JPH02306573A - Ac-dc microwave oven - Google Patents

Abstract

PURPOSE:To selectively use ac and dc power by providing a first primary coil to which an ac voltage is supplied from an ac power, and a second primary coil to which a dc voltage converted by an inverter from a dc voltage applied from a battery power source is supplied, and the secondary coil of a magnetron. CONSTITUTION:When an AC-DC microwave oven is driven by an ac power, a switch S1 is turned on and a 1-1 switch S2 is turned off. Then an ac voltage is applied to the primary coil 11 of a transformer, and a high voltage induced at a second secondary coil 1-4 is doubled and rectified so that a magnetron 2 is driven. When the microwave oven is driven by a dc power using a battery 4, the switch S1 is turned off and the switch S2 is turned on, and an ac voltage is applied to the second primary coil 1-2 of the transformer 1 via an inverter 3, and a high voltage induced at the second secondary coil 1-4 is doubled and rectified so that the magnetron 2 is driven. Thus the dc or ac power is selective ly used.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention provides an AC/DC dual use microwave oven, particularly an AC/DC dual use microwave oven equipped with a magnetron that outputs high frequency energy, which includes an inverter driven from a battery power source. The first part is supplied with AC voltage from an AC power supply.
a second primary winding to which an alternating current voltage obtained by converting the direct current voltage from the battery power supply by the inverter is supplied, and a secondary winding connected to the magnetron. The present invention relates to an AC/DC microwave oven configured to be able to operate from either the AC power source or the battery power source via the transformer.

[Conventional technology]

In recent years, microwave ovens for cooking have become popular not only for commercial use but also for home use. Microwave ovens are also effective for cooking during leisure activities using croup or camping cars. Therefore, since these large leisure cruisers and camping cars are equipped with relatively large capacity batteries, AC/DC dual-purpose microwave ovens have also appeared that can be used with either commercial AC power or battery power. .

FIG. 3 is a basic configuration diagram when a microwave oven is configured to be able to operate on either alternating current or direct current, and is a configuration diagram considered as a premise of the present invention. Hereinafter, FIG. 3 will be referred to as a prerequisite configuration example for convenience. In FIG. 3, the existing (i.e. built-in)
The output of the transformer 32 for battery power supply is connected to the transformer 31 for AC power supply on the secondary side, and an inverter 33 for converting DC voltage to AC voltage is provided, and power is supplied to a magnetron 34 that outputs high frequency energy. supply.

Note that S is a switch for switching the power supply. That is, by separately providing a transformer 31 for AC power and a transformer 32 for battery power, and switching the switch S, when using AC power, the magnetron 34 is connected to the magnetron 34 via the built-in transformer 31. When a battery power source is used, the high voltage is supplied to the magnetron 34 via the separately installed transformer 32.

[Problem to be solved by the invention]

The prerequisite configuration example described above has the following undesirable problems. That is, in the prerequisite configuration example shown in FIG. 3, a transformer 31 for AC power and a transformer 32 for battery power are separately provided as high voltage transformers for transforming the voltage supplied to the magnetron 34. . Therefore, the installation space for the transformer becomes large, and the weight also becomes large, resulting in large size and high cost.

■ Of course, in order to solve this problem, instead of the prerequisite configuration example shown in Figure 3, a battery power supply is used to generate an AC voltage with the same voltage and frequency as the commercial power supply, and the system is driven by Hanoteri. It is conceivable to provide a converter with a built-in transformer 31 and connect an existing microwave oven (with a built-in transformer 31) to the output of the converter. However, this method requires a commercial frequency high power converter.

[Means to solve the problem]

The present invention aims to solve the above-mentioned problems by modifying the built-in transformer of an existing microwave oven.Therefore, the AC/DC microwave oven of the present invention has a magnetron that outputs high frequency energy. The AC/DC microwave oven is equipped with an inverter that converts the DC voltage of the battery into AC voltage, and a first primary winding to which the AC voltage from the AC power supply is supplied, and a DC voltage from the battery power supply to the inverter. A transformer is provided, the transformer having a second primary winding to which an AC voltage converted by the AC voltage is supplied and a secondary winding connected to the magnetron, and the AC voltage is supplied to the magnetron via the transformer. The device is characterized in that it is configured to selectively supply input from a power source and a battery power source.

A first battery monitor monitors the voltage of the battery and stops supplying voltage to the second primary winding when the voltage of the battery falls below a predetermined threshold; and a first battery monitor detects the temperature of the battery. The present invention is characterized in that it includes a second battery monitor that stops supplying voltage to the second primary winding when the temperature of the battery and the voltage of the battery exceed a predetermined threshold.

Hereinafter, the present invention will be described in detail with reference to the drawings.

〔Example〕

FIG. 1 is a basic configuration diagram of an embodiment of the present invention, and FIG. 2 is a circuit diagram of a battery monitor according to the present invention.

In Fig. 1, numeral 1 in the figure is a transformer, 1-1 is a first
1-2 is the second primary winding, 1-3 is the 16th primary winding.
Secondary winding, 1-4 is the second secondary winding, 1-5 is the current transformer,
2 is magnetron, 3 is inverter, 4 is battery, 5
6 is a control unit, 6 is a fan, 7 is an indicator light, 8 is a geared motor, 9 is an outlet, and Sl to S3 are switches.

The embodiment shown in FIG. 1 is a microwave oven that can be driven from either an AC power source or a DC power source using a battery 4 by operating switches S1 and S2. That is, when driven by an AC power source, the switch S
By turning on the switch S1 and turning off the switch S2, an AC voltage is applied to the first primary winding 1-1 of the transformer 1, and an AC voltage is induced in the second secondary winding 1-4. The magnetron 2 is driven by voltage double rectification of the high voltage.

In addition, when using the battery 4 as a power source or driving by a C power source, by turning off the switch SI and turning on the switch S2, the second primary winding of the transformer 1 is connected via the inverter 3. 1-2, an AC voltage is applied to the second
The magnetron 2 is driven by voltage-doubling rectification of the high voltage induced in the secondary winding 1-4. Note that the first secondary winding 1
-3 supplies a heater current to the magnetron 2. Further, the switch S3 is controlled by a battery monitor, which will be described later, which is provided to prevent the battery 4 from becoming over-discharged.

Even when driven by a DC power source, the first primary winding 1
-1 The AC voltage equivalent to the commercial voltage induced in the fan 6° indicator light 7 attached to the microwave oven. The geared motor 8 and the like for driving the turntable are driven, and the AC voltage is also supplied to the outlet 9. In addition, when driven by an AC power source, the above-mentioned fan 6, indicator light 7. Needless to say, the geared motor 8 and the like for driving the turntable are driven, and the AC power is also supplied to the outlet 9. Further, the current transformer 1-5 is provided to perform control corresponding to the load current.

In this way, since the transformer 1 that generates the high voltage supplied to the magnetron 2 is integrated into one, there are two transformers, one for AC power and one for DC power. The size of the transformer is about 2/3 compared to the prerequisite configuration example (shown in FIG. 3).

Further, in the embodiment shown in FIG. 1, when the battery 4 is driven by a DC power source, consideration must be given to prevent the battery 4 from becoming over-discharged. For this reason, the present invention is provided with a battery monitor as shown in FIG. In FIG. 2, reference numeral 10 represents a battery monitor control unit, 11 an amplifier, 12 a comparator, 13 a transistor, 14 a diode, 15 an excitation coil for the switch S3, 1°6 a temperature sensor, and other elements. The symbols correspond to those in FIG.

In the present invention, as a means to prevent the battery 4 from becoming over-discharged, a first method is adopted which monitors the terminal voltage of the battery 4 and stops power supply to the load when the terminal voltage falls below a predetermined threshold. and a second device that detects the battery voltage and the temperature of the battery 4 and stops power supply to the load when the temperature becomes equal to or higher than a predetermined threshold.
It has the means of These controls are performed by a battery monitor control section 10 provided in the control section 5.

In FIG. 2, when the terminal voltage of the battery 4 is within a normal range and when the temperature of the battery 4 is within a normal range, the output of the comparator 12 is at a high level. Therefore, the transistor 13 is kept on, the excitation coil 15 is energized, and the switch S3 is kept on. However, when the terminal voltage of the transistor 4 falls below a predetermined threshold, the output of the comparator 12 becomes low level, and the transistor 13 is turned off. As a result, the excitation coil 15 is deenergized, the switch S3 is turned off, and power supply to the inverter 3 is stopped.

Further, the level of the (-) terminal of the comparator 12 is changed via the amplifier 11 depending on the detected temperature, and the voltage threshold is changed depending on the temperature.

Note that the heater current for the magnetron 2 is, for example, 5
Whether it's a QHZ alternating current or a 100H2 alternating current, it won't have that much of an effect. Taking this into consideration, by switching the voltage doubler rectifier capacitor C shown in Figure 1 between 50 Hz operation and 100 Hz operation, an alternating current voltage of 100 Hz, for example, can be generated in the case of horizontal drive. In this way, the configuration of the inverter 3 and the configuration of the second primary winding 1-2 can be miniaturized (of course, in this case, the illustrated elements 6, 7° 8
．． 9 requires measures to prevent the frequency from switching...).

〔Effect of the invention〕

As explained above, according to the present invention, by simply modifying the high-voltage transformer that transforms the supply voltage to the magnetron, the installation space for the transformer can be reduced, and the size and size can be reduced.
It becomes possible to reduce the weight and reduce costs. Further, it is possible to prevent the battery from becoming over-discharged by simple means such as monitoring the terminal voltage of the battery and detecting the temperature of the battery.

[Brief explanation of drawings]

Fig. 1 is a basic configuration diagram of an embodiment of the present invention;
FIG. 3 shows a circuit configuration diagram of a hasoteri monitor according to the present invention, and FIG. 3 shows an example of the basic configuration of an AC/DC microwave oven considered as a premise of the present invention. In the figure, 1 is the transformer, 1-1 is the first primary winding, 1-2 is the second primary winding, 1-3 is the first secondary winding, and 1-4 is the second secondary winding, 1-5 is current transformer, 2 is magnet 1-ron,
3 is an inverter, 4 is a battery, 5 is a control unit, 6 is a fan, 7 is an indicator light, 8 is a geared motor, 9 is a power outlet I
・, 10 is a hasoteri monitor control unit, 11 is an amplifier, 12
is a comparator, 13 is a transistor, 14 is a diode, 1
5 represents an excitation coil, and 16 represents a temperature sensor.

Claims (3)

[Claims] (1) An AC/DC microwave oven equipped with a magnetron that outputs high-frequency energy is equipped with an inverter that converts the DC voltage of the battery into AC voltage, and a first primary winding that is supplied with AC voltage from the AC power source. and a transformer having a second primary winding to which an alternating current voltage obtained by converting the direct current voltage from the battery power supply by the inverter is supplied, and a secondary winding connected to the magnetron, An AC/DC microwave oven characterized in that the AC/DC microwave oven is configured to selectively supply input from the AC power source and the battery power source to the magnetron through the AC power source and the battery power source. (2) In claim (1), the first battery monitors the voltage of the battery and stops supplying voltage to the second primary winding when the voltage of the battery is equal to or less than a predetermined threshold. An AC/DC microwave oven characterized by being equipped with a monitor. (3) In claim (2), the second primary winding detects the temperature of the battery and stops supplying voltage to the second primary winding when the temperature of the battery is equal to or higher than a predetermined threshold. An AC/DC microwave oven characterized by being equipped with a battery monitor.