CN1463171A - Microwave oven - Google Patents
Microwave oven Download PDFInfo
- Publication number
- CN1463171A CN1463171A CN02126544A CN02126544A CN1463171A CN 1463171 A CN1463171 A CN 1463171A CN 02126544 A CN02126544 A CN 02126544A CN 02126544 A CN02126544 A CN 02126544A CN 1463171 A CN1463171 A CN 1463171A
- Authority
- CN
- China
- Prior art keywords
- relay
- power
- microwave oven
- current
- cooking
- 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.)
- Pending
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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
- H05B6/6414—Aspects relating to the door of the microwave heating apparatus
- H05B6/6417—Door interlocks of the microwave heating apparatus and related circuits
-
- 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
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- Physics & Mathematics (AREA)
- Electromagnetism (AREA)
- Control Of High-Frequency Heating Circuits (AREA)
- Emergency Protection Circuit Devices (AREA)
Abstract
The microwave oven includes an alternating power source, a cooking timer for setting cooking time, a relay for supplying the alternating power to a primary coil of a high voltage transformer (HVT), and a current limiting means (PTC) for attenuating a surge current produced when the alternating power is applied through the relay. The relay includes a relay coil and a relay switch (SWIR) responding to the operation of the cooking timer. The current limiting means is characterized in that its resistance increases in proportion to internal temperature of the current limiting means. Suitably, the current limiting means is a positive temperature coefficient (PTC) thermistor.
Description
Technical field
The present invention relates to a kind of microwave oven, this microwave oven can prevent that surge current from causing the microwave oven faulty operation and causing on fire.
Background technology
Domestic electric appliance will produce transient current when comprising the microwave oven supply power starting, and the surge current more much bigger than common current is loaded into and can causes electrical equipment to be damaged on the electrical equipment.
In conventional microwave oven, adopt current-limiting resistance to prevent that surge current from bringing destruction usually.This technical scheme will 1 describe in conjunction with the accompanying drawings.
Fig. 1 is a kind of circuit diagram of conventional microwave oven, and in this kind microwave oven course of work, cooking time and power grade are manually set by the user.
As shown in Figure 1, first, second power line L1, the L2 that is used to import common AC power links to each other with the two ends of high-tension transformer (HVT) primary coil 7a through noise filter 1.Noise filter 1 is made up of main fuse FUSE1, capacitor C1-C3, inductor L and resistor R 1 etc.Noise filter 1 is suitable with the operation principle of common noise filter, for for simplicity, at this noise filter 1 operation principle is not elaborated.
The first power line L1 is connected in series: magnetron temperature sensor TCO1, its according to magnetron MGT temperature closure or open circuit to prevent magnetron MGT temperature overheating; The first gate controlled switch SW1, its On/Off state according to door of microwave oven come the closed of control circuit or disconnect; The output control switch SW of the power output of controlled microwave stove
VPMonitor switch with the On/Off state that is used to monitor door of microwave oven.
In addition, second source line L2 is connected in series: cooking room temperature sensor TCO2, and its temperature closure or open circuit according to cooking room is overheated to prevent cooking room; Be used for the controlled microwave stove timer switch SW of cooking time
TMBe used to prevent the relay switch SW of surge current
IRWith the second gate controlled switch SW2, it is according to the On/Off state closure or the open circuit of door of microwave oven.
In addition, between the first power line L1 and second source line L2, also be connected with illuminating lamp 2, fan electromotor 3, drive motors 4 and timer motor 5.Wherein, illuminating lamp 2, fan electromotor 3 and timer motor 5 are by the power drives of common voltage (AC220V), and low-voltage (AC21V) power drives of drive motors 4 by drawing from fan electromotor 4 coils one side.
Also has timer switch SW
TM, output control switch SW
VPIntegrally be arranged in the cooking timer 8 with timer motor 5.Timer motor 5 has a plurality of transmitting gears.The user can set cooking time and power output by timing control handle and output control handle that manipulation is arranged on the matrix.After cooking time and power output are set and are finished, timer SW
TMWith output control switch SW
VPAutomatic complete operation in setting-up time.Correspondingly, as the timer SW that is connected between the cooking room thermometer transducer TCO2 and the second gate controlled switch SW2
TMClosed also through after the setting-up time under the timer motor 5 with gear drives, timer switch SW
TMDisconnect, make power supply can be connected to or break away from illuminating lamp 2, fan electromotor 3 and drive motors 4 etc. like this.
In addition, be connected the first gate controlled switch SW1 and monitor switch SW
MTBetween output control switch SW
VP, as timer switch SW
TMThe same, as under the timer motor-driven, to come controlled microwave stove power output by closed and disconnected circuit termly.Correspondingly, as power output control switch SW
VPDuring disconnection, power supply imports to illuminating lamp 2, drive motors 4 and fan electromotor 4 etc.On the other hand, as output control switch SW
VPWhen closed, power supply imports among the high-tension transformer HVT, and magnetron MGT generation high-frequency impulse comes cooking food like this.
The monitor switch SW
MTAn end link to each other with the primary coil 7a of high-tension transformer HVT, the other end is via monitor fuse FUSE2 and relay switch SW
IRLink to each other.The monitor switch SW
MTBeing parallel to relay coil 6a simultaneously goes up with cut-off/close relay switch SW
IRRelay switch SW
IRPlay the effect of independent relay 6 with relay coil 6a, when it is characterized in that loading external voltage, relay is not an executable operations but through the scheduled time, for example just begin executable operations after the 20-40 millisecond immediately.In addition, relay switch SW
IRCurrent-limiting resistance R2 in parallel.
Current-limiting resistance R2 adopts the colloid resistance with high resistance usually.
Correspondingly, as power connection relay coil 6a and the monitor switch SW
MTWhen closed, relay 6 performance time-lag actions are through closing relay switch after the certain hour.Correspondingly, relay switch SW
IRConnect after surge current exhausts by current-limiting resistance R2, can realize the problem that prevents that operating circuit overload and microwave oven are damaged like this, the surge current with high inverse electromotive force that produces at power supply starting instantaneous high pressure transformer is applied.
Yet, when the monitor switch SW
MTWhen closed path is loaded into relay coil 6a, at this moment, relay switch SW
IRShould become closure state from off-state, and when being in off-state, will occur fortuitous event because of faults itself (because of fusing, faulty operation) when it.When this fortuitous event occurring, alternating current is loaded on the high-tension transformer HVT via current-limiting resistance R2.At this moment because current-limiting resistance R2 is the high value colloid resistance that is used to prevent surge current, its hindrance function within the time (about 30 seconds) will produce heat.Current-limiting resistance R2 is through termination effect afterwards after a while.
Correspondingly, melt because of the heat that current-limiting resistance produces if be installed in electric component that is provided with current-limiting resistance R2 on the printed circuit board (PCB) in the cooking room and the holding wire that is connected various transducers, insulation damages promptly may occur and phenomenon on fire occur, consequently cause product reliability to reduce.
Summary of the invention
Purpose of the present invention mainly is for solving the above-mentioned problems in the prior art.The purpose of this invention is to provide a kind of microwave oven, this microwave oven can be by preventing because the unfailing performance that insulation damages that apparatus failure causes or phenomenon on fire improve microwave oven.
For realizing above-mentioned target, the invention provides a kind of microwave oven, it comprises: AC power; Be used to set the cooking timer of cooking time; Be used for AC power is transported to the relay of high-tension transformer primary coil, this relay comprises relay coil and the relay switch that moves in response to cooking timer; And current-limiting apparatus, it is used for the surge current generation attenuation that produces when loading AC power by relay, and the characteristics of this current-limiting apparatus are that its resistance value increases with the rising of its internal temperature proportionally.
The positive temperature coefficient PTC electro-hot regulator that current-limiting apparatus preferably disconnects when internal temperature is elevated to predetermined temperature, this electro-hot regulator is in parallel with relay switch.
In the optimal way, current-limiting apparatus is configured to surge current is produced attenuation, starts operation to relay switch so that AC power to be provided up to relay coil.
In optimal way, current-limiting apparatus is connected in series to power line so that cooking timer is connected to high-tension transformer, and power line is arranged near the printed circuit board (PCB) that supports electric component and the connecting circuit parts position to the holding wire of printed circuit board (PCB) simultaneously.
In addition, the present invention also provides a kind of microwave oven, and it comprises: AC power; Be used to set the cooking timer of cooking time; Be used in the cooking time that cooking timer is set, AC power being flowed to the power supplier of heater; With the current-limiting apparatus that is used for the surge current generation attenuation that produces when AC power is loaded into relay, its characteristics are that its resistance value increases with the rising of its internal temperature proportionally.
Description of drawings
With reference to the detailed description of following specification and in conjunction with the accompanying drawings, above-mentioned and other target of the present invention and other advantages will obtain more clearly understanding.In the accompanying drawing:
Fig. 1 is the circuit structure diagram of conventional microwave oven.
Fig. 2 is the circuit structure diagram according to a kind of microwave oven of the present invention.
Embodiment
In the accompanying drawing, same reference numerals is represented identical or similar parts in different accompanying drawings.
Fig. 2 is the circuit structure diagram according to a kind of microwave oven of the present invention.
As shown in Figure 2, first, second power line L1, the L2 that is used to import common alternating current AC is connected to the two ends of high-tension transformer HVT primary coil by a noise filter.First power line L1 serial connection: magnetron temperature sensor TCO1, this temperature sensor MGT is overheated to prevent magnetron MGT according to magnetron MGT temperature closure/person's open circuit; The first gate controlled switch SW1, it is according to the unlatching of door of microwave oven or closure/disconnection and the power output of controlled microwave stove and the output control switch SW of monitor switch d of closed condition control circuit
VPIn addition, second source line L2 serial connection: cooking room temperature sensor TCO2, its temperature closure/open circuit according to cooking room is overheated to prevent cooking room; The timer that is used for the cooking time of controlled microwave stove; Be used to prevent the relay switch of surge current and according to second gate controlled switch of the opening and closing state closure/open circuit of door of microwave oven.
Also has timer switch SW
TM, output control switch SW
VPBe arranged in the cooking timer 8 with timer motor integral body.Timer motor 5 has a plurality of transmitting gears.The user can set cooking time and power output by timing control handle and output control handle that adjusting is arranged on the matrix.After cooking time and power output are set and are finished, timer SW
TMWith output control switch SW
VPAt the automatic complete operation of setting-up time.Correspondingly, as the timer SW that is connected between the cooking room thermometer transducer TCO2 and the second gate controlled switch SW2
TMClosed also through after the setting-up time under the timer motor 5 with gear drives, timer SW
TMDisconnect, make power supply can be connected to or break away from illuminating lamp 2, fan electromotor 3 and drive motors 4 etc. like this.
In addition, be connected the first gate controlled switch SW1 and monitor switch SW
MTBetween output control switch SW
VP, as timer, the power output of under the timer motor-driven, coming the controlled microwave stove by closed and disconnected circuit termly.Correspondingly, as power output control switch SW
VPDuring disconnection, power supply imports to illuminating lamp 2, drive motors 4 and fan electromotor 4 etc.On the other hand, as output control switch SW
VPWhen closed, power supply imports among the high-tension transformer HVT, and magnetron MGT generation high-frequency impulse comes cooking food like this.
Control relay SW
MTAn end link to each other with the primary coil 7a of high-tension transformer HVT, the other end is via monitoring fuse FUSE2 and relay switch SW
IRLink to each other.The monitor switch SW
MTBeing parallel to relay coil 6a simultaneously goes up with cut-off/close relay switch SW
IRRelay switch SW
IRPlay the effect of independent relay 6 with relay coil 6a, when it is characterized in that loading external voltage, relay is not an executable operations but through the scheduled time, for example just begin executable operations after the 20-40 millisecond immediately.
In view of above-mentioned part has given explanation in the prior art, no longer it is described in more details at this.
The invention is characterized at relay SW
IRTwo ends positive temperature coefficient (PTC) electro-hot regulator in parallel.
The characteristics of positive temperature coefficient PTC electro-hot regulator are that after its internal temperature reaches certain value electro-hot regulator is because reason is transmitted in the crystal orientation, and its resistance value raises and sharply raises with temperature.
Positive temperature coefficient PTC electro-hot regulator is a kind of n type oxide semiconductor, and it passes through at barium titanate BaTiO
3In add a small amount of rare earth element and have conductivity.By replacing the content of barium Ba can change the Curie temperature of N type oxide semiconductor with strontium Sr or plumbous Pb.
When being loaded into relay coil 6a, goes up and the monitor switch SW power supply
MTWhen closed, relay 6 performance servo actions are through closing relay switch SW after the certain hour
IRCorrespondingly, relay switch SW
IRConnect after surge current is by the decay of positive temperature coefficient electro-hot regulator, can prevent the problem of operating circuit overload like this, the surge current with high inverse electromotive force that produces at power supply starting instantaneous high pressure transformer is applied.
In addition, at relay switch SW
IRDuring the situation that meets accident because of fault, if be loaded on the relay coil 6a monitor switch SW at power supply
MTWhen being in closure state, relay switch SW
IRBe in off-state, AC power is transferred among the high-tension transformer HVT via positive temperature coefficient PTC electro-hot regulator.
Because being its resistance value, the characteristics of positive temperature coefficient PTC electro-hot regulator increase electro-hot regulator automatic disconnection when internal temperature is elevated to uniform temperature (about 100 ℃) with the internal temperature rising.According to this specific character of electro-hot regulator, positive temperature coefficient PTC electro-hot regulator occurred when unexpected in unusual short time, such as disconnected about one second.In other words, even fortuitous event occurs, the electric component or the holding wire that are installed on the printed circuit board (PCB) can not affect adversely yet.
As mentioned above, the invention provides a kind of microwave oven, set in the microwave oven of cooking time and power output the user, it is connecting the positive temperature coefficient PTC electro-hot regulator be used for before the relay switch effect surge current generation attenuation on relay switch.Because the characteristic of positive temperature coefficient PTC electro-hot regulator is that its resistance raises with internal temperature, when even relay switch remains on off-state because of fault, electro-hot regulator will reach after the certain value at internal temperature and disconnect within the short time (about a second), like this, can prevent that apparatus failure from causing the generation of insulation damages or phenomenon on fire, thereby improve the reliability of products energy.
Though the present invention has carried out illustrative open and explanation by preferred embodiment; but will be understood that those skilled in the art may make various changes, increase and alternative on this basis, and can not break away from invention protection range defined by the claims and theme tone.
Claims (7)
1. microwave oven, it comprises:
AC power;
Be used to set the cooking timer of cooking time;
Be used for AC power is transported to the relay of high-tension transformer primary coil, this relay comprises relay coil and the relay switch that moves in response to cooking timer; With
Be used for the current-limiting apparatus to the surge current generation attenuation that produces when AC power is loaded into relay, the characteristics of this current-limiting apparatus are that its resistance value raises with its internal temperature and increases proportionally.
2. microwave oven as claimed in claim 1 is characterized in that described current-limiting apparatus is the positive temperature coefficient PTC electro-hot regulator that internal temperature disconnects when being elevated to predetermined temperature.
3. microwave oven as claimed in claim 1 is characterized in that described current-limiting apparatus is in parallel with relay switch.
4. microwave oven as claimed in claim 3 is characterized in that current-limiting apparatus is configured to surge current is produced attenuation, starts operation to relay switch so that AC power to be provided up to relay coil.
5. microwave oven as claimed in claim 1, it is characterized in that described current-limiting apparatus connects with power line so that cooking timer is connected to high-tension transformer, power line is arranged in abutting connection with the printed circuit board (PCB) that supports electric component and electric component is connected to the position of the holding wire of printed circuit board (PCB) simultaneously.
6. microwave oven, it comprises:
AC power;
Be used to set the cooking timer of cooking time;
Be used in the cooking time that cooking timer is set, AC power being flowed to the power supplier of heater; With
The current-limiting apparatus of the surge current generation attenuation that produces when being used for that AC power is loaded into relay, its characteristics are that its resistance value raises with its internal temperature and increases proportionally.
7. microwave oven as claimed in claim 6 is characterized in that described current-limiting apparatus is the positive temperature coefficient PTC electro-hot regulator that internal temperature disconnects when being elevated to predetermined temperature.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| KR1020020030762A KR20030092915A (en) | 2002-05-31 | 2002-05-31 | Microwave oven |
| KR200230762 | 2002-05-31 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN1463171A true CN1463171A (en) | 2003-12-24 |
Family
ID=29417462
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN02126544A Pending CN1463171A (en) | 2002-05-31 | 2002-07-23 | Microwave oven |
Country Status (3)
| Country | Link |
|---|---|
| EP (1) | EP1367860A3 (en) |
| KR (1) | KR20030092915A (en) |
| CN (1) | CN1463171A (en) |
Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN100339645C (en) * | 2004-01-20 | 2007-09-26 | 三星电子株式会社 | Microwave oven |
| CN102607077A (en) * | 2012-03-29 | 2012-07-25 | 合肥荣事达三洋电器股份有限公司 | Microwave oven start control device and control method |
| CN105591373A (en) * | 2014-10-23 | 2016-05-18 | 中国石油天然气股份有限公司 | Protection circuit of controller |
| TWI580183B (en) * | 2014-07-18 | 2017-04-21 | 松下知識產權經營股份有限公司 | Switch device and load control system ???including the same |
| CN111092545A (en) * | 2019-12-24 | 2020-05-01 | 广东美的白色家电技术创新中心有限公司 | Impulse current suppression device |
Family Cites Families (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| KR970032287A (en) * | 1995-11-10 | 1997-06-26 | 배순훈 | Inrush Current Control Device and Method of Microwave Oven |
| KR19980085394A (en) * | 1997-05-29 | 1998-12-05 | 배순훈 | Inrush current prevention and fire protection device of mechanical microwave oven |
| KR19990002105A (en) * | 1997-06-19 | 1999-01-15 | 배순훈 | Inrush Current Prevention Circuit of Mechanical Microwave |
| US6218652B1 (en) * | 1999-05-29 | 2001-04-17 | Samsung Electronics Co., Ltd. | Apparatus for eliminating inrush current of a microwave oven |
| KR20000075154A (en) * | 1999-05-29 | 2000-12-15 | 윤종용 | Timmer apparatus for a preventing inrush current of a microwave oven |
-
2002
- 2002-05-31 KR KR1020020030762A patent/KR20030092915A/en not_active Application Discontinuation
- 2002-07-11 EP EP02254898A patent/EP1367860A3/en not_active Withdrawn
- 2002-07-23 CN CN02126544A patent/CN1463171A/en active Pending
Cited By (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN100339645C (en) * | 2004-01-20 | 2007-09-26 | 三星电子株式会社 | Microwave oven |
| CN102607077A (en) * | 2012-03-29 | 2012-07-25 | 合肥荣事达三洋电器股份有限公司 | Microwave oven start control device and control method |
| CN102607077B (en) * | 2012-03-29 | 2014-07-30 | 合肥荣事达三洋电器股份有限公司 | Microwave oven start control method |
| TWI580183B (en) * | 2014-07-18 | 2017-04-21 | 松下知識產權經營股份有限公司 | Switch device and load control system ???including the same |
| CN105591373A (en) * | 2014-10-23 | 2016-05-18 | 中国石油天然气股份有限公司 | Protection circuit of controller |
| CN105591373B (en) * | 2014-10-23 | 2019-04-09 | 中国石油天然气股份有限公司 | Protection circuit of controller |
| CN111092545A (en) * | 2019-12-24 | 2020-05-01 | 广东美的白色家电技术创新中心有限公司 | Impulse current suppression device |
| CN111092545B (en) * | 2019-12-24 | 2020-11-17 | 广东美的白色家电技术创新中心有限公司 | Impulse current suppression device |
Also Published As
| Publication number | Publication date |
|---|---|
| KR20030092915A (en) | 2003-12-06 |
| EP1367860A2 (en) | 2003-12-03 |
| EP1367860A3 (en) | 2005-07-06 |
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Legal Events
| Date | Code | Title | Description |
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| C06 | Publication | ||
| PB01 | Publication | ||
| C10 | Entry into substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| C02 | Deemed withdrawal of patent application after publication (patent law 2001) | ||
| WD01 | Invention patent application deemed withdrawn after publication |