CA1068789A - Microwave oven blower interlock circuit - Google Patents
Microwave oven blower interlock circuitInfo
- Publication number
- CA1068789A CA1068789A CA273,812A CA273812A CA1068789A CA 1068789 A CA1068789 A CA 1068789A CA 273812 A CA273812 A CA 273812A CA 1068789 A CA1068789 A CA 1068789A
- Authority
- CA
- Canada
- Prior art keywords
- circuit
- switch
- blower
- mode
- self
- 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.)
- Expired
Links
- 238000010411 cooking Methods 0.000 claims abstract description 41
- 238000004140 cleaning Methods 0.000 claims abstract description 29
- 238000000197 pyrolysis Methods 0.000 claims description 3
- 238000001816 cooling Methods 0.000 abstract description 4
- 238000010438 heat treatment Methods 0.000 description 7
- 230000015556 catabolic process Effects 0.000 description 2
- 238000006731 degradation reaction Methods 0.000 description 2
- 230000007935 neutral effect Effects 0.000 description 2
- 241001481828 Glyptocephalus cynoglossus Species 0.000 description 1
- 239000003990 capacitor Substances 0.000 description 1
- 230000000295 complement effect Effects 0.000 description 1
- 238000013461 design Methods 0.000 description 1
- 238000010586 diagram Methods 0.000 description 1
- 230000009977 dual effect Effects 0.000 description 1
- 238000000034 method Methods 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 238000013021 overheating Methods 0.000 description 1
- 238000012546 transfer Methods 0.000 description 1
- 238000009827 uniform distribution Methods 0.000 description 1
- 238000004804 winding Methods 0.000 description 1
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
- H05B6/647—Aspects related to microwave heating combined with other heating techniques
- H05B6/6482—Aspects related to microwave heating combined with other heating techniques combined with radiant heating, e.g. infrared heating
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F24—HEATING; RANGES; VENTILATING
- F24C—DOMESTIC STOVES OR RANGES ; DETAILS OF DOMESTIC STOVES OR RANGES, OF GENERAL APPLICATION
- F24C14/00—Stoves or ranges having self-cleaning provisions, e.g. continuous catalytic cleaning or electrostatic cleaning
- F24C14/02—Stoves or ranges having self-cleaning provisions, e.g. continuous catalytic cleaning or electrostatic cleaning pyrolytic type
-
- 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
- H05B6/6402—Aspects relating to the microwave cavity
- H05B6/6405—Self-cleaning cavity
-
- 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
- H05B6/6432—Aspects relating to testing or detecting leakage in a microwave heating apparatus
-
- 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
- H05B6/6447—Method of operation or details of the microwave heating apparatus related to the use of detectors or sensors
- H05B6/645—Method of operation or details of the microwave heating apparatus related to the use of detectors or sensors using temperature sensors
Abstract
ABSTRACT OF THE DISCLOSURE
Disclosed herein is an operating circuit for a domestic cooking appliance of the type adapted to perform conventional cooking and microwave cooking in a single, i.e. the same cavity, wherein the circuit includes a blower providing cooling air during both a microwave cooking cycle and a pyrolytic cleaning cycle and a switch responsive to the blower output to prevent operation of the cleaning cycle in the event of failure of the blower.
Disclosed herein is an operating circuit for a domestic cooking appliance of the type adapted to perform conventional cooking and microwave cooking in a single, i.e. the same cavity, wherein the circuit includes a blower providing cooling air during both a microwave cooking cycle and a pyrolytic cleaning cycle and a switch responsive to the blower output to prevent operation of the cleaning cycle in the event of failure of the blower.
Description
~0 6 87 ~9 1 This invention relate~ to domestic cooking appli-ance~, and more specifically, it relates to cooking appliance~
configured to cook food~ through the application of conven ~onal so-called thermal energy or by microwave energy, or by both simultaneously, all of the operations being accomplished in a single, i.e. the ~ame cooking cavity. Cooking by the simultaneous application of thermal energy and microwave energy i9 hereinafter referred to as "combination cooking."
In recent years, domestic cooking appliances, ~uch as kitchen ranges, have commonly included means for cleaning the oven cavity by raising its temperature to a level subs-tantially above that which is normally encountered in cooking.
Such temperatures are generally in excess of about 780F or 400C, and such proce~s is commonly termed pyrolytic self-cleaning.
The de~ign of a domestic cooking appliance in whichconventional, thermal energy cooking and microwave energy cooking can be carried out in the same oven cavity, and wherein the oven cavity can be pyrolytically self-cleaned, p~:e~e~s ~ n~n~er c~ u~ t proD em~, ~ecaUse, in 90me respectst the ~equirement~ for carrying ~t the two method~
of cooking are not entirely compatible one with another.
However, ~t haq alqo been discovered that certain requlre-ments of pyrolytic self-cleaning and o~ microwave cooking can be made complementary, and that certain component~ can be combined to produce a ~ynergism wherein the components perform dual functlons. ~he present invention deals with one such a spect of design.
10687~9 i The pregent invention provides an operating circuit for a domestic cooking appliance equipped to operate ` ln any one of three modes which are a conventional thermal cooking mode, a microwave cooking mode and a self-cleaning mode by pyrolysis. The operating circuit comprises switch means for selecting one of the modes and a motor-driven blower, wherein the blower is operable, upon the selection of either the microwave cooking mode or the self-cleaning mode, to actuate an air-sensing switch which responds to air movement when produced by the blower, the air-sensing switch being coupled in the circuit, so that, when the self-cleaning mode is selected, operation of the cooking appliance in the self-cleaning mode is rendered impossible when the air-sensing switch does not respond to air movement.
The invention will be described in greater detail by reference to the accompanying drawing, which is a schematic diagram of one embodiment of an operating circuit in accordance with the invention.
The operating circuit shown in Figure 1 is in general a standard 3-wire, 240V nominal circuit which consists of linec Ll and L3 and neutral line L2. The general type of circuit is well known and provides a nominal voltage of 120V between either Ll or L3 and the neutral line L2, and a nominal voltage of 240V between lines Ll and L3.
The circuit includes certain elements which may be considered standard and well known in the field of kitchen ranges. Such components include surface light 10 of the fluorescent type with its associated ballast 11 and momentary start switch 12; oven light 13 and oven light switch 14;
mb/~l~ _ 3 _ 1~687~39 oven cavity heating units 20, 21, and 22, and four surface heating units 23, 24, 25, and 26. The oven cavity heating unit~ are of a standard resistance heater type and various wattages may be selected and employed depending upon the function to be performed by the particular unit or element.
In the illustrated circuit, heating unit 20 is assumed to be an element used for broiling, unit 22 an element for providing heat during baking, and unit 21 is an auxiliary heating unit used to provide additional heating during a pyrolytic self-cleaning cycle and can also be used in baking.
As has been indicated above, the circuit illustrateS
the electrical operation of a cooking appliance which is adapted to perform a number of cooking functions.
These functions include the various types of thermal cooking, such as baking and broiling, cooking with microwave energy alone or with a combination of microwave and thermal energy, and pyrolytic self-cleaning. Means are provided for selecting one of the aforementioned modes of operation of functions. In the circuit of the drawing, the selecting means are preferably consolidated into a single selector switch having multiple contacts 31A, 31B, 31C, 31D, 31E, and 31F. The function of each set of contacts is discussed more fully herein below.
The circuit also includes means for generating microwave energy, including a magnetron 50, a transformer 51, a capacitor 52, and a diode 53. In the particular circuit shown the components are electrically connected to form a half-wave voltage doubler circuit but it will be understood that other magnetron power supply circuit configurations could be substituted for the half-wave voltage doubler, without departing from the scope of the invention.
10687~9 In addition to the power supply components, the microwave portion of the circuit also includes a stirrer motor 48 which is used to drive a rotatable stirrer to provide a more uniform distribution of microwave energy within the cooking cavity. In order to insure that the appliance is not used in the microwave mode unless the door is securely fastened, interlock switches 32 and 33 are provided and physically configured to assume a closed position in conjunction with the closing of the oven door.
The power supply component~ used in microwave ovens are subject to degradation and shortened life when subjected to excessive heat, not unlike many other electrical components. In the cooking appliance illustrated a fan or blower is used to provide cooling of the components, the blower being driven by blower motor 41. It is desirable to operate the blower motor 41 during two distinct cycles or modes of operation of the range, namely, during microwave cooking when the microwave components themselves are heat generators, and during the pyrolytic self-cleaning cycle when the areas adjacent the oven cavity may be at abnormally high temperatures.
In order to operate the circuit shown in the drawing in a microwave cooking mode, the appliance door is closed, closing interlock switches 32 and 33. Some operating time duration is selected by the operator, which may vary frcm a few seconds to several minute~. The entry of the selected time duration closes timer switch 46 thereby to supply power to timer motor 45. Lock switch 34 is normally closed on the upper contact, as shown in the drawing, except in the cleaning cycle, as is described more fully herein below.
~1687&~9 The selection of the microwave mode closes contactq 31F of the selector switch. Thus, it can be seen that a circuit is completed from Ll through switches 32, 34, 33, 46, and 31F
to the microwave power components such as the primary winding of transformer 51 and to L2. Since switch 40 is closed on the lower contact, as shown in the drawing, power is supplied to blower motor 41, providing cooling to the microwave components.
As has been pointed out above, it is also desirable to operate motor 41 during the pyrolytic self-cleaning cycle, and the operation of that cycle with regard to the circuit shown in the drawing will now be described. It will be appreciated that during such cleaning cycle temperatures in excess of 700F are common, well above those normally encoun-tered in cooking. It is therefore desirable to provide means for preventing the opening of the oven during the period when such temperatures have been reached, and the present invention provides a circuit having that capability.
As is the case in the microwave sequence of operation described above, the closing of the oven door causes interlock switches 32 and 33 to be closed, allowing power to lock switch 34. The mode selector is then operated to select the cleaning mode by appropriately positioning the selector switch.
This closes switch 31E to its upper contact, supplying power to lock motor 60. In addition, the remaining contacts of the mode selector are thereby positioned as follows: Switch 31A
is closed to the left contact shown, ~witch 31B to its lower contact, switch 31C is closed, switch 31D to its left contact, and switch 31F is open.
The lock motor 60 is energized to mechanically i~e.
1C96~;~39 automatically position a door lock device, the movement of the lock mechanism also being employed to operate a further sequence of switches. Specifically, switch 40 is transferred to the upper contact shown in the drawing, and lock switch 34 is transferred to the lower contact. The closing of switches 40 and 34, as described, completes the circuit for blower motor 41 through switches 32, 34, and 40. The transfer of lock switch 34 also interrupts the power to lock motor 60, leaving the oven in the locked position.
Upon energization of blower motor 41, the blower is placed into operation to provide a flow of cooling air for the microwave generating components. A sensing switch 35 is provided, adapted to respond to the output of the blower.
For example, switch 35 is preferably a sail switch placed in the path of the moving air from the blower. As the blower comes up to speed and delivers its rated output, switch 35 is thereby closed.
In order to complete the cleaning cycle, a period of time is set on the oven timer, thereby closing the timer contacts sho~n as switch 37 in the drawing. In addition, the contacts 65 of the oven thermostat as well as contacts 38 of the cleaning cycle thermostat are closed. Power is supplied through the circuit thus closed to heating elements 21 and 22 to provide heat for pyrolytic cleaning.
In order to increase the safety of the circuit, an additional thermostat is provided, the contacts of which are shown at 36 in the drawing. The thermostat is configured to open the contacts upon reaching a preselected temperature such as 560 F, thereby interrupting the circuit to lock motor 60, so that it cannot be operated into the unlocked position, 1C~687~9 as long as the oven temperature remains above the selected temperature.
Various other components of the circuit have been shown for clarity and completeness including range timer motor 42, thermal relays ~and 64, and various indicator lights 18, 61, 62, and 47.
Thus the circuit, as shown in the drawing and described herein, provides for the electrical operation of a combination cooking range adapted to perate in a number of different modes, the particular mode being selected and determined by the positioning of contacts 31A-F according to the rotation of the mode selector. The circuit provides for the operation of blower motor 41 only upon the selection of either the microwave cooking mode or the cleaning mode, which is accomplished through a simple switching network without the need for expensive components, such as relays and the like. Moreover, switch 35 insures that blower motor 41 is functioning before the cleaning cycle can be completed, thus preventing serious overheating and quality degradation of the expensive microwave components.
While the circuit has thus been described in concider-able detail, it will be understood that such description is to be construed as illustrative and not intended to limit the scope of the invention which is defined by the appended claims.
Those skilled in the art will appreciate that various modifi-cations can be made without departing from the spirit or scope of that invention.
configured to cook food~ through the application of conven ~onal so-called thermal energy or by microwave energy, or by both simultaneously, all of the operations being accomplished in a single, i.e. the ~ame cooking cavity. Cooking by the simultaneous application of thermal energy and microwave energy i9 hereinafter referred to as "combination cooking."
In recent years, domestic cooking appliances, ~uch as kitchen ranges, have commonly included means for cleaning the oven cavity by raising its temperature to a level subs-tantially above that which is normally encountered in cooking.
Such temperatures are generally in excess of about 780F or 400C, and such proce~s is commonly termed pyrolytic self-cleaning.
The de~ign of a domestic cooking appliance in whichconventional, thermal energy cooking and microwave energy cooking can be carried out in the same oven cavity, and wherein the oven cavity can be pyrolytically self-cleaned, p~:e~e~s ~ n~n~er c~ u~ t proD em~, ~ecaUse, in 90me respectst the ~equirement~ for carrying ~t the two method~
of cooking are not entirely compatible one with another.
However, ~t haq alqo been discovered that certain requlre-ments of pyrolytic self-cleaning and o~ microwave cooking can be made complementary, and that certain component~ can be combined to produce a ~ynergism wherein the components perform dual functlons. ~he present invention deals with one such a spect of design.
10687~9 i The pregent invention provides an operating circuit for a domestic cooking appliance equipped to operate ` ln any one of three modes which are a conventional thermal cooking mode, a microwave cooking mode and a self-cleaning mode by pyrolysis. The operating circuit comprises switch means for selecting one of the modes and a motor-driven blower, wherein the blower is operable, upon the selection of either the microwave cooking mode or the self-cleaning mode, to actuate an air-sensing switch which responds to air movement when produced by the blower, the air-sensing switch being coupled in the circuit, so that, when the self-cleaning mode is selected, operation of the cooking appliance in the self-cleaning mode is rendered impossible when the air-sensing switch does not respond to air movement.
The invention will be described in greater detail by reference to the accompanying drawing, which is a schematic diagram of one embodiment of an operating circuit in accordance with the invention.
The operating circuit shown in Figure 1 is in general a standard 3-wire, 240V nominal circuit which consists of linec Ll and L3 and neutral line L2. The general type of circuit is well known and provides a nominal voltage of 120V between either Ll or L3 and the neutral line L2, and a nominal voltage of 240V between lines Ll and L3.
The circuit includes certain elements which may be considered standard and well known in the field of kitchen ranges. Such components include surface light 10 of the fluorescent type with its associated ballast 11 and momentary start switch 12; oven light 13 and oven light switch 14;
mb/~l~ _ 3 _ 1~687~39 oven cavity heating units 20, 21, and 22, and four surface heating units 23, 24, 25, and 26. The oven cavity heating unit~ are of a standard resistance heater type and various wattages may be selected and employed depending upon the function to be performed by the particular unit or element.
In the illustrated circuit, heating unit 20 is assumed to be an element used for broiling, unit 22 an element for providing heat during baking, and unit 21 is an auxiliary heating unit used to provide additional heating during a pyrolytic self-cleaning cycle and can also be used in baking.
As has been indicated above, the circuit illustrateS
the electrical operation of a cooking appliance which is adapted to perform a number of cooking functions.
These functions include the various types of thermal cooking, such as baking and broiling, cooking with microwave energy alone or with a combination of microwave and thermal energy, and pyrolytic self-cleaning. Means are provided for selecting one of the aforementioned modes of operation of functions. In the circuit of the drawing, the selecting means are preferably consolidated into a single selector switch having multiple contacts 31A, 31B, 31C, 31D, 31E, and 31F. The function of each set of contacts is discussed more fully herein below.
The circuit also includes means for generating microwave energy, including a magnetron 50, a transformer 51, a capacitor 52, and a diode 53. In the particular circuit shown the components are electrically connected to form a half-wave voltage doubler circuit but it will be understood that other magnetron power supply circuit configurations could be substituted for the half-wave voltage doubler, without departing from the scope of the invention.
10687~9 In addition to the power supply components, the microwave portion of the circuit also includes a stirrer motor 48 which is used to drive a rotatable stirrer to provide a more uniform distribution of microwave energy within the cooking cavity. In order to insure that the appliance is not used in the microwave mode unless the door is securely fastened, interlock switches 32 and 33 are provided and physically configured to assume a closed position in conjunction with the closing of the oven door.
The power supply component~ used in microwave ovens are subject to degradation and shortened life when subjected to excessive heat, not unlike many other electrical components. In the cooking appliance illustrated a fan or blower is used to provide cooling of the components, the blower being driven by blower motor 41. It is desirable to operate the blower motor 41 during two distinct cycles or modes of operation of the range, namely, during microwave cooking when the microwave components themselves are heat generators, and during the pyrolytic self-cleaning cycle when the areas adjacent the oven cavity may be at abnormally high temperatures.
In order to operate the circuit shown in the drawing in a microwave cooking mode, the appliance door is closed, closing interlock switches 32 and 33. Some operating time duration is selected by the operator, which may vary frcm a few seconds to several minute~. The entry of the selected time duration closes timer switch 46 thereby to supply power to timer motor 45. Lock switch 34 is normally closed on the upper contact, as shown in the drawing, except in the cleaning cycle, as is described more fully herein below.
~1687&~9 The selection of the microwave mode closes contactq 31F of the selector switch. Thus, it can be seen that a circuit is completed from Ll through switches 32, 34, 33, 46, and 31F
to the microwave power components such as the primary winding of transformer 51 and to L2. Since switch 40 is closed on the lower contact, as shown in the drawing, power is supplied to blower motor 41, providing cooling to the microwave components.
As has been pointed out above, it is also desirable to operate motor 41 during the pyrolytic self-cleaning cycle, and the operation of that cycle with regard to the circuit shown in the drawing will now be described. It will be appreciated that during such cleaning cycle temperatures in excess of 700F are common, well above those normally encoun-tered in cooking. It is therefore desirable to provide means for preventing the opening of the oven during the period when such temperatures have been reached, and the present invention provides a circuit having that capability.
As is the case in the microwave sequence of operation described above, the closing of the oven door causes interlock switches 32 and 33 to be closed, allowing power to lock switch 34. The mode selector is then operated to select the cleaning mode by appropriately positioning the selector switch.
This closes switch 31E to its upper contact, supplying power to lock motor 60. In addition, the remaining contacts of the mode selector are thereby positioned as follows: Switch 31A
is closed to the left contact shown, ~witch 31B to its lower contact, switch 31C is closed, switch 31D to its left contact, and switch 31F is open.
The lock motor 60 is energized to mechanically i~e.
1C96~;~39 automatically position a door lock device, the movement of the lock mechanism also being employed to operate a further sequence of switches. Specifically, switch 40 is transferred to the upper contact shown in the drawing, and lock switch 34 is transferred to the lower contact. The closing of switches 40 and 34, as described, completes the circuit for blower motor 41 through switches 32, 34, and 40. The transfer of lock switch 34 also interrupts the power to lock motor 60, leaving the oven in the locked position.
Upon energization of blower motor 41, the blower is placed into operation to provide a flow of cooling air for the microwave generating components. A sensing switch 35 is provided, adapted to respond to the output of the blower.
For example, switch 35 is preferably a sail switch placed in the path of the moving air from the blower. As the blower comes up to speed and delivers its rated output, switch 35 is thereby closed.
In order to complete the cleaning cycle, a period of time is set on the oven timer, thereby closing the timer contacts sho~n as switch 37 in the drawing. In addition, the contacts 65 of the oven thermostat as well as contacts 38 of the cleaning cycle thermostat are closed. Power is supplied through the circuit thus closed to heating elements 21 and 22 to provide heat for pyrolytic cleaning.
In order to increase the safety of the circuit, an additional thermostat is provided, the contacts of which are shown at 36 in the drawing. The thermostat is configured to open the contacts upon reaching a preselected temperature such as 560 F, thereby interrupting the circuit to lock motor 60, so that it cannot be operated into the unlocked position, 1C~687~9 as long as the oven temperature remains above the selected temperature.
Various other components of the circuit have been shown for clarity and completeness including range timer motor 42, thermal relays ~and 64, and various indicator lights 18, 61, 62, and 47.
Thus the circuit, as shown in the drawing and described herein, provides for the electrical operation of a combination cooking range adapted to perate in a number of different modes, the particular mode being selected and determined by the positioning of contacts 31A-F according to the rotation of the mode selector. The circuit provides for the operation of blower motor 41 only upon the selection of either the microwave cooking mode or the cleaning mode, which is accomplished through a simple switching network without the need for expensive components, such as relays and the like. Moreover, switch 35 insures that blower motor 41 is functioning before the cleaning cycle can be completed, thus preventing serious overheating and quality degradation of the expensive microwave components.
While the circuit has thus been described in concider-able detail, it will be understood that such description is to be construed as illustrative and not intended to limit the scope of the invention which is defined by the appended claims.
Those skilled in the art will appreciate that various modifi-cations can be made without departing from the spirit or scope of that invention.
Claims (4)
PROPERTY OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:
1. Operating circuit for a domestic cooking appliance equipped to operate in any one of three modes which are a conventional thermal cooking mode, a microwave cooking mode and a self-cleaning mode by pyrolysis, the operating circuit comprising switch means for selecting one of the modes and a motor-driven blower, wherein the blower is operable, upon the selection of either the microwave cooking mode or the self-cleaning mode, to actuate an air-sensing switch which responds to air movement when produced by the blower, the air-sensing switch being coupled in the circuit, so that, when the self-cleaning mode is selected, operation of the cooking appliance in the self-cleaning mode is rendered impossible when the air-sensing switch does not respond to air movement.
2. Circuit according to Claim 1, wherein the air-sensing switch is a sail having a sail portion located within the output flow of the blower.
3. Circuit according to Claim 1 or Claim 2, wherein the selecting means has a selection state for selecting a thermal baking mode and a selection state for a thermal broiling mode.
4. An operating circuit for a domestic cooking appliance of the type adapted to perform both conventional thermal cooking and microwave cooking in a common cavity, and further adapted to perform self-cleaning by pyrolysis, said circuit including a first switch having first and second positions, said first position placing said switch in a microwave cooking mode circuit and said second position placing said
4. An operating circuit for a domestic cooking appliance of the type adapted to perform both conventional thermal cooking and microwave cooking in a common cavity, and further adapted to perform self-cleaning by pyrolysis, said circuit including a first switch having first and second positions, said first position placing said switch in a microwave cooking mode circuit and said second position placing said
Claim 4...continued.
switch in a self-cleaning mode circuit, each of said first and second positions of said switch adapted to cause energization of a blower in a closed circuit condition; second switch means responsive to the output of said blower, said second switch being located in said self-cleaning mode circuit, said second switch being open when said blower is not operating, whereby said self-cleaning mode circuit cannot be closed in the event said blower is not operating.
switch in a self-cleaning mode circuit, each of said first and second positions of said switch adapted to cause energization of a blower in a closed circuit condition; second switch means responsive to the output of said blower, said second switch being located in said self-cleaning mode circuit, said second switch being open when said blower is not operating, whereby said self-cleaning mode circuit cannot be closed in the event said blower is not operating.
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US71781776A | 1976-08-26 | 1976-08-26 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1068789A true CA1068789A (en) | 1979-12-25 |
Family
ID=24883615
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA273,812A Expired CA1068789A (en) | 1976-08-26 | 1977-03-11 | Microwave oven blower interlock circuit |
Country Status (5)
| Country | Link |
|---|---|
| AU (1) | AU500177B2 (en) |
| CA (1) | CA1068789A (en) |
| DE (1) | DE2715768C2 (en) |
| FR (1) | FR2363060A1 (en) |
| GB (1) | GB1529561A (en) |
Families Citing this family (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP0358344B1 (en) * | 1988-09-09 | 1994-03-30 | Microwave Ovens Limited | Microwave ovens |
| US4954694A (en) * | 1989-01-31 | 1990-09-04 | Matsushita Electric Industrial Co., Ltd. | Cooking oven having function to automatically clean soils attached to inner walls thereof |
| DE3910585A1 (en) * | 1989-04-01 | 1990-10-04 | Buderus Kuechentechnik | Circuit arrangement for a cooking device |
| CN111748364B (en) * | 2020-07-17 | 2021-08-03 | 安徽林农时代科技有限公司 | Solid fuel spiral dry distillation machine |
| CN114690811B (en) * | 2020-12-29 | 2024-04-19 | 广东美的厨房电器制造有限公司 | Temperature control circuit and household appliance |
Family Cites Families (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE1854107U (en) * | 1962-03-30 | 1962-06-28 | Ernst Heinkel Flugzeugbau G M | ELECTRIC WARM AIR GENERATOR. |
| FR2112685A5 (en) * | 1970-11-06 | 1972-06-23 | Scholtes Ets Eugen | |
| DE2341574A1 (en) * | 1973-08-17 | 1975-02-27 | Jega Friedrichsthaler Eisen | ELECTRICAL CIRCUIT FOR A COMBINED ELECTRIC OVEN WITH RESISTANCE HEATING, WITH HF COOKING DEVICE AND WITH DEVICE FOR PYROLYTIC SELF-CLEANING |
-
1977
- 1977-03-11 CA CA273,812A patent/CA1068789A/en not_active Expired
- 1977-03-25 AU AU23654/77A patent/AU500177B2/en not_active Expired
- 1977-04-07 DE DE19772715768 patent/DE2715768C2/en not_active Expired
- 1977-04-07 FR FR7710581A patent/FR2363060A1/en active Granted
- 1977-06-17 GB GB2552177A patent/GB1529561A/en not_active Expired
Also Published As
| Publication number | Publication date |
|---|---|
| DE2715768A1 (en) | 1978-03-09 |
| FR2363060B1 (en) | 1982-02-19 |
| DE2715768C2 (en) | 1983-03-24 |
| AU2365477A (en) | 1978-09-28 |
| AU500177B2 (en) | 1979-05-10 |
| FR2363060A1 (en) | 1978-03-24 |
| GB1529561A (en) | 1978-10-25 |
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