JPH11260540A - Induction heating cooking device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electromagnetic induction heating cooking device capa ble of saving electric power during standby. SOLUTION: This cooking device is provided with a high frequency electric power source 3 for supplying high frequency electric current to a heating coil 4 while using a commercial a.c. power source 1 as input, a relay 2 for disconnecting the high frequency electric power source 3 and the commercial a.c. power source 1, and an electronic control circuit 6 for controlling the starting and the stopping of heating by the high frequency electric power source 3 and the opening and the closing of the relay 2.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to an induction heating cooker.

[0002]

2. Description of the Related Art FIG. 9 is a block diagram showing the configuration of a conventional general induction heating cooker, and FIG. 10 shows a specific configuration example of an operation unit.

In FIG. 9, reference numeral 1 denotes a commercial AC power supply, and 2 denotes a power switch for turning on / off the commercial AC power. As the power switch 2, a switch of a type that mechanically disconnects a contact so that a user turns on / off the commercial AC power supply 1 is used, and the power switch is exposed from an opening provided in the investigation unit. Configuration is common.

[0004] Reference numeral 3 denotes a high-frequency power supply for converting the commercial AC power supply 1 into DC and generating a high-frequency power supply. Reference numeral 4 denotes a heating coil that performs induction heating using a high-frequency current supplied from a high-frequency power supply. This heating operation is controlled by an electronic control circuit 6 including a microcomputer operated by a first DC power supply 5 that supplies a DC voltage of about 5 V. Reference numeral 7 denotes a second DC power supply for supplying a 22V DC voltage for driving a fan motor 8 for cooling the high frequency power supply 3 and the like.

Hereinafter, a specific operation will be described with reference to an operation unit shown in FIG. In order to use this induction heating cooker, first, the power switch 2 is turned on, and then the heating on / off key 9 constituting the electronic control circuit is operated. Reference numeral 4 denotes an apparatus for starting induction heating and heating the pot of the load, and the amount of heating is adjusted by an up / down key 11 constituting the electronic control circuit 6. The result of the adjustment is displayed on the display lamp 10. At this time, if the power switch 2 is kept on, the high frequency power supply 3, the first DC power supply 5,
The electronic control circuit 6, the second DC power supply 7, and the like consume power of several W even in a standby state where heating is not performed, so that the power switch 2 is turned off when the apparatus is not generally used. . Further, when the power switch 2 is operated to start energizing the induction heating cooker, when the smoothing capacitor constituting the high frequency power supply 3 is charged, the durability of the contact is prevented from being deteriorated due to the excessive rush current. Or a power switch with a performance that can withstand an excessive rush current with respect to the maximum rated current during induction heating.

The power switch 2 is connected to the power switch 2 shown in FIG.
(B) As shown in the BB 'cross section, the operation stroke is large, so that the operation cannot be performed from above the waterproof seal 12, so that the operation is performed from the opening formed in the waterproof seal 12. Alternatively, the opening and the power switch 2 are covered with a waterproof seal 12 made of a flexible material such as silicone resin.

On the other hand, the heating control /
Since the signals of the off key 9 and the up / down key 11 are controlled by the first DC power supply 5 of 5 V, it is only necessary to turn on / off a minute current, and a switch with a small stroke can be used. Therefore, a configuration in which the operation is performed from above the waterproof seal 12 is possible.

[0008]

However, in the induction heating cooker having the above-described structure, the first problem is that the power switch 2 operated by the user is exposed from the waterproof seal 12 so that the user operates the power switch 2. There was a problem that moisture such as cooked food spilled into the power switch 2 penetrated into the inside of the power switch 2, and the opening and all of the power switch 2 were sealed with a waterproof seal 12 made of a flexible material such as silicone resin. In order to cover the waterproof seal 12, it is expensive to prevent the waterproof seal 12 from being broken by repeated operation of the power switch 2 with a large operation stroke. For this reason, there has been a demand for an induction heating cooker having a power switch with an inexpensive structure that can be operated from above the waterproof seal 12 and having a low power consumption during standby without heating.

[0009] As a second problem, generally, in the induction heating cooker, a relatively large-capacity smoothing capacitor of about 6 μF is used as the configuration of the high-frequency power supply 3. Since the charging voltage of the smoothing capacitor is released at the time of opening, an arc discharge occurs between the contacts of the power switch when the power switch 2 is operated to stop energizing the induction heating cooker. An induction heating cooker that operates safely without the need for a protection circuit to prevent the deterioration of the durability of the contacts due to the above or without using an expensive power switch with excessive performance for the rated current is required. Has been requested.

The third problem is that the power switch 2
Is required to protect the smoothing capacitor 3a constituting the high-frequency power supply 3 when the induction heating cooker is turned on by operating the power supply to prevent the durability of the contact from being deteriorated due to the excessive inrush current. There is a demand for an induction heating cooker that does not require an expensive power switch 2 with no performance or an excessive performance for a rated current.

A fourth problem is that the power switch 2
Even if the user leaves the side of the induction heating cooker by forgetting to turn off the power, the user does not continue to consume large electric power, and the user mistakenly turns on the heat once with the power switch 2 forgotten to be turned off. There is a demand for a safe induction heating cooker that does not immediately start heating by operating the / off key 9.

As a fifth problem, there is a need for a safe induction heating cooker which cannot be used when an electronic control circuit or the like for controlling the induction heating cooker fails.

As a sixth problem, there is a need for a safe-to-use induction heating cooker that can be used immediately by a user to know the failure when an electronic control circuit or the like for controlling the induction heating cooker fails.

Further, as a seventh problem, there is a need for a safe-to-use induction heating cooker capable of self-determining and recovering from a failure in an electronic control circuit or the like for controlling the induction heating cooker in the event of a failure.

An eighth problem is that the electronic control circuit for controlling the induction heating cooker and the power supply circuit for driving the same can be used safely without unstable operation in a transient state of operation and always stable operation. There is a need for induction heating cookers.

As a ninth problem, in a standby state in which heating is stopped, only a microcomputer for accepting a switch input for starting operation of the device, peripheral electronic circuits of the switch input, and a power supply circuit therefor are driven. Other power supply circuits for driving the fan motor do not need to be operated, and the power consumption continues to increase even though it is not necessary.This induction heating reduces the power consumption in the standby state of the equipment. There is a need for cookers.

A tenth object is to provide a safe-to-use induction heating cooker in which an input signal to an electronic control circuit for controlling the induction heating cooker is always performed while the electronic control circuit is operating stably. Have been.

[0018]

SUMMARY OF THE INVENTION In order to solve the first problem, the present invention provides a relay for disconnecting a high-frequency power supply from a commercial AC power supply, starting and stopping of heating by the high-frequency power supply, and opening and closing of the relay. An electronic control circuit for instructing start and stop of the short circuit and the heating is provided.

In order to solve the above-mentioned second problem, the present invention relates to a method of opening a relay in response to an instruction from an electronic control circuit during a period from a voltage peak point of a commercial AC power supply to a voltage zero point and at a predetermined voltage or less. It is.

[0020] In order to solve the third problem, the present invention is directed to a method for short-circuiting a relay according to an instruction from an electronic control circuit during a period from a voltage peak point of a commercial AC power supply to a zero voltage point and at a predetermined voltage or less. It is.

According to another aspect of the present invention, in order to solve the fourth problem, when the heating is not started within a predetermined time when the relay is short-circuited, the relay is opened by an instruction of the electronic control circuit. Things.

In order to solve the above-mentioned fifth problem, the present invention provides a power supply detecting means for detecting the opening and closing of a relay, wherein the instruction to the relay by the electronic control circuit does not match the measurement result by the power supply detecting means. Is to stop the operation of the high frequency power supply.

Further, in order to solve the sixth problem, the present invention provides a predetermined notification when heating is stopped based on the measurement result of the power supply detecting means.

In order to solve the above-mentioned seventh problem, the present invention provides an electronic control circuit for opening and shorting a relay when an instruction to the relay by the electronic control circuit and a measurement result by the power supply detecting means do not match. Is repeated a predetermined number of times at predetermined time intervals, or until the instruction to the relay by the electronic control circuit and the measurement result by the power supply detection unit match.

Further, in order to solve the eighth problem, the present invention is to start heating by a heating coil and a high-frequency power supply after waiting for a predetermined time from a relay short-circuit instruction by an electronic control circuit.

In order to solve the ninth problem, the present invention provides an electronic circuit constituting an electronic control circuit, a first DC power supply for operating a microcomputer and the like, and a signal for monitoring the operation of a high-frequency power supply. A second DC power supply for driving an integrated circuit such as a comparator for taking in the electronic control circuit is provided, and the second DC power supply is stopped while the relay is open.

Further, in order to solve the tenth problem, the present invention provides that the relay is short-circuited after waiting for a predetermined time from the start of the operation of the second DC power source, and the operation of the second DC power source is stopped after the standby of the relay. This is performed after waiting for a predetermined time from opening.

[0028]

DETAILED DESCRIPTION OF THE INVENTION According to the first aspect of the present invention, a heating coil, a high-frequency power supply for generating a high-frequency current from a commercial AC power supply and supplying a high-frequency current to the heating coil, and a disconnection between the high-frequency power supply and the commercial AC power supply. It is composed of a relay, an electronic control circuit for instructing start and stop of heating by a high-frequency power supply, and opening and shorting of the relay, so that only a switch with a small stroke that can be operated with a small current is used for the electronic control circuit. This prevents the intrusion of moisture into the operation section of the electronic control circuit and reduces the standby power consumed by the high-frequency power supply.

According to a second aspect of the present invention, in the induction heating cooker according to the first aspect, the relay is opened by an instruction of the electronic control circuit during a period from a voltage peak point of the commercial AC power supply to a zero voltage point and at a predetermined voltage. The operation is performed as follows, thereby obtaining an effect of reducing arc discharge when the relay contact is opened.

According to a third aspect of the present invention, in the induction heating cooker according to the first aspect, the relay is short-circuited by an instruction from the electronic control circuit during a period from a voltage peak point of the commercial AC power supply to a zero voltage point and at a predetermined voltage. This is performed as described below, thereby obtaining an effect of reducing the rush current to the contacts when the relay contacts are short-circuited.

According to a fourth aspect of the present invention, in the induction heating cooker according to the first aspect, when the heating is not started within a predetermined time when the relay is short-circuited, the relay is opened by an instruction of the electronic control circuit. Thus, even if the user forgets to turn off the power switch, the high frequency power supply is automatically disconnected from the commercial AC power supply.

According to a fifth aspect of the present invention, in the induction heating cooker of the first aspect, a power supply detecting means for detecting opening and closing of the relay is provided, and an instruction to the relay by the electronic control circuit and a measurement result by the power supply detecting means are provided. If they do not match, the operation of the high-frequency power supply is stopped, so that if the relay has any failure, the operation cannot be performed.

According to a sixth aspect of the present invention, in the induction heating cooker according to the fifth aspect, when the heating is stopped based on the measurement result of the power supply detecting means, a predetermined notification is made, whereby the relay is operated. In the event of a failure, an effect of informing the user of the failure is obtained.

According to a seventh aspect of the present invention, in the induction heating cooker according to the fifth aspect, when the instruction to the relay by the electronic control circuit does not match the measurement result by the power supply detecting means, the electronic control circuit operates the relay. The instruction of opening and shorting is performed a predetermined number of times at a predetermined time interval, or is repeatedly performed until the instruction to the relay by the electronic control circuit and the measurement result by the power detection unit match, whereby the relay has a contact welding failure, or In the case of a malfunction due to failure of contact short-circuit, the relay drive signal is output again.

According to an eighth aspect of the present invention, in the induction heating cooker according to the first aspect, the induction heating by the heating coil and the high frequency power supply is started after a lapse of a predetermined time from an instruction to short-circuit the relay by the electronic control circuit. In an unstable state in which the contact of the relay is bound immediately after the relay contact is short-circuited and the contact is repeatedly opened and short-circuited in a short time, the effect is obtained that heating is not started.

According to a ninth aspect of the present invention, in the induction heating cooker according to the first aspect, the operation of an electronic circuit constituting an electronic control circuit, a first DC power supply for operating a microcomputer and the like, and the operation of a high-frequency power supply are monitored. A second DC power supply for driving an integrated circuit such as a comparator for taking in a signal to be supplied to the microcomputer, and stopping the operation of the second DC power supply while the relay is open, thereby waiting for the equipment. In the state, the operation of eliminating the power consumed by the second DC power supply is obtained.

According to a tenth aspect of the present invention, in the induction heating cooker according to the ninth aspect, the relay is short-circuited after waiting for a predetermined time from the start of the operation of the second DC power supply, and the operation of the second DC power supply is stopped. Is performed after waiting for a predetermined time from the opening of the relay, so that the input of a signal for monitoring the operation of the high-frequency power supply to an integrated circuit such as a comparator is always performed while the integrated circuit is operating stably. It is.

[0038]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS (Embodiment 1) Hereinafter, an embodiment will be described with reference to the drawings.

In FIG. 1, 1 is a commercial AC power source, 2
Is a relay for connecting the commercial AC power supply 1 to the high frequency power supply 3. The high-frequency power supply 3 supplies high-frequency current to the heating coil 4 to perform induction heating. Reference numeral 5 denotes a first DC power supply for extracting a 5V DC voltage from the commercial AC power supply 1, and supplies power to an electronic control circuit 6 including a microcomputer, peripheral electronic circuits, and switches operated by a user. ing.

Reference numeral 7 denotes a second DC power supply for extracting a DC voltage of 22 V from the commercial AC power supply 1. The integrated circuit such as a comparator for taking the operation of the high-frequency power supply into the electronic control circuit 6 and the high-frequency power supply 3 are cooled. Power for driving the fan motor 8 is supplied.

FIG. 2 shows the operation section of the induction heating cooker. 9 is a heating on / off key for starting heating.
Reference numeral 10 denotes an indicator lamp indicating the heating power of the heating. The adjustment of the heating power is performed by the up / down key 11 as in the conventional example.
Reference numeral 13 denotes a power key. Since the power key 13 only needs to turn on / off a signal that uses the output of the first DC power supply 5 of 5 V as a power source, a switch with a small operation stroke and a small current is used. The operation is performed from above the waterproof seal 12, as shown in the AA 'section of FIG. 2B.

Here, when the user operates the power key 13, the power lamp 16 is turned on to indicate that the energization is started, the opened relay 2 is short-circuited, and the high-frequency power supply 3 is connected to the commercial AC power supply. Is what is done. When the user operates the heating on / off key 9 in this state, the high frequency power supply 3 starts supplying a high frequency current to the heating coil 4 by a signal from the electronic control circuit 6 to perform induction heating.

(Embodiment 2) FIG. 3 is a timing chart showing the operation of the second embodiment of the present invention. In FIG. 3, when the user operates the power key 13 in a state where the induction heating cooker is operating, the electronic control circuit 6 causes the relay 2 to be opened at a time Ta after a predetermined time has elapsed from the voltage zero point of the commercial AC power supply 1. Output a signal. The contact of the relay 2 is opened at a time Tb after a specific operation delay time Tc based on the electrical characteristics of the relay 2 from the time when the signal for opening the relay 2 is output. At this time, the time Ta is set so that the voltage of the commercial AC power supply 1 becomes 20 V or less.

(Embodiment 3) FIG. 4 is a timing chart showing the operation of the third embodiment of the present invention. In FIG. 4, when the user first operates the power supply key 13 in a state where the induction heating cooker is not operating, the electronic control circuit 6 causes the relay 2 to be short-circuited at a time Td after a predetermined time has elapsed from the zero voltage point of the commercial AC power supply. Output a signal. The contact of the relay 2 is short-circuited at a time Tf after an inherent operation delay time Te due to the electrical characteristics of the relay 2 from the time when the relay 2 short-circuit signal is output. The voltage of the commercial AC power supply 1 at this time is 20 V
The time Td is set as follows.

(Embodiment 4) FIG. 5 is a timing chart showing the operation of the fourth embodiment of the present invention. In FIG. 5, when the user first operates the power key 13 in a state where the induction heating cooker is not operating, the electronic control circuit 6 outputs a signal indicating that the relay 2 is short-circuited.

In this state, if it is normal, the first embodiment will be described.
The heating is started by operating the heating ON / OFF key 9 as shown in FIG. 5, but if the user does not perform the heating operation for 30 seconds as shown in FIG. 5, the relay 2 is opened by the signal output of the electronic control circuit 6. Then, the induction heating cooker is returned to the standby state.

This operation is the same when the heating ON / OFF key 9 is operated during heating and no operation is performed for 30 seconds after the heating is stopped, and the relay 2 is opened and the apparatus is on standby. It returns to the state.

(Embodiment 5) FIG. 6 is a block diagram showing the configuration of a fifth embodiment of the present invention. A smoothing capacitor 3 is provided on the output side of a diode bridge 3a constituting the high-frequency power supply 3.
b are connected in parallel, the voltage between both ends of the smoothing capacitor 3b is divided, and the divided voltage is input to a comparator 14 operating as a power source (indicated as Vu in the figure) by a second DC power source 7 and compared with a reference voltage. doing. This voltage detection and the operation of the comparator 14 are the power supply detection means 15.

When the relay 2 is short-circuited, a DC voltage of about 141 is applied across the smoothing capacitor 3b as an output of the commercial AC power supply 1 after full-wave rectification of 100V AC.
V is output. At this time, the input obtained by dividing the reference voltage of the comparator 14 and the voltage across the smoothing capacitor 3b is
Even if the commercial AC power supply 1 is 80 V AC, the output of the comparator 14 is set to be High and input to the electronic control circuit 6. That is, the relay 2 is opened or 80
When the voltage is lower than V, the output of the comparator serving as the power supply detecting means 15 becomes Low.

FIG. 7 is a timing chart showing the operation of this embodiment of the present invention. In FIG. 7, the electronic control circuit 6
Is a comparison between the operation of the relay drive output and the operation of the output of the power supply detection means 15. If the operation of the relay 2 is normal,
An output signal of the power supply detecting means 15 delayed by a time constant for charging and discharging the smoothing capacitor 3b is input to the electronic control circuit 6.

On the other hand, if the relay 2 is kept open, a low signal is always input.
Since a High signal is always input, an abnormality of the relay 2 can be detected. As a result, in this embodiment, when an abnormality of the relay 2 is detected, the induction heating by the high-frequency power supply 3 and the heating coil 4 is prohibited.

In this embodiment, it is assumed that the relay 2 has failed.
Obviously, a failure or the like in which a is open can be detected.

(Embodiment 6) In the sixth embodiment of the present invention, when the abnormality of the relay 2 is detected in the fifth embodiment, the power supply lamp 16 shown in FIG. It is realized by blinking at.

(Embodiment 7) FIG. 8 is a timing chart showing the operation of the seventh embodiment of the present invention. Even if the drive signal of the relay 2 is output, if the signal of the contact short-circuit of the relay 2 does not return from the power detection means 15, the drive signal for turning on / off the relay 2 is repeatedly output at one second intervals. . Then, when the drive signal of the relay 2 contact short-circuit and the output of the power supply detecting means 15 match, it is determined that the relay 2 has returned to the normal operation, and the normal operation has been continued thereafter.

In this embodiment, the operation when the operation is returned to the normal operation is shown. However, even if the drive signal for turning on / off the relay 2 is repeated eight times at one second intervals, the drive signal for short-circuiting the relay 2 contact and the power supply If the outputs of the detecting means 15 do not match,
It is determined that the relay 2 is abnormal and the heating is prohibited.

Embodiment 8 An eighth embodiment of the present invention is shown in FIG.
This will be described with reference to FIG. As already shown in FIG.
The contact of the relay 2 has a specific time delay from the output of the drive signal for the short-circuit of the relay 2 from the electronic control circuit 6 to the short-circuit of the contact of the relay 2. Further, even after the contact is closed once, the contact may be short-circuited after the contact bounces and repeatedly opens and closes in a short time.

In this embodiment, this series of relays 2
In order to energize after the operation of contact short-circuit is completed, heating is started two times after passing the voltage zero point of the commercial AC power supply cycle after outputting the signal of contact short-circuit.

(Embodiment 9) A ninth embodiment of the present invention will be described with reference to FIG.
This will be described with reference to FIG. In this embodiment, after confirming that the relay 2 has been opened and waiting for a predetermined time, the voltage supply of the second DC power supply 7 is stopped, the operation of the comparator 14 is stopped, and the input of the reference voltage is also stopped. is there.

(Embodiment 10) A tenth embodiment of the present invention will be described with reference to FIG. In this embodiment, when the user operates the power key 13 to start the operation of the induction heating cooker, the operation of the electronic control circuit 6 first stops the second direct current. The operation of the power supply 7 is started, and after the voltage output is stabilized, the relay is short-circuited. Also, when the user presses the power key 1
When the operation of the induction heating cooker is stopped by operating the electronic control circuit 3, the contact of the relay 2 is first opened, and after waiting for a predetermined time until the operation of the contact is settled, the operation of the electronic control circuit 6 is started. Thus, the operation of the second DC power supply 7 is stopped.

[0060]

As described above, according to the first aspect of the present invention, a relay for disconnecting between a high-frequency power supply and a commercial AC power supply, starting and stopping of heating by the high-frequency power supply, and opening and shorting of the relay are instructed. With the provision of an electronic control circuit, only switches with a small stroke, which can be operated with a small current, can be used for the operation section of the electronic control circuit, and a configuration is provided to prevent moisture from entering the operation section of the electronic control circuit. However, it is possible to reduce the power consumed by the high-frequency power supply during standby of the device.

According to the second aspect of the present invention, the opening of the relay in accordance with the instruction of the electronic control circuit is performed during the period from the voltage peak point of the commercial AC power supply to the zero voltage point and at a predetermined voltage or less. The arc discharge at the time of opening the relay contact can be reduced, the durability of the contact can be improved, and the induction heating cooker can be used without causing a failure.

According to the third aspect of the present invention, the relay is short-circuited by the instruction of the electronic control circuit during the period from the voltage peak point of the commercial AC power supply to the voltage zero point and at a predetermined voltage or less. The inrush current to the contact when the contact is short-circuited can be reduced, the durability of the contact can be improved, and failure such as welding of the contact can be suppressed.

According to the fourth aspect of the present invention, when heating is not started within a predetermined time when the relay is short-circuited, the relay is opened by an instruction of the electronic control circuit, so that the user can operate the relay. Even if you forget to turn off the power switch, the high-frequency power supply can be automatically disconnected from the commercial AC power supply. The effect is obtained that a safe operation can be realized in which heating can be started immediately by one operation of the heating ON / OFF key.

According to the fifth aspect of the present invention, the power supply detecting means for detecting the opening and closing of the relay is provided, and when the instruction to the relay by the electronic control circuit does not match the measurement result by the power supply detecting means, the high frequency power supply is provided. By stopping the operation of the relay, it is possible to obtain an effect that it is possible to realize an induction heating cooker that can be used safely without a user being heated while the relay is broken in the event that the relay fails. it can.

Further, according to the invention of claim 6, in particular, when a failure or the like of the relay is detected according to the measurement result of the power supply detecting means and heating is stopped, a predetermined notification is made. When a relay or the like fails, the user can be notified of the failure, and the user can notice the failure of the device before starting cooking using the induction heating cooker.

According to the present invention, when the instruction to the relay by the electronic control circuit does not match the measurement result by the power supply detecting means, the instruction to open and short the relay is given by the electronic control circuit. A predetermined number of time intervals, or by performing until the instruction to the relay by the electronic control circuit and the measurement result by the power supply detection unit match, when the relay constituting the induction heating cooker of the present invention has a contact welding failure If the degree of welding of the relay is light, it can be expected that the welded contacts will be separated and the operation of the relay will return, or if a malfunction due to contact short circuit failure has occurred, the drive signal will be sent again to normal operation. The effect that operation can be expected is obtained. That is, in the induction heating cooker, since a relatively large-capacity capacitor is used for the high-frequency power supply, a large current is likely to flow at one time, such as when a relay contact is short-circuited compared to other devices, and therefore, the relay contact Although there is a great risk of welding or the like, according to the present invention, it is possible to appropriately control the opening and closing of the relay contact while maintaining the material and the like of the relay contact at the same level as other devices.

According to the present invention, the heating is performed particularly in an unstable state in which the contact of the relay is bound immediately after the relay contact is short-circuited and the contact is repeatedly opened and shorted in a short time. Since the relay contacts do not start, energization can be performed after the relay contacts are surely short-circuited, arc discharge or the like of the contacts of the relay can be prevented, and the effect of improving the durability of the relay contacts can be obtained.

Further, according to the ninth aspect of the present invention, the electronic circuit constituting the electronic control circuit, the first DC power supply for operating the microcomputer and the like, and a signal for monitoring the operation of the high frequency power supply are taken into the microcomputer. A second DC power supply for driving an integrated circuit such as a comparator for receiving a voltage supply from the second DC power supply by stopping the second DC power supply while the relay is open. Since the power consumed by the operating comparator and other circuits of the electronic control circuit is eliminated, the effect of reducing the power consumption in the standby state of the device can be obtained.

According to the tenth aspect of the present invention, the relay is short-circuited after waiting for a predetermined time from the start of the operation of the second DC power supply, and the operation of the second DC power supply is stopped for a predetermined time from the opening of the relay. By performing the operation after the standby, the input of the signal for monitoring the operation of the high-frequency power supply to the integrated circuit such as the comparator is always performed while the integrated circuit is operating stably, so that the power of the integrated circuit such as the comparator is supplied. This prevents the circuit from malfunctioning due to input only when the circuit is not operating.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a configuration of an induction heating cooker according to an embodiment of the present invention.

FIG. 2 is a diagram showing an operation unit of the induction heating cooker;

FIG. 3 is a timing chart showing the operation of the induction heating cooker according to the second embodiment of the present invention.

FIG. 4 is a timing chart showing the operation of the induction heating cooker according to the third embodiment of the present invention.

FIG. 5 is a timing chart showing the operation of the induction heating cooker according to the fourth embodiment of the present invention.

FIG. 6 is a block diagram showing a configuration of an induction heating cooker according to a fifth embodiment of the present invention.

FIG. 7 is a timing chart showing the operation of the induction cooking device.

FIG. 8 is a timing chart showing the operation of the induction heating cooker according to the eighth embodiment of the present invention.

FIG. 9 is a block diagram showing the configuration of a conventional induction heating cooker.

FIG. 10 is a diagram showing an operation unit of the induction heating cooker;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Commercial AC power supply 2 Power switch 3 High frequency power supply 3a Diode bridge 3b Smoothing capacitor 4 Heating coil 5 First DC power supply 6 Electronic control circuit 7 Second DC power supply 8 Fan motor 9 Heating on / off key 10 Display lamp 11 Up / down Key 12 Waterproof seal 13 Power key 14 Comparator 15 Power detection means 16 Power lamp

Claims (10)

[Claims] 1. A commercial AC power supply, a high-frequency power supply for supplying a high-frequency current to a heating coil with the commercial AC power supply as an input, a relay for disconnecting the high-frequency power supply from the commercial AC power supply, and heating by the high-frequency power supply An induction heating cooker comprising an electronic control circuit for controlling start and stop of the relay and opening and shorting of a relay. 2. The induction heating cooker according to claim 1, wherein the electronic control circuit opens the relay contact during a period from a voltage peak point of the commercial AC power supply to a voltage zero point and at a predetermined voltage or less. 3. The induction heating cooker according to claim 1, wherein the electronic control circuit short-circuits the relay contact during a period from a voltage peak point of the commercial AC power supply to a voltage zero point and at a predetermined voltage or less. 4. The induction heating cooker according to claim 1, wherein the electronic control circuit controls the relay contacts to be opened if heating is not started within a predetermined time during short-circuit control of the relay contacts. 5. A power supply detecting means for detecting opening and closing of a relay contact, wherein the operation of the high-frequency power supply is stopped when an instruction to the relay by the electronic control circuit does not match a measurement result by the power supply detecting means. Item 7. An induction heating cooker according to Item 1. 6. The induction heating cooker according to claim 5, wherein when the heating is stopped according to the measurement result of the power supply detecting means, the fact is notified. 7. When the instruction to the relay by the electronic control circuit and the measurement result by the power supply detecting means do not match, the electronic control circuit instructs to open and short the relay a predetermined number of times at a predetermined time interval, or 6. The induction heating cooker according to claim 5, wherein the operation is repeated until the instruction to the relay by the circuit and the measurement result by the power supply detection unit match. 8. The induction heating cooker according to claim 1, wherein the heating by the heating coil and the high-frequency power source is started after waiting for a predetermined time from the relay short-circuit instruction by the electronic control circuit. 9. An electronic circuit constituting an electronic control circuit, a first DC power supply for operating a microcomputer and the like,
A second driving of an integrated circuit such as a comparator for taking a signal for monitoring the operation of the high-frequency power supply into the electronic control circuit
2. The induction heating cooker according to claim 1, wherein the DC power supply is provided and the second DC power supply is stopped while the relay is open. 10. The relay according to claim 9, wherein the short-circuiting of the relay is performed after waiting for a predetermined time from the start of operation of the second DC power supply, and the operation of the second DC power supply is performed after waiting for a predetermined time after opening of the relay. Induction heating cooker.