WO2014075922A1

WO2014075922A1 - A food preparation appliance operated on an induction heating cooktop

Info

Publication number: WO2014075922A1
Application number: PCT/EP2013/072700
Authority: WO
Inventors: Sefa Hazir; Onur Yaman; Ahmet Yorukoglu; Ahmet SOZEN
Original assignee: Arcelik Anonim Sirketi
Priority date: 2012-11-14
Filing date: 2013-10-30
Publication date: 2014-05-22
Also published as: EP2921032A1

Abstract

The present invention relates to an appliance (1 ) suitable to be operated wirelessly on an induction heating cooktop (19) having one or more than one induction coil (20), comprising a ferromagnetic base (2) enabling the appliance (1 ) to be heated with the magnetic energy transmitted by the induction coil (20), one or more than one receiver coil (3) that is integrated with the base (2) and that partially receives the power generated by the induction coil (20), a cooking pot (4) wherein food cooking or mixing operations are performed, (20), a mixing or chopping apparatus (6) providing the mixing, blending, chopping or grinding of the foods in the cooking pot (4) in accordance with the user preferences, a mixer motor (5) that rotates the mixing or chopping apparatus (6), a microcontroller (7) that provides the controlling and monitoring of operating parameters such as the cooking temperature, cooking duration and the mixer motor (5) speed, and a user interface (8) having a display and a keypad.

Description

A FOOD PREPARATION APPLIANCE OPERATED ON AN INDUCTION HEATING COOKTOP

The present invention relates to a food preparation appliance, with a mixer situated thereon, that is operated wirelessly on the induction heating cooktop.

In some embodiments, a mixer motor is disposed on the food preparation appliances that are operated on the induction heating cooktop with the principle of wireless power transfer. By means of a mixing apparatus like paddle or blade rotated by a mixer motor the mixing, blending, chopping etc. of the foods in the cooking pot is provided. The electrical power required for operating the mixer motor is supplied by the receiver coil disposed on the base of the food preparation appliance from the induction coil in the induction heating cooktop. The electrical power received by the receiver coil from the induction coil is not sufficient for mixer motor especially in operations that require high speed and high torque. Furthermore, the power scale setting, in other words the heating setting, of the induction heating cooktop should be increased for the operation of the mixer motor. Increase in the power received from the induction coil results in unnecessary and undesired temperature increase and loss of power, increasing energy consumption in the mixing, blending and chopping operations wherein only the mixer motor of the food preparation appliance is desired to be operated.

In the United States Patent No. US3761668, the explanation is given for electrical kitchen appliances that are operated wirelessly on counter-top induction surface cooking units.

In the Japanese Patent Application No. JP9115660, an induction heating cooking appliance is explained wherein the foods contained therein are automatically agitated, preventing burning or heating irregularly.

The International Patent Application No. WO9941950 relates to a cooking vessel that is used in induction heating cooktops.

The aim of the present invention is the realization of a food preparation appliance that is operated wirelessly on the induction heating cooktop, controlled by communicating with the induction heating cooktop, comprising a mixer motor, wherein the mixer motor is operated with the energy supplied from the induction coil and energy consumption is decreased.

The food preparation appliance (will be referred to as “appliance” hereinafter) realized in order to attain the aim of the present invention, explicated in the first claim and the respective claims thereof, is operated wirelessly on an induction heating cooktop (will be referred to as “cooktop” hereinafter). The appliance, wherein the cooking process is performed, has a ferromagnetic base and moreover, the mixing, blending, chopping operations are performed inside the cooking pot by means of a mixer motor (will be referred to as “motor” hereinafter).

The appliance comprises a microcontroller that provides controlling and monitoring of the operation parameters like the cooking temperature, cooking duration, motor speed, and a user interface and communication means that provide communication with the cooktop. A receiver coil situated at the base of the appliance supplies the energy for the motor, the microcontroller, the user interface and the communication means from the induction coil of the cooktop.

The appliance of the present invention comprises a resonant capacitor connected in parallel to the receiver coil and when the motor is operated, the resonant capacitor is activated by means of a switching element, providing the receiver coil to receive almost the entire magnetic energy transmitted by the induction coil at minimum power scale settings that do not heat the cooking pot and to supply the motor. The communication means in the appliance that provide communication with the cooktop transmit the motor operation command entered from the user interface to the cooktop microprocessor and the power transferred from the induction coil to the appliance is decreased while the frequency is increased.

In an embodiment of the present invention, the induction coil transfers power at a lower level than the minimum heating setting used in normal heating operations and at a higher frequency than the minimum heating setting for operating the motor. The capacitance of the resonant capacitor is selected such that the frequency generated by the receiver coil overlaps with the high frequency generated by the induction coil at low power settings that do not heat the cooking pot.

In another embodiment of the present invention, the appliance comprises a motor speed setting switch, connected to the microcontroller, that provides the motor speed to be changed depending on the settings entered via the user interface.

In another embodiment of the present invention, the motor is direct current (DC) type and the AC voltage generated by the receiver coil is converted to DC voltage by a rectifier. A motor feeding capacitor is disposed at the outlet of the rectifier. The rectifier is used in common for the motor, the microcontroller and the user interface.

In another embodiment of the present invention, the appliance comprises a DC - DC converter that converts the high level DC voltage at the outlet of the rectifier into low level DC voltage required for the microcontroller and the user interface. A buffer capacitor is disposed prior to the DC - DC converter and a diode isolator between the rectifier and the DC - DC converter, that protects the microcontroller and the user interface against voltage drops resulting from sudden high currents drawn by the motor.

In another embodiment of the present invention, the motor is of alternative current (AC) type.

In another embodiment of the present invention, the voltage generated by the receiver coil is measured with a voltage measuring unit at the outlet of the receiver coil, the switching element is actuated in accordance with the feedback from the voltage measuring unit and the resonant capacitor is activated or deactivated depending on the voltage level desired to be decreased/increased.

In the appliance of the present invention, the receiver coil at the base of the appliance generates the maximum voltage required for operating the motor by means of the resonant capacitor that is activated by the switching element during operation of the motor. The operations wherein the motor operates at high speed and/or high torque are performed at the minimum power level of the cooktop induction coil, the cooking pot does not heat up and energy saving is provided.

The appliance realized in order to attain the aim of the present invention is illustrated in the attached figure, where:

Figure 1 – is the schematic view of an appliance with cooking and mixing functions operated on an induction heating cooktop.

The elements illustrated in the figure are numbered as follows:

Appliance
Base
Receiver coil
Cooking pot
Motor
Mixing or chopping apparatus
Microcontroller
User interface
Resonant capacitor
Switching element
Communication means
Rectifier
Motor feeding capacitor
Motor speed setting switch
DC - DC converter
Buffer capacitor
Diode isolator
Voltage measuring unit
Cooktop
Induction coil
Power converter
Microprocessor

The food preparation appliance (1) (will be referred to as “appliance (1)” hereinafter) suitable to be operated wirelessly on an induction heating cooktop (19) (will be referred to as “cooktop (19)” hereinafter) having one or more than one induction coil (20), a power converter (21) that operates the induction coil (20) and a microprocessor (22) that controls the operation of the power converter (21), comprises a ferromagnetic base (2) enabling the appliance (1) to be heated with the magnetic energy transmitted by the induction coil (20), one or more than one receiver coil (3) that is integrated with the base (2) and that partially receives the power generated by the induction coil (20), a cooking pot (4) wherein food cooking and/or mixing, blending, chopping, etc. operations are performed, a mixer motor (5) (will be referred to as “motor (5)” hereinafter) providing the mixing, blending, chopping or grinding of the foods in the cooking pot (4) in accordance with the user preferences, a mixing or chopping apparatus (6) connected to the motor (5), a microcontroller (7) that provides the controlling and monitoring of operating parameters such as the cooking temperature, cooking duration and the motor (5) speed, and a user interface (8) having a display and a keypad.

The appliance (1) of the present invention comprises a resonant capacitor (9) connected in parallel to the receiver coil (3) and a switching element (10) that is connected in series to the resonant capacitor (9), that is controlled by the microcontroller (7), that activates the resonant capacitor (9) when the motor (5) is operated by means of the user interface (8) for food mixing, blending or chopping operations, enabling the receiver coil (3) to receive almost all of the magnetic energy transmitted by the induction coil (20) at low power setting that does not heat the cooking pot (4) and to feed the motor (5).

In an embodiment of the present invention, the appliance (1) comprises one or more than one communication means (11) that provides communication with the cooktop (19) and the microcontroller (7) that delivers the operating command of the motor (5), entered from the user interface (8) or determined by the cooking profiles in the memory of the microcontroller (7), to the microprocessor (22) of the cooktop (19) by the communication means (11) and provides increase in the frequency by decreasing the power transmitted by the induction coil (20) to the appliance (1).

The microcontroller (7) enables the induction coil (20) to transmit power at a lower level than the minimum heating setting used in normal heating operations and at a higher frequency than the frequency in the minimum heating setting for operating the motor (5).

In an embodiment of the present invention, the capacitance (C) of the resonant capacitor (9) is selected such that the frequency formed by the receiver coil (3) and the resonant capacitor (9) overlap with the high frequency formed by the induction coil (20) at low power scales that do not heat the cooking pot (4).

In the appliance (1) of the present invention, the resonant capacitor (9) that is activated while the motor (5) is being operated establishes an LC circuit with the receiver coil (3). The frequency generated by the receiver coil (3) is equalized to the high frequency generated by the induction coil (20) in low power transfer. The capacitance (C) of the resonant capacitor (9) is selected according to the formula F = 1/ (2 * PI * sqrt (LC)) so as to be equalized to the frequency value generated by the induction coil (20) in low power transfer, depending on the inductance (L) determined by the number of windings and diameter of the winding coil of the receiver coil (3). When the frequency values generated by the receiver coil (3) and the induction coil (20) overlap, the receiver coil (3) draws power from the induction coil (20) at the maximum level. The magnetic energy transmitted by the induction coil (20) is transferred to the receiver coil (3) for operating the motor (5) at the desired power level. The receiver coil (3) draws almost all the power, for example 75 - 100 W, transferred from the induction coil (20) and generates the voltage required for the motor (5).

The cooktop (19) operates in the frequency range of for example 20 kHz (2000W) - 50 kHz (150W) for normal heating operations. When the motor (5) is operated by means of the user interface (8), the microprocessor (22) of the cooktop (19) enables the induction coil (20) to transfer power at a lower value (for example 75 - 100W) than the minimum power (for example 150 W) used in heating. This low power is transferred at a higher frequency (for example 70 kHz) than the frequency value (for example 50 kHz) at the minimum power in normal heating. The high frequency low power transferred from the induction coil (20) to the receiver coil (3) only operates the motor (5) but does not heat the cooking pot (4). For example, in mixing operations with “heating” such as soup making, the power scale of the cooktop (19) is increased, high power (for example 150W - 2000W) is transferred from the induction coil (20) to the appliance (1) and the power required for operation of the motor (5) is easily supplied by the receiver coil (3).

In another embodiment of the present invention, the motor (5) is of direct current (DC) type and the appliance (1) comprises a rectifier (12) that converts AC voltage generated by the receiver coil (3) to DC voltage and a motor feeding capacitor (13) disposed at the outlet of the rectifier (12) and stabilizing the DC voltage feeding the motor (5).

In another embodiment of the present invention, the appliance (1) comprises a motor speed setting switch (14) connected to the microcontroller (7), that provides the speed of the motor (5) to be changed depending on the various food preparation commands like mixing, blending, chopping, etc. entered from the user interface (8).

In another embodiment of the present invention, the microcontroller (7) and the user interface (8) are energized by the DC voltage at the outlet of the rectifier (12).

In another embodiment of the present invention, the appliance (1) comprises a DC – DC converter (15), better known as a switched mode power supply (SMPS), that converts the high level DC voltage at the outlet of the rectifier (12) to low level DC voltage required for the microcontroller (7) and the user interface (8). The receiver coil (3) generates AC voltage with the power drawn from the induction coil (20) and the rectifier (12) converts AC voltage to DC voltage. The microcontroller (7) and the user interface (8) require low level DC voltage and the DC – DC converter (15) reduces the high level DC voltage at the outlet of the rectifier (12) to a low level like 5 VDC for the microcontroller (7) and the user interface (8).

In this embodiment, the appliance (1) furthermore comprises a buffer capacitor (16) and a diode isolator (17) disposed prior to the DC – DC converter (15), that protect the microcontroller (7) and the user interface (8) from voltage decreases resulting from sudden drawing of current by the motor (5).

In the appliance (1) of the present invention, the rectifier (12) is used commonly for the motor (5), the microcontroller (7) and the user interface (8). The motor feeding capacitor (13) stabilizes the DC voltage at the outlet of the rectifier (12) for the motor (5). The buffer capacitor (16) stabilizes the DC voltage prior to the DC – DC converter (15), that feeds the microcontroller (7) and the user interface (8), thereby providing the microcontroller (7) and the user interface (8) to be fed with low level, constant, and uninterrupted DC voltage.

In another embodiment of the present invention, the motor (5) is of alternative current (AC) universal type and the motor (5) is operated with the AC voltage generated by the receiver coil (3). In this embodiment, the rectifier (12) is used only for the microcontroller (7) and the user interface (8).

In another embodiment of the present invention, the appliance (1) comprises a voltage measuring unit (18) disposed at the outlet of the receiver coil (3), connected to the microcontroller (7) and measuring the voltage generated by the receiver coil (3).

The microcontroller (7) provides the activation or deactivation of the resonant capacitor (9) depending on the voltage level desired to be decreased/increased, by actuating the switching element (10) according to the feedback from the voltage measuring unit (18) in situations of power scale setting changes, voltage fluctuations of AC mains voltage that operates the induction coil (20) and variable power requirements of the microcontroller (7) and the user interface (8).

In the appliance (1) of the present invention, the receiver coil (3) generates the maximum voltage (for example 220VAC) required for the motor (5), in energy transfer of the induction coil (20) at minimum power level, by means of the resonant capacitor (9) that is activated by the switching element (10) during the operation of the motor (5). The motor (5) is operated without heating the cooking pot (4) and the foods in the cooking pot (4) are provided to be mixed, blended or chopped. The operations of mixing, blending wherein the motor (5) operates at high speed or chopping, grinding operations wherein high torque is applied are performed at the minimum power level of the induction coil (20) of the cooktop (19) and energy saving is provided.

It is to be understood that the present invention is not limited by the embodiments disclosed above and a person skilled in the art can easily introduce different embodiments. These should be considered within the scope of the protection postulated by the claims of the present invention.

Claims

An appliance (1) suitable to be operated wirelessly on a cooktop (19), having one or more than one induction coil (20), a power converter (21) that operates the induction coil (20) and a microprocessor (22) that controls the operation of the power converter (21), comprising a ferromagnetic base (2), one or more than one receiver coil (3) that partially receives the power generated by the induction coil (20), a cooking pot (4) wherein food cooking and/or mixing, blending, chopping operations are performed, a motor (5) providing the mixing, blending, chopping of the foods in the cooking pot (4), a mixing or chopping apparatus (6), a microcontroller (7) that provides the controlling and monitoring of operating parameters such as the cooking temperature, cooking duration and the motor (5) speed, and a user interface (8), characterized in that a resonant capacitor (9) connected in parallel to the receiver coil (3) and a switching element (10) that is controlled by the microcontroller (7), that activates the resonant capacitor (9) when the motor (5) is operated, enabling the receiver coil (3) to receive almost all the magnetic energy transferred by the induction coil (20) at low power setting that does not heat the cooking pot (4) and to feed the motor (5).
An appliance (1) as in Claim 1, characterized in that one or more than one communication means (11) that provides communication with the cooktop (19) and in that the microcontroller (7) that delivers the motor (5) operating command, entered from the user interface (8), to the microprocessor (22) of the cooktop (19) by the communication means (11) and provides increase in the frequency by decreasing the power transmitted to the appliance (1) by the induction coil (20).
An appliance (1) as in Claim 1 or 2, characterized in that the microcontroller (7) that provides the induction coil (20) to transmit power at a lower level than the minimum heating setting used in normal heating operations and at a higher frequency than the frequency in the minimum heating setting for operating the motor (5).
An appliance (1) as in any one of the above claims, characterized in that the resonant capacitor (9), the capacitance (C) of which is selected such that the frequency formed by the receiver coil (3) and the resonant capacitor (9) overlaps with the high frequency formed by the induction coil (20) at low power scales that do not heat the cooking pot (4).
An appliance (1) as in any one of the above claims, characterized in that a motor speed setting switch (14) connected to the microcontroller (7) and providing the speed of the motor (5) to be changed.
An appliance (1) as in any one of the above claims, characterized in that the direct current (DC) type motor (5), a rectifier (12) that converts AC voltage generated by the receiver coil (3) to DC voltage and in that a motor feeding capacitor (13) disposed at the outlet of the rectifier (12) and stabilizing the DC voltage feeding the motor (5).
An appliance (1) as in any one of the above claims, characterized in that the rectifier (12) that is used commonly for the motor (5), the microcontroller (7) and the user interface (8).
An appliance (1) as in Claim 7, characterized in that a DC – DC converter (15) that converts the high level DC voltage at the outlet of the rectifier (12) to low level DC voltage required for the microcontroller (7) and the user interface (8).
An appliance (1) as in any one of the Claims 6 to 8, characterized in that a buffer capacitor (16) and a diode isolator (17) disposed prior to the DC – DC converter (15) and protecting the microcontroller (7) and the user interface (8) from voltage drops resulting from sudden current drawing of the motor (5).
An appliance (1) as in any one of the Claims 1 to 5, characterized in that the alternative current (AC) type motor (5).
An appliance (1) as in any one of the above claims, characterized in that a voltage measuring unit (18) disposed at the outlet of the receiver coil (3), connected to the microcontroller (7) and measuring the voltage generated by the receiver coil (3).
An appliance (1) as in Claim 11, characterized in that the microcontroller (7) that provides the activation or deactivation of the resonant capacitor (9) depending on the voltage level desired to be decreased/increased, by actuating the switching element (10) according to the feedback from the voltage measuring unit (18).