | 2004-12-08 | 2018-05-08 | Inductotherm Corp | apparatus for heating or melting by electric induction of an electrically conductive material, and method of controlling heating or melting by electric induction of an electrically conductive material |
US7582851B2 (en) * | 2005-06-01 | 2009-09-01 | Inductotherm Corp. | Gradient induction heating of a workpiece |
JP2009506743A (en) * | 2005-08-25 | 2009-02-12 | コンサーク コーポレイション | Pulse width modulation power inverter output control |
JP4441691B2 (en) * | 2007-02-06 | 2010-03-31 | 国立大学法人東京工業大学 | AC / DC power converter |
CN101658066B (en) * | 2007-04-07 | 2012-09-05 | 应达公司 | Current fed inverter with pulse regulator for electric induction heating, melting and stirring |
WO2009058820A2 (en) * | 2007-11-03 | 2009-05-07 | Inductotherm Corp. | Electric power system for electric induction heating and melting of materials in a susceptor vessel |
EP2112862B1 (en) * | 2008-04-25 | 2013-04-10 | Electrolux Home Products Corporation N.V. | Method and arrangement for dynamic wave form correction |
JP5397668B2 (en) * | 2008-09-02 | 2014-01-22 | ソニー株式会社 | Storage element and storage device |
US20120037616A1 (en) * | 2008-10-27 | 2012-02-16 | Merstech Inc. | Power inverter |
CN102564125A (en) * | 2011-04-20 | 2012-07-11 | 泰州杰利瑞节能科技发展有限公司 | Ultrasonic-frequency induction heating smelting furnace |
EP2546969A1 (en) * | 2011-07-14 | 2013-01-16 | Siemens Aktiengesellschaft | Method for controlling a frequency converter and frequency converter |
ITTO20120896A1 (en) | 2012-10-15 | 2014-04-16 | Indesit Co Spa | INDUCTION HOB |
US10605464B2 (en) | 2012-10-15 | 2020-03-31 | Whirlpool Corporation | Induction cooktop |
US10076003B2 (en) | 2014-09-05 | 2018-09-11 | Kenyon International, Inc. | Induction cooking appliance |
US9677700B2 (en) | 2014-10-27 | 2017-06-13 | Ajax Tocco Magnethermic Corporation | Pipe heating apparatus and methods for uniform end heating and controlled heating length |
JP2016158344A (en) * | 2015-02-24 | 2016-09-01 | 株式会社日立製作所 | Power conversion device and elevator |
ITUB20152674A1 (en) | 2015-07-30 | 2017-01-30 | Danieli Automation Spa | APPARATUS AND METHOD OF ELECTRIC SUPPLY OF AN ARC ELECTRIC OVEN |
EP3432682A1 (en) | 2017-07-18 | 2019-01-23 | Whirlpool Corporation | Method for operating an induction cooking hob and cooking hob using such method |
US10993292B2 (en) | 2017-10-23 | 2021-04-27 | Whirlpool Corporation | System and method for tuning an induction circuit |
US11140751B2 (en) | 2018-04-23 | 2021-10-05 | Whirlpool Corporation | System and method for controlling quasi-resonant induction heating devices |
Citations (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US6141227A (en) * | 1999-06-03 | 2000-10-31 | Cheltenham Induction Heating Limited Of Phoenix Works | Power supply with reduced second harmonic |
Family Cites Families (8)
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US4115676A (en) * | 1976-02-10 | 1978-09-19 | Tokyo Shibaura Electric Co., Ltd. | Induction heating apparatus |
US4426564A (en) * | 1979-12-26 | 1984-01-17 | General Electric Company | Parallel resonant induction cooking surface unit |
US4638138A (en) * | 1984-07-23 | 1987-01-20 | Westinghouse Electric Corp. | High frequency inverter circuit for melting and induction heating |
FR2680922B1 (en) * | 1991-08-26 | 1995-02-17 | Electricite De France | METHOD FOR REGULATING A QUASI-RESONANCE VOLTAGE INVERTER. |
DE19527827C2 (en) | 1995-07-29 | 1998-02-12 | Kuka Schweissanlagen & Roboter | Method and device for generating electrical heat |
US5968398A (en) * | 1997-05-16 | 1999-10-19 | The Lepel Corporation | Apparatus and method for non-contact detection and inductive heating of heat retentive food server warming plates |
DE19731690C2 (en) * | 1997-07-23 | 1999-10-28 | Siemens Ag | Power amplifier and magnetic resonance imaging |
KR100872002B1 (en) * | 2001-02-16 | 2008-12-05 | 인덕터썸코포레이션 | Simultaneous induction heating and stirring of a molten metal |
-
2002
- 2002-08-12 WO PCT/US2002/025414 patent/WO2003017456A1/en active Application Filing
- 2002-08-12 AU AU2002313733A patent/AU2002313733B2/en not_active Expired
- 2002-08-12 KR KR1020047002246A patent/KR101021560B1/en active IP Right Grant
- 2002-08-12 US US10/217,081 patent/US6696770B2/en not_active Expired - Lifetime
- 2002-08-12 EP EP02753445.2A patent/EP1423907B1/en not_active Expired - Lifetime
- 2002-08-12 MX MXPA04001390A patent/MXPA04001390A/en active IP Right Grant
- 2002-08-12 ES ES02753445.2T patent/ES2565452T3/en not_active Expired - Lifetime
- 2002-08-12 BR BR0211940-4A patent/BR0211940A/en not_active IP Right Cessation
- 2002-08-12 JP JP2003522249A patent/JP4092293B2/en not_active Expired - Lifetime
- 2002-08-12 CA CA002456473A patent/CA2456473A1/en not_active Abandoned
- 2002-08-12 CN CNB028160398A patent/CN100361380C/en not_active Expired - Lifetime
Patent Citations (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US6141227A (en) * | 1999-06-03 | 2000-10-31 | Cheltenham Induction Heating Limited Of Phoenix Works | Power supply with reduced second harmonic |
Cited By (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
EP1719388A1 (en) * | 2004-02-21 | 2006-11-08 | Inductotherm Corp. | Induction heating or melting power supply utilizing a tuning capacitor |
EP1719388A4 (en) * | 2004-02-21 | 2009-10-21 | Inductotherm Corp | Induction heating or melting power supply utilizing a tuning capacitor |
Also Published As
Publication number | Publication date |
---|---|
ES2565452T3 (en) | 2016-04-04 |
EP1423907A4 (en) | 2008-11-19 |
JP2005500796A (en) | 2005-01-06 |
BR0211940A (en) | 2004-09-21 |
CN100361380C (en) | 2008-01-09 |
CN1543702A (en) | 2004-11-03 |
MXPA04001390A (en) | 2004-05-27 |
AU2002313733B2 (en) | 2006-07-20 |
EP1423907A1 (en) | 2004-06-02 |
CA2456473A1 (en) | 2003-02-27 |
KR20040023752A (en) | 2004-03-18 |
JP4092293B2 (en) | 2008-05-28 |
US6696770B2 (en) | 2004-02-24 |
EP1423907B1 (en) | 2016-02-17 |
US20030035309A1 (en) | 2003-02-20 |
KR101021560B1 (en) | 2011-03-16 |
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