EP0981266A2 - Dans un four à micro-ondes, le mode de gestion du courant d'initialisation - Google Patents

Dans un four à micro-ondes, le mode de gestion du courant d'initialisation Download PDF

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Publication number
EP0981266A2
EP0981266A2 EP99302885A EP99302885A EP0981266A2 EP 0981266 A2 EP0981266 A2 EP 0981266A2 EP 99302885 A EP99302885 A EP 99302885A EP 99302885 A EP99302885 A EP 99302885A EP 0981266 A2 EP0981266 A2 EP 0981266A2
Authority
EP
European Patent Office
Prior art keywords
winding
motor
microwave oven
relay
current
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.)
Granted
Application number
EP99302885A
Other languages
German (de)
English (en)
Other versions
EP0981266A3 (fr
EP0981266B1 (fr
Inventor
Young Cheol Ko
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.)
Samsung Electronics Co Ltd
Original Assignee
Samsung Electronics Co 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 Samsung Electronics Co Ltd filed Critical Samsung Electronics Co Ltd
Publication of EP0981266A2 publication Critical patent/EP0981266A2/fr
Publication of EP0981266A3 publication Critical patent/EP0981266A3/fr
Application granted granted Critical
Publication of EP0981266B1 publication Critical patent/EP0981266B1/fr
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

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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
    • H05B6/64—Heating using microwaves
    • H05B6/66—Circuits
    • H05B6/68—Circuits for monitoring or control
    • 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
    • H05B6/64—Heating using microwaves
    • H05B6/66—Circuits
    • H05B6/666—Safety circuits

Definitions

  • the present invention relates to a microwave oven comprising a high-voltage transformer for driving a microwave generator, current-limiting means and switching means for introducing the current limiting means in series with the primary winding of the transformer for preventing a current surge therethrough when cooking is started.
  • Microwave ovens are typically provided with surge current protection devices. In the absence of such devices, an initial surge of current at switch-on would produce a damaging output from the high-voltage transformer of the oven's high-voltage power supply.
  • One form of surge protection device routes current to the high-voltage transformer through a current-limiting resistor for a short period after switch-on.
  • a microwave oven according to the present invention is characterised in that the current-limiting means comprises a winding of a motor. Consequently, useful work is done by the current limiting device rather than it merely producing unwanted heat. Also, there is a reduction in the number of components because the motor winding fulfills two functions.
  • the motor drives a turntable in the cooking chamber of the oven.
  • the switching means comprises switches and a control means for controlling the operation of the switches.
  • the switches include a open/close relay between the primary winding of the high-voltage transformer and a power input terminal and a change-over relay having a first, common terminal coupled to said winding, a second terminal coupled to the one side of said open/close relay and a third terminal coupled to a reduced-voltage current source, and the control means is operable to control the relays such that, during an initial period of current supply to the primary winding of the high-voltage transformer, the open/close relay is open and the first and second terminals of the change-over relay are connected and thereafter the open/close relay is closed and the first and third terminals of the change-over relay are connected.
  • the reduced voltage current source is a tap on a winding of a further motor.
  • the reduced voltage is a voltage less than the mains voltage required for operation of the oven.
  • the further motor is a ventilation fan driving motor.
  • a method of operating a microwave oven comprising making a circuit through the primary winding of the high-voltage transformer and the winding of the motor to initiate current flow through the primary winding of the high-voltage transformer and thereafter introducing a short bypassing the winding of the motor.
  • a method according to the present invention includes subsequently connecting the winding of the motor to a current source, other than the primary winding of the high-voltage transformer, for running the motor.
  • the current source is preferably at a voltage less than the mains voltage required for operation of the oven and may be provided by a tap on a winding of another motor.
  • the circuit of a microwave oven comprises a controller 1, a magnetron power supply 2, including a high-voltage transformer 3, and a power routing circuit 4.
  • a low-voltage transformer 5 is connected between the live and neutral terminals of a mains plug 6.
  • the controller 1 is powered from the output of the low-voltage transformer 5.
  • the live terminal 6a of the mains plug 6 is also connected to one terminal of a door switch 7 which opens and closes with the door of the oven's cooking chamber.
  • the other terminal of the door switch 7 is connected to one end of the primary winding of the high-voltage transformer 3.
  • the other end of the primary winding of the high-voltage transformer 3 is coupled to one terminal of a first relay 9 which is opened and closed by the controller 1.
  • the other terminal of the first relay 9 is coupled to the neutral terminal 6b of the mains plug 6.
  • a cooking chamber lamp 10 is connected between one terminal of a second relay 11, which is operated by the controller 1, and the first terminal of the door switch 7.
  • the other terminal of the second relay 11 is connected to the second terminal of the first relay 9.
  • the winding of a turntable motor 12, for driving a turntable in the oven's cooking chamber, is connected between the first terminal of the second relay 11 and a first terminal of a third relay 13 which is also controlled by the controller 1.
  • the third relay 13 is a change-over relay and the first terminal is its common terminal.
  • the second terminal of the third relay 13 is connected to the first terminal of the first relay 9.
  • the winding of a ventilation fan motor 14 is connected between the second terminal of the door switch 7 and the first terminal of the second relay 11.
  • the winding of the ventilation fan motor 14 has a tap which is connected to the third terminal of the third relay 13.
  • step s1 When the user presses a start button, the controller 1 closes the second relay 11 (step s1). This causes the lamp 10 to light up and the turntable and fan motors 12, 14 to start. At this point, the winding of turntable motor 12 is powered from the tap on the winding of the fan motor 14 and no circuit exists between the live and neutral terminals 6a, 6b of the mains plug 6 through the primary winding of the high-voltage transformer 3.
  • the controller 1 After closing the second relay 11, the controller 1 enters a loop (step s2) to determine when 50ms has elapsed. When 50ms has elapsed, the controller 1 switches the third relay 13 (step s3) so that its moving contact connects its first and third terminals. This places the winding of the turntable motor 12 between the primary winding of the high-voltage transformer 3 and the neutral terminal 6b of the mains plug 6 thereby creating a circuit between the live and neutral terminals 6a, 6b of the mains plug 6 through the high-voltage transformer 3. Current now begins to flow through the primary winding of the high-voltage transformer 3. However, it is limited to a safe level by the winding of the turntable motor 12.
  • the controller 1 After switching the third relay 13, the controller 1 enters a loop (step s4) to determine when 50ms has elapsed. When 50ms has elapsed, the controller 1 closes the first relay 9 (step s5) so that the current through the primary winding of the high-voltage transformer 3 is no longer limited by the winding of the turntable motor 12.
  • the controller 1 After switching the first relay 9, the controller 1 enters a loop (step s6) to determine when 50ms has elapsed. When 50ms has elapsed, the controller 1 switches back the third relay 13 (step s7).
  • the delay in switching back the third relay 13 is to ensure that the first relay 9 is closed before the third relay 13 is switched back thereby avoiding momentary isolation of primary winding of the high-voltage transformer 3 from the neutral terminal of the mains plug 6 and the voltage spikes across the high-voltage transformer's secondaries that would result.
  • the controller 1 When the cooking time has elapsed, the controller 1 returns the relays 9, 11, 13 to their original conditions.

Landscapes

  • Physics & Mathematics (AREA)
  • Electromagnetism (AREA)
  • Control Of High-Frequency Heating Circuits (AREA)
EP99302885A 1998-08-20 1999-04-14 Dans un four à micro-ondes, le mode de gestion du courant d'initialisation Expired - Lifetime EP0981266B1 (fr)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
KR1019980033739A KR100271360B1 (ko) 1998-08-20 1998-08-20 전자렌지의 전원제어장치 및 전원제어방법
KR9833739 1998-08-20

Publications (3)

Publication Number Publication Date
EP0981266A2 true EP0981266A2 (fr) 2000-02-23
EP0981266A3 EP0981266A3 (fr) 2000-05-31
EP0981266B1 EP0981266B1 (fr) 2003-07-09

Family

ID=19547702

Family Applications (1)

Application Number Title Priority Date Filing Date
EP99302885A Expired - Lifetime EP0981266B1 (fr) 1998-08-20 1999-04-14 Dans un four à micro-ondes, le mode de gestion du courant d'initialisation

Country Status (3)

Country Link
EP (1) EP0981266B1 (fr)
KR (1) KR100271360B1 (fr)
DE (1) DE69909384T2 (fr)

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN111092545A (zh) * 2019-12-24 2020-05-01 广东美的白色家电技术创新中心有限公司 一种冲击电流抑制装置
CN111830879A (zh) * 2020-07-28 2020-10-27 广东美的厨房电器制造有限公司 控制方法、微波烹饪电器和计算机可读存储介质

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP5138164B2 (ja) * 2005-11-25 2013-02-06 パナソニック株式会社 高周波誘電加熱用電力制御装置およびその制御方法

Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4375587A (en) * 1980-08-13 1983-03-01 The Tappan Company Microwave oven energization circuit and components therefor
GB2141568A (en) * 1983-06-10 1984-12-19 Toshiba Kk Control circuit for a microwave oven
FR2763202A1 (fr) * 1997-05-12 1998-11-13 Samsung Electronics Co Ltd Circuit de prevention de courant de demarrage d'un four micro-ondes

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4375587A (en) * 1980-08-13 1983-03-01 The Tappan Company Microwave oven energization circuit and components therefor
GB2141568A (en) * 1983-06-10 1984-12-19 Toshiba Kk Control circuit for a microwave oven
FR2763202A1 (fr) * 1997-05-12 1998-11-13 Samsung Electronics Co Ltd Circuit de prevention de courant de demarrage d'un four micro-ondes

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN111092545A (zh) * 2019-12-24 2020-05-01 广东美的白色家电技术创新中心有限公司 一种冲击电流抑制装置
CN111092545B (zh) * 2019-12-24 2020-11-17 广东美的白色家电技术创新中心有限公司 一种冲击电流抑制装置
CN111830879A (zh) * 2020-07-28 2020-10-27 广东美的厨房电器制造有限公司 控制方法、微波烹饪电器和计算机可读存储介质

Also Published As

Publication number Publication date
EP0981266A3 (fr) 2000-05-31
DE69909384D1 (de) 2003-08-14
DE69909384T2 (de) 2004-06-09
KR20000014347A (ko) 2000-03-06
EP0981266B1 (fr) 2003-07-09
KR100271360B1 (ko) 2000-11-01

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