JPH05226071A - High frequency heating device - Google Patents

Abstract

PURPOSE:To provide a desired large output regardless of a power capacity of an external power supply by using power of a storage battery. CONSTITUTION:A device comprises a power converting part 33 to receive power of an external power supply 31, an electric wave radiation part 34 to receive power from the power converting part 33 and output high frequency waves, and a storage battery 37 to supply power to the power converting part 33. A total power of the external power supply 31 and the storage battery 37 is power converted at the single power converting part 33 to be supplied to the electric wave radiation part 34, so a subject matter is heated by electric waves at power exceeding the power of the external power supply 31. In this constitution, a high frequency output can be set large with high safety and reliability, thereby high-speed cooking is enabled.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a high frequency heating device such as a microwave oven.

[0002]

2. Description of the Related Art A conventional high-frequency heating apparatus, as shown in FIG. 7, includes a rectifier 2, an inductor 3, and a capacitor 4, which rectify the electric power supplied from a commercial power source 1 into a DC voltage.
A rectifier circuit including a capacitor 5, a transistor 6, a diode 7, and an inverter circuit including a step-up transformer 8, a high-voltage capacitor 9, and a high-voltage diode 10.
And a high-voltage rectifier circuit 11 and a magnetron 12 that receives the output of the high-voltage rectifier circuit and generates a high-frequency radio wave output.
And a control circuit 13 for controlling the operating frequency of the transistor 6 and a relay 14, and the control circuit 1
3 is composed of a heating control unit 15 and the like for giving a heating command.

8 (a), (b) and (c) show the terminal voltage Vac of the capacitor 4 which is the input voltage of the inverter circuit, the collector-emitter voltage Vce of the transistor 6 and its envelope, and the magnetron 12 respectively. 3 is an envelope waveform of the anode current Ia. The actual Ia waveform has an envelope as shown in the figure and has a high-frequency current ripple similar to Vce. The period during which the magnetron 12 is oscillating is only the period during which Ia flows, which is indicated by the broken line in the figure, and is only when Vac is equal to or higher than the threshold voltage of the magnetron 12. It is shown that. That is, in order to prevent the input power factor of the input terminal (that is, the AC terminal of the rectifier 2) of the high-frequency heating device from decreasing, the terminal voltage of the capacitor 4 has to have a voltage waveform as shown in FIG. Therefore, the magnetron 12 oscillated intermittently as shown in FIG. On the other hand, the transistor 6 is shown in FIG.
As in (b), it operates during the period in which Ia does not flow, and during this period, the transistor 6 is uselessly operated although it hardly contributes to the microwave oscillation for the magnetron 12.

In addition, many commercial power outlets in general households have a rating of 15A and many households have a power wiring rating of 20A. Therefore, the maximum current consumption of a high frequency heating device such as a microwave oven is 13 to 14A. I had to keep it to a degree. Even if the indoor wiring current capacity is 20A, there are devices such as rice cookers and toasters that are used at the same time, and the current consumption is often 6 to 7A.
This is because there are many cases where only ~ 14A can be used, and the maximum current capacity of the outlet in the home is 15A in most cases.

Therefore, in the conventional high-frequency heating apparatus, the oscillating operation period of the magnetron 12 is about one half of the entire operating period, and the input current from the commercial power source or the like is limited. In the case of a device with a power supply specification, its input power was normally limited to about 1.3 to 1.4 kW. Therefore, most of the output power of the conventional high frequency heating device is limited to about 600 W at maximum,
The maximum output is 700W with a short-time rating,
Only a high-frequency heating device with such a radio wave output has been put to practical use.

Further, as shown in FIG. 9, the rectifier 16 rectifies the voltage of the commercial power source 1 to convert it into a DC voltage, and
A storage battery 17 is provided and is switched by switches 18 and 19 to supply it to the DC-DC booster circuit 20.
A high-frequency heating device configured to supply electric power to the magnetron 12 via a heater is disclosed in Japanese Patent Publication No. 56-21237. This high-frequency heating device is intended to obtain a radio wave output of 600 W (input of 1200 W) even in a home with a small contract power, and stores energy in the storage battery 17 when the device is not used and when the device is not used. The energy stored in the above is taken out to drive the magnetron 12 to achieve the above object.

[0007]

However, the conventional configuration shown in FIG. 7 is limited by the input current from the commercial power source, and only a radio wave output of about 600 (-700 W) corresponding to that is obtained. However, there is a problem that it is difficult to further enhance the feature of the high-frequency heating device that is high-speed heating (high-speed cooking). Further, in the case of the conventional configuration of FIG. 9 using a battery, since a considerably large energy storage capacity is required, the entire apparatus becomes large and expensive, and high voltage and high power (about 1.2 kW at 100V). There was a problem that it was necessary to switch the output of the storage battery. Further, it is disclosed in Japanese Patent Publication No. 56-21237 that the output voltage of the storage battery 17 and the electric power of the commercial power source 1 can be supplied to the magnetron 12 at the same time. However, there are problems that the input power factor from 1 is remarkably reduced, unstable operation is caused by internal impedance mismatch and output voltage mismatch of both power sources, or the storage battery is deteriorated. For this reason, it was practically difficult to realize such a configuration. As a result, the output of the high-frequency heating device must be limited by the input current from an external AC power source such as a commercial power source, and the problem that the radio wave output is limited to about 700 W at a 100 Vac input voltage is solved. could not.
Therefore, it is extremely difficult to realize a high-frequency heating device that is not limited by the current capacity of an external power source such as a commercial power source and that has a higher high-frequency output and can achieve high-speed heating (cooking), and that has a compact and lightweight structure. However, there is a problem that it is not possible to realize a high-frequency heating device adapted to the modern diet, which requires higher-speed cooking.

The present invention solves the above problems and can be easily realized while preventing an increase in size, complexity, and cost, and a large high-frequency output without being restricted by an input current from an external power source such as a commercial power source. The purpose of the invention is to significantly improve the features of the high-frequency heating device, to ensure its safety and reliability, and to extend its service life. Further, it is an object of the present invention to provide a high frequency heating device capable of exhibiting a high power factor performance of input power when the external power supply is an AC power supply. Furthermore, it is an object of the present invention to provide a high-frequency heating device that enables easy and reliable repeated use of a storage battery and can always obtain a large high-frequency output without being limited by the input current.

[0009]

The present invention has the following constitution in order to achieve the above object. That is,
An electric power converter that converts electric power supplied from an external power source such as a commercial power source, a radio wave radiating unit that receives the converted power from the power converter and radiates high-frequency power to a heating chamber, and a storage battery, and the external power source The sum power of the storage battery is converted by the single power conversion unit and supplied to the radio wave radiation unit.

Further, the external power source is constituted by an AC power source, the power converter is configured to include a full-wave rectification circuit and an inverter circuit, and the direct output or boosted output of the storage battery and the full-wave rectification circuit are provided. Is supplied to the inverter circuit, and the sum output of the both outputs is converted into power by a single inverter circuit.

Further, the full-wave rectifying means and the storage battery are connected in parallel via the rectifying means, and the rectifying means prevents the current from flowing from the full-wave rectifying means to the storage battery side. ..

Furthermore, a charging means for charging the storage battery is provided, and the storage battery is charged by the electric power of the external power source.

Further, the storage battery is charged by the power of the external AC power supply when the operation of the power conversion unit is stopped.

[0014]

The present invention has the above-described structure and achieves the following operations. A power conversion unit, a radio wave emission unit, and a storage battery, by the power conversion of the sum power of the external power source and the storage battery by the single power conversion unit, by a configuration to supply to the radio wave emission unit, The power of the storage battery and the power of the external power supply is converted with a single power converter while maintaining a high level of matching, and the radio wave radiating part generates an extremely large radio wave output that is not limited to the maximum allowable power of the external power supply. Then, the object to be heated is heated.

Further, the power converter is configured to include a full-wave rectification circuit and an inverter circuit, and the direct output of the storage battery or the boosted output and the output of the full-wave rectification circuit are supplied to the inverter circuit, By having a configuration in which the sum output of the both outputs is power converted by a single inverter circuit,
The sum power is obtained with an extremely simple configuration, and this sum power is converted into power by a single inverter circuit, generating a very large radio wave output that is not limited to the maximum allowable electric power of the external power source from the radio wave radiating part and heating the object to be heated. The effect of heating the.

Further, the full-wave rectification means and the storage battery are connected in parallel via the rectification means, and the rectification means prevents a current from flowing from the full-wave rectification means to the storage battery side. It prevents the occurrence of inconveniences such as power factor reduction of external AC power supply and instability phenomenon due to impedance mismatch, maintains high matching, and converts the sum power into a single power converter, Therefore, an extremely large radio wave output that is not limited to the maximum allowable electric power of the external power source is generated to heat the object to be heated.

Furthermore, by providing a charging means for charging the storage battery and charging the storage battery with the electric power of the external power source, the storage battery can be charged safely and surely with the electric power of the external power source, and charging and discharging are repeated. However, the function of supplying the sum power of the storage battery and the power of the external power source to the power conversion unit is easily maintained for a long period of time while maintaining high consistency.

Further, the storage battery is charged by the power of the external AC power supply when the power conversion unit stops operating, so that the power of the external power supply is always maximized when the power conversion unit operates. As a result, the discharge power of the storage battery can be used as a necessary minimum level. By charging the battery during the period in which the power conversion unit does not operate, the power of the storage battery can be always used in the maximum charged state, and a large radio wave output is generated.

[0019]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to FIG.

In FIG. 1, 31 is a commercial power source or generator,
It is an external power source such as a DC power source and supplies AC or DC power to the high frequency heating device 32 from the outside. The high frequency heating device 32 receives an electric power conversion unit 33 that converts this electric power, and an electric wave that receives the electric power converted by the electric power conversion unit 33 to generate a high frequency electric wave (for example, a microwave) and supply it to a heating chamber (not shown). It has a radiator 34. This power converter 33
Can be configured by, for example, the power converter 35 and the converter control unit 36. The high frequency heating device 32 further includes a storage battery 37.
This output is connected in parallel with the external power supply 31 via the backflow prevention means 44 to supply power to the power conversion unit 33. The storage battery 37 may be built in the housing of the high-frequency heating device, or may be provided outside the housing and easily exchangeable. The storage battery 37 is configured to be charged with energy from an external power source via the charging means 39, and the storage battery can be used semipermanently without replacing the battery.

The heating control section 41 controls the converted power of the power conversion section 33 by controlling the converter control section 36, for example, and adjusts the magnitude of the output radio wave of the radio wave emission section 34. In addition, the heating control unit 41 uses, for example, the backflow prevention unit 4
4, a control unit (not shown) is provided, and by controlling the control unit, the power of the storage battery 37 is added to the power from the external power supply 31 in parallel and is supplied to the single power conversion unit 33. .. Since a high output performance is required for this storage battery 37, a so-called lead storage battery, a Li-based storage battery or the like is suitable. In actual use, from the viewpoint of safety in terms of voltage, reliability of contact, etc., or productivity in terms of manufacturing, etc.
2V to 24V is more suitable. Therefore, in another embodiment shown in FIG. 2, the output of the storage battery 37 having an output voltage of 24 V is boosted by the booster 38, and this boosted output is supplied to the external power source 3
1 is connected in parallel to the power conversion unit 33 and is supplied to the power conversion unit 33. In this embodiment, the external power source 31 is an AC power source,
The output voltage of the storage battery 37 is adjusted to a desired value below the instantaneous maximum voltage (141 V when the external AC power supply is a commercial 100 V power supply). This adjustment is performed based on the command signal of the heating control unit 41, and can be performed in harmony with the control of the power conversion unit 35. And especially
The output voltage of the storage battery 37 is adjusted to a desired value below the instantaneous maximum voltage of the AC external power supply 31 so that the high frequency heating device 32 does not have a low power factor with respect to the AC external power supply 31.

In FIG. 2, the diode bridge 42 is originally included in the power conversion unit 33, but is shown separately for ease of explanation. With this configuration, the AC voltage of the commercial power supply 31 becomes a high ripple unidirectional voltage having a full-wave rectified waveform and is supplied to the inverter circuit that constitutes the power converter 35. The output voltage of the storage battery 37 is connected in parallel to the supply line 43 via the diode 44 as the output of the booster 38 and is supplied, and such a parallel connection configuration makes it extremely easy to use the external power supply 31 and the storage battery. The sum power of 37 can be supplied to the single power converter 33. At the same time, the backflow prevention unit 44 can prevent inconveniences such as danger and shortening of life due to overheating of the storage battery 37 due to excessive inflow current from the external power supply 31 to the storage battery 37.

FIGS. 3A and 3B are individual output voltage waveform diagrams Vac and Vdc of the diode bridge 42 and the reverse current blocking means (diode) 44, respectively. In this configuration, changing the magnitude of Vdc changes the AC input power factor. FIG. 4 is an experimental result showing this characteristic. When the DC voltage Vdc supplied from the storage battery 37 is increased while controlling the effective value of the input current from the commercial power source 31 of 100 Vac in FIG. 2 to be about 13.5 A constant, the input power factor gradually increases from several tens of V. Begins to drop to 90% at about 100V
It becomes a power factor of the degree. If Vdc is further increased, the power factor will be rapidly reduced. This is because the power source impedance on the side of the storage battery 37 including the booster 38 is inevitably lower than the power source impedance of the commercial power source 31. That is, in the configuration of FIG. 2, when Vac in FIG. 3A is equal to or higher than the voltage (broken line) corresponding to Vdc in FIG. 3B, electric power is supplied from the commercial power source 31, while when Vac is lower than that. The electric power is supplied from the storage battery 37. Therefore, the storage battery 37
The voltage supplied from the power converter 35 to the power converter 35 has a square wave shape having a peak voltage Vdc as shown in FIG. In such a parallel connection configuration of the external power supply 31 and the storage battery 37, the voltage supplied to the power converter 35 is as shown in FIG. 4B even when the output of the booster 38 is constant Vdc, so that the booster It is not necessary to control the output voltage of 38 according to the instantaneous value of the commercial power supply 31.

5 (a), (b), (c) and (d)
Indicate the envelopes of Vac, Vdc, the sum voltage Vin of Vac and Vdc (the input voltage of the power converter 35) and the anode current Ia of the magnetron, which is the radio wave radiation unit 34, respectively. As is clear from comparison with the case of the conventional example shown in FIG. 9, the peak value of the envelope waveform of Ia with respect to Vac does not increase, and the average value is greatly increased although it is the same as the conventional case. This is the effect of the sum power generation circuit configuration that can be easily realized by configuring the external power source 31 and the storage battery 37 in parallel as shown in FIG. 1 or 2 and performing the power conversion by the single power converter 35. is there.
Further, although not shown in FIG. 5, the voltage Vce applied to a transistor or the like that constitutes the power converter 35 is also Vin.
Since it is as shown in FIG. 5C, the peak value is of course the same as that of the conventional one, and no special high breakdown voltage parts are required. As described above, it is not necessary to make the peak values of the anode current Ia of the magnetron and the transistor voltage Vce (of course, the same for the current) larger than those of the conventional ones, and moreover, it is possible to simplify the structure without significantly reducing the input power factor from the external power source. To increase the conversion power of the single power conversion unit 33,
As a result, the output radio wave from the radio wave emitting section 34 can be made sufficiently large. Specifically, in the configuration of FIG.
Input power from commercial power supply 31 is about 1200W, about 13.5
If A is set to A and Vdc is set to about 105 V, the storage battery 37
Is supplied with about 800 W, and the power converter 35 can convert about 2000 W. As a result, the magnetron 34 can generate a radio wave output of about 1000 W, which makes it possible to significantly shorten the cooking time as compared with the conventional one, and does not cause a disadvantage such as a significant decrease in power factor. Current 13-14
The above large radio wave output can be exerted while maintaining a desired value of about A or less. Further, by providing the backflow prevention means 44, it is possible to prevent an excessive current from flowing from the external power source 31 to the boosting means 38 and the storage battery 37, prevent inconveniences such as overheating, destruction, and shortening of life, and have high safety and high reliability. It is possible to provide a high-frequency heating device that guarantees a long life and enables a large output with a simple circuit configuration having only a single power conversion unit.

FIG. 6 is a circuit diagram showing a more detailed structure for realizing one embodiment of the present invention shown in the block diagram of FIG. 2, and the same reference numerals as those in FIG. 2 are the corresponding constituent elements. FIG. 6 is a circuit diagram of a high frequency heating device using a commercial power supply 31 as an external power supply. The power conversion unit 33 includes a DC power supply having a full-wave rectification-like waveform including a diode bridge 42, an inductor 51 and a capacitor 52, and a resonance. Capacitor 5
3, a step-up transformer 54, a transistor 55, an inverter including a diode 56, a high-voltage rectifying circuit including a capacitor 57 and diodes 58 and 59, and a heater circuit including a resonant capacitor 60 and inductors 61 and 62. The radio wave emitting unit 34 is the magnetron 6
It is composed of three. Converter control circuit (converter controller)
36 controls the switching frequency of the transistor 55 to operate the inverter, and high-voltage power and heater power are supplied to the magnetron 63 to oscillate and radiate radio waves to the heating chamber. The details of the basic power conversion operation of the inverter are well known and therefore omitted, but the converter control circuit 36 is omitted.
Is a heating control unit 4 including a microcomputer 64 and the like.
Based on the signal of No. 1, while stabilizing the radio wave output by the signals of the current transformers 65 and 66, the transistor 55
To control the magnitude of the radio wave output.

The storage battery 37 preferably has a voltage of about 12 to 24 V from the viewpoint of safety and manufacturing cost. Therefore, the storage battery 37 is configured to supply power to the power conversion unit 33 via the booster circuit (boosting unit) 38. The step-up circuit 38 is a so-called step-up DC / DC converter including a step-up inductor 67 with a tap, capacitors 68 and 69, a transistor 70, a diode 71, and a control circuit 73. By controlling the on / off ratio by the control circuit 73, the terminal voltage of the capacitor 69 (that is, the DC output voltage) can be adjusted. The output of the booster circuit 38 is connected in parallel to the output of the diode bridge 42 via a diode 44 which is a backflow prevention means so that the sum power can be easily obtained.

The heating control section 41 closes the relay contacts 74 and 75 and controls the converter control circuit 36 and the booster circuit 38 during the heating operation of the high-frequency heating device.
The operation command is given to 3. Therefore, the inverter forming the center of the power conversion function of the power conversion unit 33 is the commercial power supply 31.
And the electric power from the storage battery 37 boosted by the booster circuit is received to perform the power conversion operation.

With the specific configuration described above, the power conversion operation and high frequency heating operation described in FIGS. 2, 3, 4 and 5 can be realized. In such a configuration, the average value can be increased without increasing the maximum value, and thus the transistor 5 that constitutes the power conversion unit 33 can be configured.
This is a very desirable operating condition for the semiconductors such as No. 5 and the resonance capacitor 53, and it is possible to easily convert the electric power about twice as much as the conventional one by using relatively low-priced parts. In addition, the storage battery 37 is connected in parallel to the commercial power source 31 in this way, and Vd is set only when the instantaneous voltage of the commercial power source 31 is low.
By supplying c, it is extremely easy to superimpose Vdc on the voltage Vac from the commercial power source while maintaining the power factor of the input power from the commercial power source 31 at a relatively high value. As described above, it is possible to provide a high-frequency heating device having a high input power power factor even with control. In addition, as shown in FIG.
The operation of the booster circuit 38 may be synchronized and intermittently performed according to the instantaneous value of Vac, but if the capacity of the smoothing capacitor 69 is set sufficiently larger than the cycle of the commercial power supply, the booster circuit 38 is provided.
Does not require an intermittent operation, and similar performance can be obtained even when the continuous operation is performed. That is, Vdc may be a constant voltage of 105 V as described above,
In this case, the booster circuit 38 need only be operated so as to obtain an average DC output of 105 V regardless of the instantaneous value of the commercial power supply voltage. Therefore, in this case, the capacitor 6
Instead of increasing the capacity of 9, the booster circuit 38 only needs to perform an average operation (for example, an operation at a substantially constant frequency), and its control becomes relatively simple, and the transistor 70 and the like handle average power. Since the maximum current and the maximum voltage can be suppressed to a low level, the storage battery 3
When the power supplied from 7 is large, this is more desirable in terms of price or conversion efficiency.

Further, as is apparent from FIG. 6, when the reverse current blocking diode 44 is not provided, an excessive current flows from the commercial power source 31 to the capacitor 69 via the diode bridge 42, and the capacitor 52 and the like are also connected to the booster circuit 38. Since it becomes a direct load, the boosting operation becomes unstable. Further, in the case of the configuration in which the booster circuit 38 is not provided and the storage battery 37 is directly connected in parallel to the diode bridge 42, an excessive current flow into the storage battery 37 occurs, so that the storage battery 37 is destroyed due to heat generation, such as an explosion.
Inconvenience such as shortening of life occurs. Therefore, the reverse current blocking diode 44 plays an extremely important role when the sum power of the external power source 31 and the storage battery 37 is converted by the single power converter 33.

The heating control section 41 opens the relay contacts 74 and 75 and also contacts the contact 76 when the operation of the high-frequency heating device is stopped.
And the charging circuit (charging means) 39 is operated to close the storage battery 3
7 is charged and the electric energy discharged by the previous heating operation is automatically recharged. Charging circuit 3
Reference numeral 9 is a step-down DC that converts a DC voltage obtained by the diode 77 and the capacitor 78 into a voltage suitable for charging the storage battery 37 by the transistor 79, the diodes 80 and 81, the inductor 82, the capacitor 83, and the control circuit 84. / DC converter, which can arbitrarily adjust the output voltage according to the on / off ratio of the transistor 79, and its detailed circuit operation is already well known, and therefore its explanation is omitted.

With such a configuration, the power supply from the commercial power supply 31 to the charging circuit 39 can be reduced to zero during the operation of the power converter 33. Therefore, the maximum power that can be supplied from the commercial power supply 31 is converted into a desired large radio wave. You can get the output.

[0032]

As described above, the high frequency heating apparatus of the present invention has the following effects.

That is, the power conversion section, the radio wave radiation section,
A storage battery is provided, and the total power of the external power supply and the storage battery is converted by the single power conversion unit and supplied to the radio wave radiating unit, so that the sum power of the storage battery and the power of the external power supply is obtained. It is possible to heat the object to be heated by converting the power with a single power converter while maintaining high consistency, and generating an extremely large radio wave output from the radio wave radiating section that is not limited to the maximum allowable power of the external power supply. A possible high-frequency heating device can be provided. And, in particular, since it is configured to convert the sum power by a single power conversion unit, it is possible to realize a high-frequency heating device that can generate a large radio wave output exceeding the allowable power of the external power supply while being simple and inexpensive. It is possible to achieve high frequency output, high-speed heating (cooking) is possible, and a safe and reliable high-frequency heating device is realized, which is suitable for modern eating habits requiring higher-speed cooking. A high frequency heating device can be provided at a relatively low price.

The direct output of the storage battery or the boosted output and the output of the full-wave rectifier circuit are supplied to the inverter circuit, and the sum output of both outputs is converted into power by a single inverter circuit. This allows the sum power to be obtained with an extremely simple configuration, and this sum power to be converted by a single inverter circuit to generate an extremely large radio wave output that is not limited to the maximum allowable power of the external power supply from the radio wave radiating section. A high frequency heating device capable of heating an object to be heated can be realized. Therefore, it is possible to realize a high-frequency heating device that can generate a large radio wave output that exceeds the allowable power of the external power supply while being simple and low-priced. The high-frequency output is large and high-speed heating is possible, and it is safe. Thus, a highly reliable high frequency heating device can be realized.

Further, the full-wave rectification means and the storage battery are connected in parallel via the rectification means, and the rectification means prevents the current from flowing from the full-wave rectification means to the storage battery side. It prevents the occurrence of inconveniences such as power factor reduction of external AC power supply and instability phenomenon due to impedance mismatch, maintains high matching, and converts the sum power into a single power converter, Therefore, it is possible to provide a high-frequency heating device capable of heating an object to be heated by generating an extremely large radio wave output that is not limited to the maximum allowable power of the external power source. Therefore, it is possible to heat the object to be heated at high speed by generating an extremely large radio wave output, which was difficult in the past due to the limitation of the external power supply capacity, and to realize a safe, reliable and long-life high-frequency heating device. It is possible to provide a high-frequency heating device that is suitable for modern dietary life that requires higher-speed cooking.

The charging means for charging the storage battery is provided, and the storage battery is charged by the electric power of the external power source, so that the storage battery can be charged safely and surely by the electric power of the external power source while repeating charging and discharging. It is possible to provide a high-frequency heating device that can easily supply the sum power of the storage battery and the power of the external power source to the power conversion unit for a long period of time while maintaining high consistency. Therefore, the storage battery can be automatically charged, and a high-frequency heating device capable of high output, which is difficult with the conventional technology, can be realized, which is suitable for the modern diet which requires higher-speed cooking. In addition, it is possible to provide a high-frequency heating device that is easy to use because it can be automatically charged.

Furthermore, the storage battery is charged by the power of the external power supply when the power conversion unit stops operating, so that the power of the external power supply is always supplied to the power conversion unit at the maximum level during operation. It is possible to realize a high-power high-frequency heating device that is difficult to achieve by the conventional technique while minimizing the discharge capacity of the storage battery. Moreover, the storage battery power can be always used while charging the storage battery during periods of non-operation (when not in use), and a large radio wave output capability suitable for modern eating habits requiring higher-speed cooking. It is possible to provide a high-frequency heating device that is capable of exhibiting the above-mentioned properties and is extremely easy to use.

[Brief description of drawings]

FIG. 1 is a block diagram of a high-frequency heating device according to an embodiment of the present invention.

FIG. 2 is a block diagram of a high frequency heating apparatus according to another embodiment of the present invention.

FIG. 3 (a) is an output voltage waveform diagram of the full-wave rectifying means of the high-frequency heating device shown in FIG. 2;

FIG. 4 is a characteristic diagram of an input power factor from a commercial power source with respect to an output voltage of a booster of the high frequency heating device of FIG.

5 (a) Supply voltage waveform diagram from the commercial power source of the high frequency heating device of FIG. 2 (b) Supply voltage waveform diagram from the booster of the high frequency heating device of FIG. 2 (c) Of the high frequency heating device of FIG. Composite supply voltage waveform diagram of commercial power source and booster output voltage (d) Anode current waveform diagram (envelope) of the magnetron of the high frequency heating device of FIG.

FIG. 6 is a more detailed circuit diagram of the high-frequency heating device shown in FIG.

FIG. 7 is a circuit diagram of a conventional high frequency heating device.

(A) Input voltage waveform diagram of a conventional high frequency heating device (b) Transistor voltage waveform diagram of a conventional high frequency heating device (c) Anode current waveform diagram (envelope) of a magnetron of a conventional high frequency heating device

FIG. 9 is a block diagram of another conventional high-frequency heating device.

[Explanation of symbols]

 31 External Power Supply 32 High Frequency Heating Device 33 Power Conversion Section 34 Radio Wave Radiation Section 37 Storage Battery 39 Charging Means 44 Backflow Prevention Means

 ─────────────────────────────────────────────────── ─── Continuation of front page (72) Inventor Makoto Shibuya 1006 Kadoma, Kadoma City, Osaka Prefecture Matsushita Electric Industrial Co., Ltd. (72) Kenji Yasui 1006 Kadoma, Kadoma City, Osaka Matsushita Electric Industrial Co., Ltd. 72) Inventor Kei Kusunoki 1006 Kadoma, Kadoma City, Osaka Prefecture, Matsushita Electric Industrial Co., Ltd.

Claims (5)

[Claims] 1. An external power supply, comprising: a power conversion unit that converts the power supplied from an external power supply; a radio wave radiation unit that receives the converted power from the power conversion unit and radiates high-frequency power to a heating chamber; and a storage battery. A high-frequency heating device configured to convert the sum power of the battery and the storage battery by the single power conversion unit and supply the power to the radio wave radiation unit. 2. The external power source is an AC power source, the power converter is configured to include a full-wave rectifier circuit and an inverter circuit, and the direct output or boosted output of the storage battery and the full-wave rectifier circuit are provided. Is supplied to the inverter circuit, and the sum output of the both outputs is converted into electric power by a single inverter circuit. 3. The full-wave rectifying means and the storage battery are connected in parallel via the rectifying means, and the rectifying means prevents a current from flowing from the full-wave rectifying means to the storage battery side. The high-frequency heating device described. 4. The high frequency heating apparatus according to claim 1, wherein charging means for charging the storage battery is provided and the storage battery is charged by the electric power of an external power source. 5. The high-frequency heating device according to claim 4, wherein the storage battery is charged by the electric power of the external AC power supply when the operation of the power conversion unit is stopped.