JPH07235372A - High power cooking apparatus - Google Patents

Abstract

PURPOSE:To make cooking with heat satisfactorily even with commercial electric supply by supplying the heating means with either of AC signal from the AC electric supply and DC signal from a battery which is the greatest. CONSTITUTION:A resonance circuit 4 formed from a capacitor C2 and an induction heating coil L2 is controlled by an IGBT 7 turned on and off by a control circuit 6 so that high frequency waves are generated, and thereby a material to be cooked is induction heated and cooked. The voltage of AC signal given by an AC power supply 1 supplied to this circuit 4 is compared with the voltage of a DC signal given by a battery 2, and comparator 9 supplies a minus output to a CPU 8 when the AC signal voltage is bigger and a plus output when lower. Thus the CPU 8 controls a transistor Tr, and the resonance circuit 4 is supplied with either of the AC and DC signals whose voltage is higher, and satisfactory cooking with heat can be made even with commerical electric supply.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a high power cooker capable of cooking and heating an object to be cooked with a sufficient amount of heat even though it is a commercial AC power source.

[0002]

2. Description of the Related Art Conventionally, the problems to be solved by the invention
In a domestic electric cooker, for example, an electromagnetic heating cooker, a commercial power source is used to heat a food item. In this cooking and heating, for example, in the case of an electric cooker for AC100V, the maximum power consumption value can be suppressed to 1500W.

Therefore, there is a problem that the amount of heat that can be applied to the food to be cooked is smaller than that of a gas stove and the like, and sufficient cooking and heating cannot be performed. Therefore, in view of the above problems, it is an object of the present invention to provide a high power cooker that can perform sufficient cooking and heating even with a commercial AC power supply.

[0004]

In order to achieve the above-mentioned object, the present invention makes a high-power cooker generate heat with a heater by alternating current from an alternating current power source, or performs full-wave rectification of alternating current from the alternating current power source, In a high-power cooker in which a heating element is used to directly or induction-heat a heated object by generating a high frequency in an induction heating coil with a switching element, a direct current larger than at least the minimum instantaneous value of the alternating current voltage supplied from the alternating current power source. A storage battery that supplies a voltage, and in a range where the instantaneous value of the AC voltage is smaller than the DC voltage value from the storage battery, a DC supply unit that supplies a DC voltage from the storage battery to the heater or the induction heating coil is provided. is there.

While the heating means is composed of an induction heating coil which is turned on and off by a switching element, the duty ratio of the pulse signal emitted from the switching element is adjusted to maintain the power consumption of the heating means at a predetermined value. High power maintaining means may be provided.

While the heating means is composed of a heater, a power selecting means for converting the DC voltage input from the storage battery to the DC supply means into only one corresponding to either positive or negative of the AC voltage is provided. May be.

While the heating means is composed of a heater, two storage batteries are provided, and power conversion means for converting a DC voltage from each storage battery according to the positive / negative of the AC voltage input to the DC supply means is provided. You may do it.

If the remaining charge level is detected to be less than or equal to a predetermined value based on the remaining charge level detection means for detecting the remaining charge level of the storage battery and the detection signal from the remaining charge level detection means, the storage battery switches to the heating means. DC stop means for stopping the signal input of may be provided.

[0009]

Embodiments of the present invention will be described below with reference to the accompanying drawings. FIG. 1 shows an electric circuit of a high power cooker according to the first embodiment. This is applied to an IH (which utilizes induction heating) cooker, and an AC power supply 1 and a storage battery 2 are used as a power supply.

A full-wave rectifier circuit 3 is connected to the AC power source 1. The full-wave rectifier circuit 3 is connected via a coil L ₁ and a capacitor C ₁ to a resonance circuit 4 composed of an induction heating coil L ₂ and a capacitor C ₂ which are heating means, and is connected to a storage battery 2 via a charging circuit 5. It is connected. A high frequency is generated in the resonance circuit 4 by the IGBT 7 which is turned on / off based on a control signal from the control circuit 6. Thereby, the inner container (not shown) or the like is induction-heated, and the food can be cooked and heated. The control circuit 6 is driven based on a control signal from a central processing unit (CPU) 8. Moreover, it said the AC power supply 1 is a variable resistor R ₂ is connected to the resistor R ₁ and the ground through the diode D _1, between the resistor R ₁ and the variable resistor R ₂ is connected to the negative input terminal of the comparator 9 ing.

On the other hand, the storage battery 2 has a transistor Tr.
The emitters of are connected. The transistor Tr is turned on / off by the driver 10 connected to the base via the resistor R ₅ , and the driver 10 is driven by the control signal from the CPU 8. Also, the transistor Tr
Together with the collector is connected to the resonant circuit 4 side via the diode D _2, resistors R _3, R ₄ is grounded via a resistor R _3, while R ₄ is the positive input terminal of the comparator 9 It is connected to the. The collector and base of the transistor Tr are connected via a resistor R ₆ . Further, the storage battery 2 includes a resistor R ₇ and a variable resistor R ₈ grounded.
The CPU 8 is connected to the CPU 8 via the, and the storage voltage of the storage battery 2 is constantly input to the CPU 8.

As described above, the comparator 9 includes the AC power source 1
A voltage that is full-wave rectified by the diode D ₁ is input from the battery, and a DC voltage is input from the storage battery 2 (see FIG. 2B). Based on these input signals, the comparator 9 outputs a negative signal to the CPU 8 if the full-wave rectified voltage is larger, and outputs a positive signal to the CPU 8 if the DC voltage is larger. By adjusting the resistance value of the variable resistor R ₂ , it is possible to set at what percentage of the maximum value the instantaneous value of the full-wave rectified signal is to output the negative signal. In the first embodiment, the DC voltage is about 50% of the AC voltage peak value.

The CPU 8 performs induction heating control according to the flow chart of FIG. 3 based on the input signals from the comparator 9, the storage battery 2 and the like. That is, first, step S
At 1, it is determined whether induction heating has started. This determination is made based on an input signal from a power switch (not shown). Next, in step S2, the voltage of the storage battery 2 is read, and in step S3, it is determined whether the read output voltage value of the storage battery 2 is greater than or equal to the reference voltage value. If it is equal to or higher than the reference voltage value, the driver 10
Then, the transistor Tr is turned on by issuing a control signal. If it is less than the reference voltage, step S
Go to 8.

If the transistor Tr is turned on in step S4, a high power operation is performed in step S5. In this high power operation, as shown in FIG.
As shown in (d) and (e), when the voltage from the AC power source 1 is higher than the voltage from the storage battery 2, the diode D ₂ is reverse-biased, and therefore the induction heating coil L ₂ receives only the full-wave rectified signal. Is input (see FIG. 2D), and in the opposite case,
The induction heating coil L ₂ forward bias is applied to the diode D ₂ only a DC voltage is input (see FIG. 2 (e)). As a result, the supply voltage to the induction heating coil L ₂ is automatically selected, and the waveform shown in FIG. 2C is obtained.

Further, the pulse duty ratio of the IGBT 7, that is, the on / off timing is changed based on the input signal from the comparator 9, so that the power consumption in the induction heating coil L ₂ is always maintained at a high value. To control.
Specifically, the on-time of the IGBT 7 is lengthened except when the instantaneous value of the input voltage to the induction heating coil L ₂ is in a high range including its maximum value. As a result, the power consumption of the induction heating coil L ₂ can be increased as compared with the case where only the full-wave rectified voltage is supplied (in this embodiment, about 1700 W) and the heating power of induction heating is increased. We were able to.

Then, in step S6, it is determined whether or not cooking and heating has been stopped based on the input signal from the power switch. If stopped, the process proceeds to step S11, and if not stopped, in step S7, it is determined whether or not the DC supply time from the storage battery 2 has passed the time limit, and the high power operation is performed until the time has passed. Let In this case, the time limit is set to a value at which the remaining charge of the storage battery 2 is estimated to be equal to or less than a predetermined value.

However, as described above, instead of stopping the high power operation based on the time limit, the stored voltage value is read in step S12 and this voltage value is read in step S13 as shown in the flowchart of FIG. By determining whether the voltage is equal to or lower than a preset lower limit voltage value, the high power operation may be stopped if the lower limit voltage value is equal to or lower than the lower limit voltage value, and may be continued if the lower limit voltage value is equal to or lower than the lower limit voltage value .

When the stored voltage decreases in this way, in step S8, a control signal is issued to the driver 10 to turn off the transistor Tr, and the DC signal from the storage battery 2 input to the induction heating coil L ₂ is cut off. Then, in step S9, the conventional induction heating is performed by inputting only the full-wave rectified signal to the induction heating coil L ₂ . Subsequently, in step S10, it is determined whether or not the heating is stopped, as in step S6, and the normal control of step S9 is continued until the heating is stopped.
At 1, the normal operation ends.

FIG. 5 is an electric circuit diagram of the high power cooker according to the second embodiment. In this electric circuit, the AC power supply 11
A heater 12 and a three-terminal bidirectional thyristor 13 and an AC positive polarity detector 14 are connected to each other via a coil L ₃ . The output terminal of the AC positive polarity detector 14 is connected to one input terminal of the AND circuit 15, and the control signal from the CPU 16 is input to the other input terminal of the AND circuit 15.

The output terminal of the AND circuit 15 is connected to the negative side of the storage battery 19 via the driver 17 and the FET 18. The FET 18 and the storage battery 19 are grounded via a relay 20, and the relay 20 is connected to the C
The driver 21 receives the control signal from the PU 16 to open and close it. Further, the storage battery 19 is
It is connected to the heater 12 via a charging circuit 22 and a diode D ₃ which are connected in parallel. The storage battery 19
The storage voltage of is detected by the CPU 16 as in the first embodiment.

In the electric circuit having the above construction, the AC voltage generated from the AC power supply 11 (see FIG. 6A) is converted into pulses by the AC positive polarity detector 14 and input to the AND circuit 15 ( See FIG. 6B). AND circuit 15 is C
The negative side of the AC signal converted into a pulse shape based on the input signal from the PU 16 is cut (see FIG. 6C). The FET driver 17 is an FET based on only the plus-side pulse signal input from the AND circuit 15.
18 is driven, so that the DC voltage output from the storage battery 19 also has the same waveform.

In the heater 12, as shown in FIG. 6 (d), the negative voltage of the AC voltage remains unchanged, and the positive voltage is higher than the DC voltage from the storage battery 19, the diode D.
_A reverse bias is applied to ₃ to input an AC voltage, and in the opposite case, the diode D ₃ is forward biased to input a DC voltage. Therefore, the power consumption of the heater 12 is larger than that in the case of supplying only the AC voltage. Also,
In the second embodiment, the DC voltage is about 50% of the peak value of the AC voltage.
I am doing it.

The cooking and heating in the second embodiment is controlled according to the flow chart of FIG. 3 or 4 as in the first embodiment. However, in the second embodiment, the high power operation is performed as follows. That is, the timing of supplying the AC voltage as it is to the heater 12 and applying the DC voltage from the storage battery 19 is controlled by the FET driver 17 via the AC positive polarity detector 14, the CPU 16 and the AND circuit 15, as described above. It is adjusted by the FET 18. The storage battery 19 is charged via the charging circuit 22 by issuing a control signal to the driver 21 to turn on the relay 20.

Further, in the second embodiment, the plus of the AC voltage is compared with the DC voltage, and the signal for increasing the power consumption in the heater 12 is inputted, but the DC voltage is inversely converted into the minus. Heater 1 with negative AC voltage
It is also possible to supply a voltage that increases the power consumption in No. 2.

FIG. 7 shows an electric circuit of the high power cooker according to the third embodiment. This electric circuit is provided with a pair of each of the driver 17, the FET 18, the storage battery 19 and the charging circuit 22 shown in the second embodiment (hereinafter, the plus side is indicated by a suffix a and the minus side is indicated by a suffix b). .

Power is supplied from the AC power supply 11 to the non-zero cross detector 21, the isolation circuit 22, and the CPU 2.
3, the AND circuit 24, the AC positive polarity detector 25, and the inverter 26 separately perform the plus side and the minus side.

That is, the AC signal input to the non-zero cross detector 21 is converted into an impulse that emits a pulse signal only when it reaches zero. This signal is input to the AND circuit 24 together with the control signal from the CPU 23 via the isolation circuit 22. The AND circuit 24 issues an output signal to the AND circuits 15a and 15b connected to the drivers 17a and 17b based on these input signals. In addition, the pulse signals from the AC positive polarity detector 25 and the pulse signals inversely converted by the inverter 26 are input to the AND circuits 15a and 15b, respectively. Each AND circuit 1
Reference numerals 5a and 15b output control signals to the drivers 17a and 17b, respectively, based on the output signal from the AND circuit 24 and the pulse signal from the AC positive polarity detector 25 or the pulse signal inversely converted by the inverter 26. , And the corresponding FETs 18a and 18b are turned on / off.

When the AC voltage from the AC power source 11 is positive, the FET 18a is turned on and the FET 18b is turned off, and the plus voltage is supplied to the heater 12 by the AC signal and the DC voltage from the storage battery 19. If the AC voltage from the AC power supply 11 is negative, the FET 18
When a is in an off state and FET 18b is in an on state, a negative voltage is applied to the heater 12 by the alternating voltage and the direct voltage from the storage battery 19. As described above, the heater 12 is energized with a signal having a waveform as shown in FIG. 8 (g), and the power consumption of the heater 12 is increased as compared with the second embodiment, so that more effective cooking and heating can be achieved. Can be performed. Also in the third embodiment, the DC voltage is about 50% of the peak value of the AC voltage.

In the third embodiment, the non-zero cross detector 21 outputs the OFF signal only when the AC signal becomes zero to control the FETs 18a and 18b on / off. It may be performed based on a pulse signal (impulse) output when the AC signal becomes zero by the zero-cross detector.

[0030]

As is apparent from the above description, according to the high power cooker of the present invention, not only the AC power source but also the storage battery is used, so that the power source having the higher voltage is used as the target. Since the object to be heated is heated, it is possible to increase the heating power as compared with the conventional case, and it is possible to perform desired cooking and heating, which is the same as that of a gas stove or the like, despite being an electric cooker.

Further, when high frequency is generated in the coil for induction heating, the duty ratio of the pulse signal output from the switching element is adjusted so that the power consumption in the heating means can be maintained at a predetermined value. Therefore, it is possible to obtain a desired heating power regardless of the decrease in the input signal.

Further, in the case of heating with a heater, if a power selecting means or a power changing means is provided, it is possible to obtain a desired heating power while directly using the alternating current from the alternating current power source for heating with the heater.

Furthermore, the remaining charge of the storage battery is detected,
If the supply of the direct current from the storage battery is stopped based on the remaining amount of the stored power, the storage battery can be prevented from discharging in a state where it does not contribute to the heating of the heating means, and the storage battery can be charged during that time.

[Brief description of drawings]

FIG. 1 is an electric circuit diagram of a high power cooker according to a first embodiment.

FIG. 2 is a graph showing a signal waveform in each part of FIG.

FIG. 3 is a flowchart showing cooking and heating control in the CPU of FIG.

FIG. 4 is a part of a flowchart showing another embodiment of FIG.

FIG. 5 is an electric circuit diagram of a high power cooker according to a second embodiment.

FIG. 6 is a graph showing a signal waveform in each part of FIG.

FIG. 7 is an electric circuit diagram of a high power cooker according to a third embodiment.

FIG. 8 is a graph showing a signal waveform in each part of FIG.

[Explanation of symbols]

1 ... AC power supply, 2 ... Storage battery, 4 ... Resonance circuit, 7 ... IGB
T, 8 ... Central processing unit (CPU), 9 ... Comparator.

Claims (5)

[Claims] 1. An object to be heated is directly or induced by causing a heater to generate heat by an alternating current from an alternating current power source or full-wave rectifying the alternating current from the alternating current power source and generating a high frequency in an induction heating coil by a switching element. In a high-power cooker configured to heat, a storage battery that supplies a DC voltage larger than at least the minimum instantaneous value of the AC voltage supplied from the AC power source, and the instantaneous value of the AC voltage is the DC voltage value from the storage battery. In a smaller range, a high power cooker is provided with a DC supply means for supplying a DC voltage from the storage battery to the heater or the induction heating coil. 2. The heating means is composed of an induction heating coil which is turned on and off by a switching element, and the duty ratio of a pulse signal emitted from the switching element is adjusted to set the power consumption of the heating means to a predetermined value. The high power maintaining means for maintaining is provided.
High power cooker as described. 3. The heating means comprises a heater,
DC voltage input from the storage battery to the DC supply means,
The high-power cooker according to claim 1, further comprising a power selection unit that converts only the positive or negative of the AC voltage. 4. The heating means comprises a heater,
The power conversion means for converting the direct current voltage from each storage battery according to the positive / negative of the alternating voltage input to the direct current supply means is provided.
High power cooker as described. 5. The storage battery is heated from the storage battery when the storage battery remaining amount detecting means for detecting the storage battery remaining amount of the storage battery and the storage battery remaining amount is judged to be a predetermined value or less based on a detection signal from the storage battery remaining amount detecting means. 5. A direct current stopping means for stopping signal input to the means is provided.
High power cooker described in 3.