JP5895224B2 - Induction heating rice cooker - Google Patents

Description

  The present invention relates to an induction heating rice cooker that induction-heats an object to be heated using a heating coil, and more particularly to an induction heating rice cooker that heats and cooks an object to be heated in a desired state by controlling the output of the heating coil with high accuracy. It is about.

In recent induction heating rice cookers, a configuration is provided in which a plurality of heating coils are provided around a pan to control the heating temperature and heating time of each heating coil, the heating schedule, and the like. In order to perform such control, it is necessary to detect the input power from the commercial power source and perform appropriate cooking to meet the conditions set by the user based on the detected input power. There is.
In a conventional induction heating rice cooker, CT is used as an input current detection means for detecting an alternating current input from a commercial power source to a rectifier circuit, and the alternating current signal detected by the CT is a rectifier circuit, an electrolytic capacitor, It is converted into a DC signal by a rectifying / smoothing circuit composed of a resistor or the like. The DC signal thus converted is used for drive control of an inverter circuit that drives a heating coil as a signal indicating an input current from a commercial power supply (see, for example, Patent Documents 1, 2, and 3).

Japanese Patent No. 4023438 Japanese Patent No. 4023439 Japanese Patent No. 4613736

As described above, in the conventional induction heating rice cooker, since heating control is performed based on the detection signal indicating the input current from the commercial power supply, it is an important issue to detect the input current with high accuracy. .
In addition, in a conventional induction heating rice cooker, an alternating current from a commercial power source is detected using CT before the input to the rectifying circuit, and the alternating current signal from the CT is composed of a rectifying circuit, an electrolytic capacitor, a resistor, and the like. The rectifying / smoothing circuit thus converted into a DC signal. The output voltage of the DC signal detected and converted in this way does not have a linear proportional relationship with the input current from the commercial power supply, and the output voltage increases as the input current increases. It has a curvilinear relationship in which the rate gradually decreases. This is because the output of the current transformer becomes saturated as the current flows. For this reason, in order to perform heating control of the heating coil based on the detected output voltage, it is necessary to calibrate and use the detected output voltage.

Furthermore, in the conventional induction heating rice cooker, since CT is used as a detector of an input electric current detection means, the circuit structure became large and it became the structure which has a heavy article. Therefore, the use of CT as the input current detection means has not been a preferable component in recent miniaturization, light weight, and cost reduction.
Further, in order to improve the accuracy of the output value of the current detection means, it has been necessary to adjust after detection using a variable resistor or the like.

  Thus, the present invention provides an induction heating rice cooker having a configuration capable of detecting the state of the input power source in the induction heating rice cooker with high accuracy and having a configuration capable of realizing a small size, light weight and low cost. The purpose is to provide.

The induction heating rice cooker according to the first aspect of the present invention comprises:
AC power supply that outputs AC power,
A driving power source having a rectifying circuit for rectifying the AC power of the AC power source and a low-pass filter circuit having a coil and a capacitor, and having a low potential side line and a high potential side line;
A rectifying / smoothing circuit for rectifying and smoothing the AC power of the AC power source to form a control power source;
A heating coil that is supplied with electric power from the drive power source and induction-heats an object to be heated;
An inverter circuit for controlling electric power from the drive power supply to the heating coil;
A drive unit that drives and controls the inverter circuit;
A current detector configured to detect a current flowing through the low-potential side line, and to drive the drive unit based on an output signal of the current detector; An induction heating rice cooker comprising a control unit for controlling,
A low potential side in the rectifying and smoothing circuit is connected to a low potential side of the resistor connected to the low potential side line , and a current value detected by the current detection unit is changed from the drive power source to the heating coil. and it is configured to be able to exclude the current flowing through the current value supplied to the inverter circuit shown controlled rectifier smoothing circuit. The induction heating rice cooker of the 1st aspect comprised in this way can provide the circuit structure which can detect the state of an input power supply with high precision, and can implement | achieve small size, light weight, and cost reduction. Become.

  In the induction heating rice cooker according to the second aspect of the present invention, in the current detection unit and the rectifying / smoothing circuit according to the first aspect, at least a part of a circuit forming a control power supply is on the first substrate. The first substrate is modularized and mounted on a second substrate having an inverter circuit component. The induction heating rice cooker of the 2nd aspect comprised in this way can implement | achieve small size, light weight, and cost reduction.

  In the induction heating rice cooker according to the third aspect of the present invention, the current detection unit according to the first aspect is based on the resistor connected to the low potential side line and the voltage across the resistor. And an amplifier that amplifies the detection current. The induction heating rice cooker of the 3rd aspect comprised in this way can provide the circuit structure which can detect the state of input power supply with high precision.

  In the induction heating rice cooker according to the fourth aspect of the present invention, the control unit in the first aspect is configured to detect current when the inverter circuit is in an OFF state based on a current detection signal from the current detection unit. Using the signal as a reference signal, the input current of the induction heating rice cooker is detected as a relative value. The induction heating rice cooker of the 4th aspect comprised in this way can provide the circuit structure which can detect the state of an input power supply with high precision in the structure which does not require offset adjustment.

An induction heating rice cooker according to a fifth aspect of the present invention is a first DC power supply circuit that receives the output from the rectifying / smoothing circuit in the second aspect and forms a first control power supply; A second DC power supply circuit that receives the output from the first DC power supply circuit and forms a second control power supply. The second control power supply has a voltage lower than that of the first control power supply. The second DC power supply circuit is integrated and adjusted with the current detection unit, and is modularized. The induction heating rice cooker of the 5th aspect comprised in this way can provide the circuit structure which can detect the state of an input power supply with high precision, and can implement | achieve small size, light weight, and cost reduction. Become.

According to the present invention, the current value detected by the current detector indicates the current value supplied from the drive power source to the heating coil and the inverter circuit, and the current flowing through the control rectifying and smoothing circuit can be excluded . It is possible to detect the state of the input power source with high accuracy and appropriately control the driving of the heating coil, and it is possible to provide an induction heating rice cooker that realizes small size, light weight, and low cost.

The circuit diagram which makes the circuit configuration of the induction heating rice cooker of Embodiment 1 which concerns on this invention partially block-ized, and shows it The circuit diagram which makes the circuit structure of the induction heating rice cooker of Embodiment 2 which concerns on this invention partially block-ized, and shows it The circuit diagram which makes the circuit structure of the induction heating rice cooker of Embodiment 3 which concerns on this invention partially block-ized, and shows it

  Hereinafter, although it demonstrates using an induction heating rice cooker as suitable embodiment which concerns on this invention, this invention is not limited to the structure of the induction heating rice cooker specifically described in the following embodiment. Rather, the present invention is applied to an induction heating cooker or induction heating apparatus configured based on the technical idea similar to the technical idea described in the embodiment and the technical common sense in this technical field.

Embodiment 1
FIG. 1 is a circuit diagram showing a circuit configuration of the induction heating rice cooker according to the first embodiment of the present invention, which is partially shown as a block.
In the induction heating rice cooker shown in FIG. 1, a heating coil 7 is provided in a storage unit for storing the pot 20 in proximity to a surface facing the bottom surface of the pot 20. The pan 20 accommodated in the induction heating rice cooker is configured to be induction-heated by being magnetically coupled to the heating coil 7 that is excited by being supplied with high-frequency power.

  An inverter circuit 10 for supplying high-frequency power to the heating coil 7 includes a resonance capacitor 8 and a switching unit 9. The resonance capacitor 8 is connected in parallel to the heating coil 7 and constitutes a resonance circuit together with the heating coil 7. As the resonance capacitor 8 in the first embodiment, a polypropylene capacitor having a small loss even when a high-frequency current flows is used. The switching unit 9 includes a semiconductor element such as a MOSFET or an IGBT that can perform a high-frequency switching operation, and a reverse connection diode connected in antiparallel to the semiconductor element. MOSFETs and IGBTs used as semiconductor elements have a high withstand voltage, and can flow a large current by applying a predetermined voltage to the gate terminal, and can flow a large current with less power than a power transistor. It has the characteristic.

  An AC power source 1 that is a commercial power source is connected to a rectifier circuit 2 that is a diode bridge, and supplies AC power to the rectifier circuit 2. The drive power source 25 performs full-wave rectification of the alternating current from the alternating current power source 1 and supplies power to the heating coil 7 via the inverter circuit 10. The drive power supply 25 is composed of a rectifier circuit 2 and a low-pass filter circuit, and the low-pass filter circuit includes a choke coil 3 and a capacitor 4.

  A zero voltage synchronization signal output circuit 14 is provided on a line through which AC power is supplied from the AC power source 1 to the drive power source 25. The zero voltage synchronization signal output circuit 14 detects the zero voltage of the AC power supplied from the AC power supply 1 and outputs a pulse signal corresponding to the detected zero voltage. The zero voltage synchronization signal output circuit 14 is configured to divide an alternating voltage input to the rectifier circuit 2 that is a diode bridge and input the divided voltage to the base terminal of the transistor. When the input voltage passes through the zero voltage, the transistor Is configured to turn on and off.

  In addition, a control rectifying and smoothing circuit 6 is provided in a line in which AC power is supplied from the AC power source 1 to the drive power source 25. The control rectifying / smoothing circuit 6 performs half-wave rectification on the AC power of the AC power supply 1 to convert it into DC power, and outputs the first signal having the first output voltage to the first DC power supply circuit 21. Supply. Furthermore, the first signal having the first output voltage (for example, 20V) output from the first DC power supply circuit 21 is input to the second DC power supply circuit 24, and the second output voltage (for example, A second signal having 5V) is output. The first signal output from the first DC power supply circuit 21 is a power supply signal for supplying power to a control unit (described later) 13 constituted by a microcomputer. The second signal output from the second DC power supply circuit 24 is a power supply signal for supplying power to a drive unit (described later) 11 for driving and controlling the inverter circuit 10.

  A drive signal from the drive unit 11 is input to the gate terminal of the switching element of the switching unit 9 in the inverter circuit 10 to drive the on / off operation of the switching element. The drive unit 11 includes an NPN transistor and a PNP transistor, and is configured by a push-pull circuit. The drive unit 11 is controlled by a control signal from the control unit 13.

  The trigger signal generation circuit 12 connected to both ends of the heating coil 7 is composed of a comparator or the like, and a first voltage formed by dividing one terminal by a resistance at a predetermined ratio, and the other terminal Is compared with a second voltage formed by resistance-dividing at a predetermined ratio, and a trigger signal corresponding to the comparison result is output to the control unit 13.

  The control unit 13 includes a microcomputer, and includes a current setting unit 15, an on-time setting unit 16, and a pulse generation unit 17. The control unit 13 is driven and controlled based on a command from the operation unit 18, and is configured such that the command content from the operation unit 18 and the control content from the control unit 13 are displayed on the display unit 19.

  The current setting unit 15 in the control unit 13 sets a target value of the input current supplied from the AC power supply 1, and is configured by a ROM or the like in the microcomputer. In Embodiment 1, a plurality of target values are set, for example, a first current set value when cooking normal rice, a second current set value when cooking non-washed rice, The third current set value and the like are stored as 8-bit data in the ROM.

  The on-time setting unit 16 in the control unit 13 sets the on-time of the switching element of the switching unit 10 according to the input current. The on-time setting unit 16 includes a comparator, a resistor, a capacitor, and the like, and outputs a signal corresponding to the on-time of the switching element to the pulse generation unit 17.

  The pulse generation unit 17 in the control unit 13 includes a sawtooth waveform generation circuit and a comparison circuit. The sawtooth waveform generation circuit includes a charging circuit using a comparator and a capacitor, and forms a sawtooth waveform based on the trigger signal from the trigger signal generation circuit 12. The comparison circuit is composed of a comparator or the like, and compares the output voltage of the sawtooth waveform generation circuit with the output voltage of the on-time setting unit 16 to form a control signal for driving and controlling the drive unit 11. When the control signal from the pulse generation unit 17 is input and the control signal is high, the drive unit 11 turns on, for example, the IGBT that constitutes the switching unit 9.

  In the induction heating rice cooker of the first embodiment, the input current is configured to be detected by the current detection unit 26 connected to the subsequent stage of the rectifier circuit 2. The current detection unit 26 includes a resistor, a current detection resistor 22 that is a so-called shunt resistor, and an amplifier 23. The current detection resistor 22 is connected so as to be included in the low potential side line in the output from the rectifier circuit 2, and a voltage proportional to the current flowing through the current detection resistor 22 is detected as a voltage across the current detection resistor 22. In the current detection unit 26, the amplifier 23 amplifies the voltage across the current detection resistor 22 to a predetermined ratio, and the amplified current is input to the on-time setting unit 16 of the control unit 13 as a current detection signal. The on-time setting unit 16 sets the on-time of the switching element of the switching unit 9 according to the input current indicated by the input current detection signal.

  In the induction heating rice cooker of the first embodiment, the control rectifying / smoothing circuit 6 for forming the first output voltage and the second output voltage is a half-wave rectifying / smoothing composed of a resistor, a rectifier circuit, and an electrolytic capacitor. Circuit. A DC signal is formed by this half-wave rectifying and smoothing circuit. In the configuration of the first embodiment, as shown in FIG. 1, the ground side of the electrolytic capacitor in the control rectifying and smoothing circuit 6 is connected to the low potential side line of the secondary side (output side) terminal of the drive power supply 25. . If further added, it is connected to the low potential side of the current detection resistor 22. Thus, since the low potential side line of the secondary side (output side) terminal of the drive power supply 25 is grounded, in the current detector 26 connected to the low potential side line, only the current flowing through the heating coil 7 is obtained. Can be detected, and the current flowing through the control rectifying and smoothing circuit 6 can be excluded.

  In the induction heating rice cooker of Embodiment 1, based on the current detection signal input from the current detection unit, the control unit 13 uses the current detection signal when the inverter circuit 10 is in the off state as a reference signal (voltage signal). It can comprise so that the input current of the said induction heating rice cooker may be detected as a relative value. With this configuration, the offset adjustment is unnecessary.

  Moreover, in the induction heating rice cooker of Embodiment 1, the current detection part 26 comprised by the current detection resistance 22 and the amplifier 23, and the 2nd DC power supply circuit 24 are modularized, and are integrated. It is composed of two devices (indicated by reference numeral 5 in FIG. 1). Thus, in the configuration of the first embodiment, the current detection unit 26 and the second DC power supply circuit 24 are modularized and incorporated in one device. For this reason, in the device having the functions of the current detection unit 26 and the second DC power supply circuit 24, specifications and characteristics are standardized and fixed by trimming processing. That is, a device in which the current detection unit 26 and the second DC power supply circuit 24 are modularized is a device that shows the same characteristics that are unified with high accuracy. Therefore, in the induction heating rice cooker according to the first embodiment, it is possible to detect the input current with high accuracy without variation, and in the control rectifying and smoothing circuit 6, the stable output output from the second DC power supply circuit 24 is possible. A drive signal with high accuracy can be formed in the drive unit 11 and the control unit 13 by the power source.

<< Embodiment 2 >>
Hereinafter, the induction heating rice cooker of Embodiment 2 which concerns on this invention is demonstrated using attached FIG. FIG. 2 is a circuit diagram showing a circuit configuration of the induction heating rice cooker according to the second embodiment of the present invention, which is partially shown as a block.

In the induction heating rice cooker of the second embodiment, the difference from the configuration of the first embodiment described above is the configuration range included in the modularized device. Other configurations of the induction heating rice cooker of the second embodiment are the same as those of the first embodiment. Therefore, in Embodiment 2, the same code | symbol is attached | subjected to what has the same function and operation | movement as Embodiment 1, and those description uses the description in Embodiment 1. FIG.
In the induction heating rice cooker of the second embodiment, similarly to the induction heating rice cooker of the first embodiment, the inverter circuit 10 for supplying high frequency power to the heating coil 7 includes a resonance capacitor 8 and a switching unit 9. It is comprised. The resonance capacitor 8 is connected in parallel to the heating coil 7 and constitutes a resonance circuit together with the heating coil 7. The switching unit 9 includes a semiconductor element such as a MOSFET or an IGBT that can perform a high-frequency switching operation, and a reverse connection diode connected in antiparallel to the semiconductor element. The switching unit 9 in the inverter circuit 10 is driven and controlled by a drive signal from the drive unit 11.

  Moreover, in the induction heating rice cooker of Embodiment 2, the AC power source 1 that supplies AC power to the induction heating rice cooker is connected to the drive power source 25, and the drive power source 25 is an AC current from the AC power source 1. Is supplied to the heating coil 7 via the inverter circuit 10. A zero voltage synchronization signal output circuit 14 is provided on a line through which AC power is supplied from the AC power source 1 to the drive power source 25. In addition, a control rectifying and smoothing circuit 6 is provided in a line in which AC power is supplied from the AC power source 1 to the drive power source 25. The control rectifying / smoothing circuit 6 performs half-wave rectification on the AC power of the AC power supply 1 to convert it into DC power, and outputs the first signal having the first output voltage to the first DC power supply circuit 21. Supply. Further, the first signal having the first output voltage (for example, 20V) output from the first DC power supply circuit 21 is input to the second DC power circuit 24 and the second output voltage (for example, for example). A second signal having 5V) is output. The first signal output from the first DC power supply circuit 21 is, for example, a power supply signal for supplying power to the control unit 13 configured with a microcomputer. The second signal output from the second DC power supply circuit 24 becomes, for example, a power supply signal for supplying power to the drive unit 11 for driving and controlling the inverter circuit 10.

  Moreover, in the induction heating rice cooker of Embodiment 2, the trigger signal generation circuit 12, the control part 13, the operation part 18, and the display part 19 are provided similarly to the induction heating rice cooker of Embodiment 1. .

  In the induction heating rice cooker of the second embodiment, the input current is detected by the current detection unit 26 connected to the subsequent stage of the rectifier circuit 2, and the current detection unit 26 is configured by the current detection resistor 22 and the amplifier 23. . The current detection resistor 22 is connected so as to be included in the low potential side line in the output from the rectifier circuit 2, and the voltage across the current detection resistor 22 is detected. In the current detection unit 26, the voltage across the current detection resistor 22 is amplified and input to the on-time setting unit 16 of the control unit 13 as a current detection signal.

  In the induction heating rice cooker of the second embodiment, the control rectifying / smoothing circuit 6 for forming the first output voltage and the second output voltage is a half-wave rectifying / smoothing composed of a resistor, a rectifying circuit, and an electrolytic capacitor. Circuit, and a direct current signal is formed. In the configuration of the second embodiment, as shown in FIG. 2, the ground side of the electrolytic capacitor in the control rectifying and smoothing circuit 6 is connected to the low potential side line of the secondary side (output side) terminal of the drive power supply 25. Thus, since the low potential side line of the secondary side (output side) terminal of the drive power supply 25 is grounded, in the current detector 26 connected to the low potential side line, only the current flowing through the heating coil 7 is obtained. Can be detected, and the current flowing through the control rectifying and smoothing circuit 6 is excluded.

  In the induction heating rice cooker of the second embodiment, the current detection unit 26 including the current detection resistor 22 and the amplifier 23, the first DC power supply circuit 21, and the second DC power supply circuit 24 are modularized and integrated. And one device (indicated by reference numeral 5A in FIG. 2). As described above, in the configuration of the second embodiment, the current detection unit 26, the first DC power supply circuit 21, and the second DC power supply circuit 24 are modularized and incorporated in one device. For this reason, in the device having the functions of the current detection unit 26, the first DC power supply circuit 21, and the second DC power supply circuit 24, the specifications and characteristics are standardized and fixed by trimming processing. That is, a device in which the current detection unit 26, the first DC power supply circuit 21, and the second DC power supply circuit 24 are modularized is a device that shows the same characteristics that are unified with high accuracy. Therefore, in the induction heating rice cooker of the second embodiment, it is possible to detect the input current with high accuracy without variation, and the DC power source formed in the control rectifying and smoothing circuit 6 is used as the first DC power source circuit 21. Since the power is supplied and then supplied to the second DC power supply circuit 24, a highly accurate control signal and drive signal can be formed by each stable power supply.

<< Embodiment 3 >>
Hereinafter, the induction heating rice cooker of Embodiment 3 which concerns on this invention is demonstrated using attached FIG. FIG. 3 is a circuit diagram showing a circuit configuration of the induction heating rice cooker according to the third embodiment of the present invention, which is partially shown as a block.

  In the induction heating rice cooker of the third embodiment, the difference from the configuration of the first embodiment is that a plurality of heating coils are provided, and a drive circuit for driving and controlling each heating coil is provided individually. Each drive circuit is configured to be switched. Other configurations of the induction heating rice cooker of the third embodiment are the same as those of the first embodiment. Therefore, in Embodiment 3, the same code | symbol is attached | subjected to what has the same function and operation | movement as Embodiment 1, and those description uses the description in Embodiment 1. FIG.

  In the induction heating rice cooker of the third embodiment, the first heating coil 7A for induction heating the lid 28 which is the object to be heated, and the second for induction heating the pan 20 which is the object to be heated similarly. Heating coil 7B. The first heating coil 7A is configured to be supplied with high frequency power by the first inverter circuit 10A, and the second heating coil 7B is configured to be supplied with high frequency power from the second inverter circuit 10B. Has been. Each inverter circuit 10A, 10B has resonance capacitors 8A, 8B and switching units 9A, 9B, respectively. The first resonance capacitor 8A is connected in parallel to the first heating coil 7A, and constitutes a resonance circuit together with the first heating coil 7A. Similarly, the second resonance capacitor 8B is connected in parallel to the second heating coil 7B, and constitutes a resonance circuit together with the second heating coil 7B. Each of the switching units 9A and 9B is configured by a semiconductor element such as a MOSFET or IGBT capable of performing a high-frequency switching operation, and a reverse connection diode connected in antiparallel to the semiconductor element.

  In the induction heating rice cooker of the third embodiment, the switching unit 9A in the first inverter circuit 10A is driven by a drive signal from the first drive unit 11A. The switching unit 9B in the second inverter circuit 10B is driven by a drive signal from the first drive unit 11B. The first driving unit 11A and the second driving unit 11B are configured such that the driving state is switched by a switching circuit 27 to which a switching signal from the control unit 13 is input.

  In the induction heating rice cooker of the third embodiment, the input current is detected by the current detection unit 26 connected to the subsequent stage of the rectifier circuit 2, and the current detection unit 26 is configured by the current detection resistor 22 and the amplifier 23. . The current detection resistor 22 is connected so as to be included in the low potential side line in the output from the rectifier circuit 2, and the voltage across the current detection resistor 22 is detected. In the current detection unit 26, the voltage across the current detection resistor 22 is amplified and input to the on-time setting unit 16 of the control unit 13 as a current detection signal.

  In the induction heating rice cooker according to the third embodiment, the current detection unit 26 including the current detection resistor 22 and the amplifier 23 is modularized and integrated to form a single device. Thus, in the configuration of the third embodiment, the current detection unit 26 is modularized and incorporated in one device. For this reason, in the current detection unit 26, specifications and characteristics are standardized and fixed by trimming processing. Therefore, in the induction heating rice cooker according to the third embodiment, it is possible to detect the input current with high accuracy without variation.

  Since this invention is a structure which can detect an input current with high precision in the induction heating rice cooker which induction-heats a to-be-heated object using a heating coil, it can provide a highly reliable induction heating rice cooker. It is highly versatile.

DESCRIPTION OF SYMBOLS 1 AC power supply 2 Rectification circuit 3 Choke coil 4 Smoothing capacitor 5 Modular device 6 Control rectification smoothing circuit 7, 7A, 7B Heating coil 8, 8A, 8B Resonance capacitor 9, 9A, 9B Switching unit 10, 10A , 10B Inverter circuit 11, 11A, 11B Drive unit 12 Trigger signal generation circuit 13 Control unit 14 Zero voltage synchronization signal output circuit 15 Current setting unit 16 On-time setting unit 17 Pulse generation unit 18 Operation unit 19 Display unit 20 Pan 21 First DC power supply circuit 22 Current detection resistor 23 Amplifier 24 Second DC power supply circuit 25 Drive power supply 26 Current detection unit 27 Switching circuit 28 Lid

Claims (5)

AC power supply that outputs AC power,
A driving power source having a rectifying circuit for rectifying the AC power of the AC power source and a low-pass filter circuit having a coil and a capacitor, and having a low potential side line and a high potential side line;
A rectifying / smoothing circuit for rectifying and smoothing the AC power of the AC power source to form a control power source;
A heating coil that is supplied with electric power from the drive power source and induction-heats an object to be heated;
An inverter circuit for controlling electric power from the drive power supply to the heating coil;
A drive unit that drives and controls the inverter circuit;
A current detector configured to detect a current flowing through the low-potential side line, and to drive the drive unit based on an output signal of the current detector; An induction heating rice cooker comprising a control unit for controlling,
A low potential side in the rectifying and smoothing circuit is connected to a low potential side of the resistor connected to the low potential side line , and a current value detected by the current detection unit is changed from the drive power source to the heating coil. An induction heating rice cooker configured to indicate a current value supplied to the inverter circuit.
  In the current detection unit and the rectifying / smoothing circuit, at least a part of a circuit forming a control power supply is mounted and adjusted on a first substrate, and the first substrate is modularized to include an inverter circuit component. The induction heating rice cooker according to claim 1, wherein the induction heating rice cooker is mounted on the substrate of 2.   2. The induction according to claim 1, wherein the current detection unit includes the resistor connected to the low potential side line, and an amplifier that amplifies a detection current based on a voltage across the resistor. Heated rice cooker.   The control unit is configured to detect an input current of the induction heating rice cooker as a relative value based on a current detection signal from the current detection unit, using a current detection signal in an off state in the inverter circuit as a reference signal. The induction heating rice cooker according to claim 1. An output from the rectifying and smoothing circuit is input to form a first DC power supply circuit that forms a first control power supply, and an output from the first DC power supply circuit is input to form a second control power supply. A second DC power supply circuit, wherein the second control power supply has a voltage lower than that of the first control power supply, and the second DC power supply circuit is integrated and adjusted with the current detection unit, The induction heating rice cooker according to claim 2 configured as a module.

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