JPH02230688A - High frequency heating device - Google Patents

Abstract

PURPOSE:To make it possible to operate with AC power source for indoor/ outdoor common use and with DC power source by providing a first drive power source for rectifying commercial power source for driving a magnetron and a second drive power source for stepping up a DC power source with a DC-DC converter. CONSTITUTION:A device is provided with a first drive power source 16 for rectifying a commercial power source 13 to drive a magnetron 15 and with a second drive power source 18 for stepping up the DC power source with a DC-DC converter to drive a magnetron 15. As a result, a circuit for driving the magnetron 15 by applying 100V for household to the device is made of simple and light-weight structure with only a condenser and a diode. Furthermore, because the operation voltage of the magnetron is as low as several hundred volts, the drive circuit can be constituted by directly stepping up a DC voltage of a car battery or the like, also resulting in small-sized and light- weight constitution. A device cover 7 is provided with a handle 8 for carrying.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a high frequency heating device for heating foods with microwaves, and more particularly to a high frequency heating device for both indoor and outdoor use.

Conventional technology A typical conventional device of this type is a microwave oven.

This microwave oven uses a magnetron to generate microwaves. This magnetron has a high driving voltage of several kilovolts and requires a large and heavy lance. In contrast, in recent years, inverter circuit technology has been introduced to make the driving power source part high-frequency and lightweight, and the weight of the driving power source has been reduced to about one-third.

However, since the operating voltage of the magnetron is high, it is recommended that the main body of the microwave oven be grounded for double safety.

On the other hand, if there is a demand for a portable microwave oven, but considering outdoor use, it is necessary to consider a DC power source. Using inverter technology, it would be possible to create something equivalent to a household AC power source, but the addition of a drive circuit would go against portability.

Further, the conventional oscillation form of a magnetron is a so-called burst wave oscillation form, and even though it is in this oscillation form, it outputs microwaves of several hundred watts or more on average.

If this magnetron is driven with direct current, at least 2
Generates more than twice the output. However, the efficiency of the magnetron does not change even if it is driven by direct current, so if the amount of loss in the magnetron is simply calculated, it will more than double, which creates a new and important problem of how to dissipate heat.

Problems to be Solved by the Invention Considering the outdoor use of a microwave oven, it is desirable that the microwave oven be driven by direct current. On the other hand, magnetrons have conventionally been driven in a burst wave oscillation mode, and direct current driving poses another troublesome problem. Therefore, in the conventional technology, a drive circuit configuration using inverter technology is best. In this case, the low DC voltage of 12 volts or 24 volts is boosted to several kilovolts, making the drive circuit complex, large, and inefficient, making it nearly impossible to put a DC drive in a microwave oven to practical use. There was an issue.

The present invention is intended to solve such conventional problems, and aims to provide a high-frequency heating device that can be used both indoors and outdoors and can operate with either an AC power source or a DC power source.

Means for Solving the Problems In order to solve the above problems, the high frequency heating device of the present invention has the following features:
A magnetron that is installed insulated from the heating chamber and operates at a low voltage of several hundred volts, a first drive power source that rectifies commercial power to drive the magnetron, and a DC-DC converter that boosts the DC power. The magnetron is provided with a second drive power source for driving the magnetron, and a control means that shares control of the two drive power sources.

Operation According to the above-described structure, the circuit for driving the magnetron by applying household 100 volts to the device has a simple, compact and lightweight structure consisting of only a capacitor and a diode. Furthermore, since the operating voltage of a magnetron is already several hundred volts, a drive circuit structure can be constructed in which the DC voltage of an automobile battery or the like is directly boosted, and this drive circuit can also be made compact and lightweight. As a result, it is possible to provide a portable high-frequency heating device that can be used both indoors and outdoors with both AC and DC power sources.

Example Embodiments of the present invention will be described below with reference to the accompanying drawings.

In Figures 1, 2, and 3, 1 is a heating chamber that stores the object to be heated, 2 is a magnetron that operates at several hundred ports and generates microwaves to supply power to the heating chamber, and 3 is a drive power source for the magnetron. , 4 is a waveguide that guides the microwaves generated by the magnetron into the heating chamber, 5 is a door that opens and closes the front of the heating chamber, 10 is an operating section, 7 is a main unit, and 8 is a handle for carrying. . Reference numeral 9 is a door key, and by operating this key, the closed door is opened slowly and smoothly.

The waveguide 4 is a waveguide 4a to which a magnetron is attached.
It is composed of two members: a waveguide 4b and a waveguide 4b attached to a heating chamber, and each member is fitted and assembled via an insulating member 1o. The length of this fitting part is 4 times the propagation wavelength of the fitting part, which is obtained based on the in-tube wavelength of the microwave transmitted in the waveguide and the wavelength compression ratio by the insulating member.
It is made up of one-half the length. Further, reference numeral 11 denotes an insulating plate that covers the entire wall surface of the heating chamber having the opening 12 of the waveguide.

The high-frequency heating device of the present invention has the above-described configuration, which electrically insulates the magnetron and the heating chamber, so that it is possible to use an AC power source or a DC power source to drive the magnetron while maintaining the safety of the device. Can be used. Furthermore, in order to increase portability, this device has a flatter structure compared to conventional devices of this type. Therefore, depending on the size of the object to be heated, the device can be used horizontally or vertically.In order to accommodate this, the heating chamber wall where the waveguide opening is provided is entirely covered with an insulating material. can be placed stably.

The magnetron drive power source of the present invention has a structure as shown in FIG. 4 by using a structure in which the magnetron is insulated from the heating chamber and a magnetron that operates at a low voltage of several hundred volts.

A magnetron that operates at several hundred ports has an anode having 16 or more cavity resonators and a cathode arranged concentrically with the anode in the center of the anode.

In Fig. 4, 13 is a household commercial power source, 14 is a DC power source represented by a car battery, and 16 is several hundred volts).
}, 18 is the first drive power supply, and is a full-wave voltage doubler rectifier circuit that generates the voltage applied between the anode and cathode of the magnetron, and 1 is a switching circuit that generates power to heat the cathode of the magnetron. power circuit,
18 is a second driving power supply, which is a DC-DC converter circuit that boosts the DC voltage to the voltage at which the magnetron operates;
19 is D, which generates electric power to heat the magnetron cathode.
The C-DC converter circuit 2o connects the anode and cathode terminals of the magnetron to the full-wave voltage doubler rectifier circuit and the switching power supply circuit by switching switches 21 to 23 when using the device with commercial power. When heating is performed, the switch 26, which is arranged in the commercial power supply line and cuts off the power supplied to the full-wave voltage doubler rectifier circuit and the switching power supply circuit, is controlled, and the operation of the semiconductor elements that are the components of each DC-DC converter circuit is controlled. This is a control circuit that can be used for both commercial power and DC power to operate the magnetron in unison.

According to the present invention, the first drive circuit can be constructed from a simple, small and lightweight circuit consisting of only a capacitor and a diode due to the above-described drive circuit configuration. ``!f: In the second drive circuit, the magnetron is installed insulated from the heating chamber, so the voltage of the DC power supply can be directly boosted, resulting in a compact and lightweight circuit configuration.Furthermore, conventional devices of this type This eliminates the need for a DC/AC converter, which was required when driving the converter, and eliminates the conversion loss caused by this converter, making it possible to increase the efficiency of the drive power source.

In one embodiment of the present invention, a magnetron cathode heating power supply circuit is provided for each of the household power supply and the DC power supply, but a magnetron gap pole heating power supply circuit configuration may be used for both the household power supply and the DC power supply.

Effects of the Invention As described above, the high frequency heating device of the present invention provides the following effects.

(1) A portable device for both indoor and outdoor use that maintains safety by insulating the heating chamber and magnetron, and by using a magnetron that operates at a voltage of several hundreds of volts, can be driven by either household commercial power or DC power. Can be provided.

(2) Since a DC/AC converter is not required when driving with a DC power source, the efficiency of the drive power source can be increased, the output of the magnetron can be increased, and heating can be accelerated.

(3) On the other hand, since the capacity of the DC power source may be smaller than the output of the magnetron, it is possible to extend the life of batteries in automobiles and the like.

[Brief explanation of the drawing]

Fig. 1 is an external perspective view of a high-frequency heating device showing an embodiment of the present invention, Fig. 2 is a configuration diagram when looking through the power bar of the main body, Fig. 3 is a sectional view of the main parts, and Fig. 4 is It is a block diagram of the same drive power supply circuit. 1... Heating chamber, 2, 1.5... Magnetron, 3... Drive power supply, 8... Handle, 1o... Insulation Members, 16...Full-wave voltage doubler rectifier circuit (first drive power supply), 18...
DC-DC converter (second drive source), 25...
...Control circuit.

Claims (2)

[Claims] (1) a heating chamber that stores an object to be heated; a magnetron that is installed insulated from the heating chamber and operates at a low voltage that generates microwaves that are fed to the heating chamber;
a first drive power source that rectifies a commercial power source to drive the magnetron; a second drive power source that boosts a DC power source with a DC-DC converter to drive the magnetron; and a first and second drive power source. A high-frequency heating device equipped with a control means that shares control. (2) The high-frequency heating device according to claim 1, which is provided with a handle for transportation.