Dielectric heating device and dryer including same

Abstract

A dielectric heating device according to an embodiment may comprise: a power source; a load circuit; a first AC power supply unit connected to the power source; a first impedance matching inductor unit connected to the first AC power supply unit; a second AC power supply unit connected to the power source; a second impedance matching inductor unit connected to the second AC power supply unit; and an impedance matching capacitor unit having one end connected to the first impedance matching inductor unit and the second impedance matching inductor unit and the other end connected to the load circuit.

Description

A dryer comprising a dielectric heating device and a dielectric heating device

[0001] The disclosed invention relates to a dielectric heating device and a dryer for drying a drying object using the dielectric heating device.

[0002] Typically, dryers use hot air drying to dry items. Hot air drying uses indirect heating, removing moisture through heated air. This reduces efficiency and can lead to longer drying times.

[0003] To improve drying performance, methods utilizing electromagnetic waves have been attempted in dryers. One such method utilizes a dielectric heating device, which applies an electric field to the object to be dried and exploits the frictional heat loss generated by the vibration of molecules within the object. This method offers higher drying efficiency than conventional hot air drying, and because it operates at lower temperatures, it causes less damage to the object.

[0004] The dielectric heating device may include a power amplifier for providing a high-frequency electric field. At this time, since the dielectric heating device operates at a high frequency (over 10 MHz) and high power (kW class) required for drying a material, unlike RF for signaling or communication, a power amplifier capable of high-efficiency operation in a high-frequency band (e.g., a class E power amplifier) ​​is required for driving a power load.

[0005] At this time, the voltage and current limits of the elements included in the circuit may be somewhat low, and if voltage and current stress exceeding the voltage and current limits of the elements are applied to the elements, the function of the elements may deteriorate, resulting in power loss.

[0006] Therefore, parallel operation of the power system is essential, and when power amplifiers are connected in parallel to deliver power to a single load, a very large number of components are inevitably required, which can directly lead to problems such as product price and volume.

[0007] The disclosed invention relates to a dielectric heating device including a power system in which the coupling point of each power amplifier channel is modified while maintaining the conventional parallel power amplifier design method, and a dryer for drying a subject using the dielectric heating device.

[0008] A dielectric heating device according to one embodiment may include: a power source; a load circuit; a first AC power supply connected to the power source; a first impedance matching inductor unit connected to the first AC power supply; a second AC power supply connected to the power source; a second impedance matching inductor unit connected to the second power supply; and an impedance matching capacitor unit having one end connected to the first impedance matching inductor unit and the second impedance matching inductor unit, and the other end connected to the load circuit.

[0009] In one embodiment, a dryer may include: a drum; a plurality of electrodes including a first electrode and a second electrode, the plurality of electrodes applying an electric field to the inside of the drum; a power source supplying power to the plurality of electrodes; a first AC power supply connected to the power source; a first impedance matching inductor unit connected to the first AC power supply; a second AC power supply connected to the power source; a second impedance matching inductor unit connected to the second power supply; and an impedance matching capacitor unit having one end connected to the first impedance matching inductor unit and the second impedance matching inductor unit, and the other end connected to the plurality of electrodes.

[0010] One aspect of the present disclosure is that it can reduce the number of components included in a power system, thereby reducing manufacturing costs, reducing the overall volume, and also simplifying the PCB layout.

[0011] One aspect of the present disclosure is that power system stability can be secured by reducing the output power deviation of each channel for the same impedance imbalance by reducing circulating power.

[0012] The technical problems to be achieved in this document are not limited to the technical problems mentioned above, and other technical problems not mentioned can be clearly understood by a person having ordinary skill in the technical field to which the present invention belongs from the description below.

[0013] Fig. 1 is a drawing showing one embodiment of the external appearance of a dryer (1).

[0014] Figure 2 is a cross-sectional side view of one embodiment of a dryer (1).

[0015] Figure 3 is a drawing for explaining the operation of a genetic heating device (2) according to one embodiment.

[0016] Fig. 4 is a block diagram for explaining the configuration of a genetic heating device (2) according to one embodiment.

[0017] FIG. 5 is a diagram illustrating an equivalent circuit of a power amplifier channel (331) constituting a power amplifier system (330) according to one embodiment.

[0018] FIG. 6 is a diagram illustrating an equivalent circuit of a power amplifier system (330) in which a plurality of power amplifier channels (331) are connected in parallel according to one embodiment.

[0019] Fig. 7 is a diagram illustrating an equivalent circuit of the power amplifier system (330) circuit of Fig. 6.

[0020] Fig. 8 is a diagram showing an equivalent circuit of the power amplifier system (330) circuit of Fig. 7.

[0021] FIG. 9 is a diagram illustrating an equivalent circuit of a power amplifier system (330) in which a plurality of power amplifier channels (331) are connected in parallel according to another embodiment.

[0022] Fig. 10 is a diagram illustrating an equivalent circuit of the power amplifier system (330) circuit of Fig. 9.

[0023] Fig. 11 is a diagram illustrating an equivalent circuit of the power amplifier system (330) circuit of Fig. 10.

[0024] Fig. 12 is a diagram showing an equivalent circuit of the power amplifier system (330) circuit of Fig. 11.

[0025] FIG. 13 and FIG. 14 are perspective views showing a dryer having a different shape from the dryer (1) shown in FIG. 1 according to one embodiment.

[0026] Fig. 15 is a perspective view illustrating an oven (3) including a genetic heating device (2) according to one embodiment.

[0027] Fig. 16 is a drawing showing an oven (3) including a genetic heating device (2) according to one embodiment with the door open.

[0028] It should be understood that the various embodiments and terms used in this document are not intended to limit the technical features described in this document to specific embodiments, but rather to include various modifications, equivalents, or substitutes of the embodiments.

[0029] In connection with the description of the drawings, similar reference numerals may be used for similar or related components.

[0030] The singular form of a noun corresponding to an item may include one or more of said items, unless the relevant context clearly indicates otherwise.

[0031] In this document, each of the phrases "A or B", "at least one of A and B", "at least one of A or B", "A, B, or C", "at least one of A, B, and C", and "at least one of A, B, or C" may include any one of the items listed together in that phrase, or all possible combinations thereof.

[0032] The term "and / or" includes any combination of a plurality of related described elements or any one of a plurality of related described elements.

[0033] Terms such as "first," "second," or "first" or "second" may be used simply to distinguish one component from another and do not qualify the components in any other respect (e.g., importance or order).

[0034] When a component (e.g., a first component) is referred to as being "coupled" or "connected" to another component (e.g., a second component), with or without the terms "functionally" or "communicatively," it means that the component can be connected to the other component directly (e.g., wired), wirelessly, or through a third component.

[0035] The terms "include" or "have" are intended to specify the presence of a feature, number, step, operation, component, part or combination thereof described in this document, but do not preclude the presence or addition of one or more other features, numbers, steps, operations, components, parts or combinations thereof.

[0036] When a component is said to be “connected,” “coupled,” “supported,” or “in contact with” another component, this includes not only cases where the components are directly connected, coupled, supported, or in contact, but also cases where the components are indirectly connected, coupled, supported, or in contact through a third component.

[0037] When we say that a component is "on" another component, this includes not only cases where the component is in contact with the other component, but also cases where there is another component between the two components.

[0038] Below, a dryer according to various embodiments is specifically described with reference to the attached drawings.

[0039] FIG. 1 is a drawing showing an embodiment of the exterior of a dryer, and FIG. 2 is a side cross-sectional view of an embodiment of the dryer.

[0040] Referring to FIGS. 1 and 2, a dryer (1) according to one embodiment includes a main body (10) forming an exterior and a drum (20) rotatably installed within the main body (10) and containing a material to be dried (9).

[0041] The main body (10) may include a base plate (11), a front cover (12), a top cover (13), and a side / rear cover (14).

[0042] An opening (12a) is provided in the front cover (12), and the opening (12a) is opened and closed by a door (15) that is rotatably installed in the front cover (12). A cylindrical drum (20) with an open front can also be opened and closed by the door (15).

[0043] An input unit (30a, 30b) for receiving a user's control command and a display (35) for displaying various information about the operation of the dryer (1) or guiding the user's input can be placed on the top of the front cover (12).

[0044] The input unit (30a, 30b) may be provided in the form of a jog shuttle or dial so that the user can input a control command by holding and turning or pressing the input unit (30a), or may be provided in the form of a touch pad or button so that the user can input a control command by touching or pressing the input unit (30b).

[0045] The display (35) can be implemented by various display panels such as LCD, LED, OLED, and QLED, and can also be implemented as a touch screen by providing a touch pad on the front.

[0046] A front panel (21) having an inlet (21a) formed therein may be arranged on the front of the drum (20), and the drying material (9) may be fed into the drum (20) through the inlet (21a). In addition, the rear of the drum (20) may be closed by a rear panel (22) having an outlet (22a) through which high-temperature dry air is discharged.

[0047] An outlet (21b) through which air used for drying the object to be dried (9) flows out may be provided on the front panel (21) of the drum (20), and a filter (23) for capturing foreign substances generated from the object to be dried (9) may be installed on the outlet (21b).

[0048] That is, the air discharged to the drum (20) through the discharge port (22a) is used for drying the object to be dried (9) and can then be introduced from the drum (20) into the duct (50) through the outlet port (21b). The air used for drying the object to be dried (9) is converted into high-temperature dry air through the heat pump (150) after being introduced into the duct (50) and can then be discharged back to the drum (20) through the discharge port (22a).

[0049] Additionally, at least one lifter having a protruding shape may be formed on the inner wall of the drum (20) to assist in tumbling the drying material (9).

[0050] The drum (20) can rotate by driving force provided from the drum motor (25). The drum (20) is connected to the drum motor (25) by a belt (26), and the belt (26) can transmit the driving force provided from the drum motor (25) to the drum (20).

[0051] The dryer (1) may include a fan (40) that circulates air inside the drum (20). The fan (40) may suck in air from inside the drum (20) and discharge the air through a duct (50). By means of the fan (40), the air inside the drum (20) may circulate through the drum (20) and the duct (50).

[0052] A heat pump (150) may be provided on a duct (50) through which air circulates inside the drum (20). The heat pump (150) may include a compressor (not shown), a condenser (152), an evaporator (154), and an expander (not shown).

[0053] A compressor compresses gaseous refrigerant into a high-temperature, high-pressure state and discharges the compressed high-temperature, high-pressure gaseous refrigerant. For example, the compressor can compress the refrigerant through the reciprocating motion of a piston or the rotary motion of a rotor. The discharged refrigerant is delivered to a condenser (152).

[0054] The condenser (152) can release heat to the surroundings while condensing the compressed gaseous refrigerant into a liquid. The condenser (152) can be installed on the duct (50) and can heat air through the heat generated during the condensation process of the refrigerant. The heated air can be supplied to the drum (20). The liquid refrigerant condensed in the condenser (152) can be transferred to an expander (not shown).

[0055] The expander can expand the high-temperature, high-pressure liquid refrigerant condensed in the condenser (152) into a low-pressure liquid refrigerant. Specifically, the expander can include a capillary tube and an electronic expansion valve whose opening amount can be varied by an electric signal to control the pressure of the liquid refrigerant.

[0056] The evaporator (154) can evaporate the liquid refrigerant expanded in the expander. As a result, the evaporator can return the low-temperature, low-pressure gaseous refrigerant to the compressor.

[0057] The evaporator (154) can absorb heat from the surroundings through an evaporation process that changes low-pressure liquid refrigerant into gaseous refrigerant. The evaporator (154) can be installed on the duct (50) and can cool the air passing through the evaporator (154) during the evaporation process. The surrounding air is cooled by the evaporator (154), and when the temperature of the surrounding air becomes lower than the dew point, the air around the evaporator (154) can condense. The water condensed in the evaporator (154) can be collected by a water collecting tank provided at the bottom of the evaporator (154). The water collected in the water collecting tank can be moved to a separate storage or drained to the outside of the dryer (1).

[0058] As condensation occurs around the evaporator (154), the absolute humidity of the air passing through the evaporator (154) may decrease. In other words, the amount of water vapor contained in the air passing through the evaporator (154) may decrease. By utilizing this condensation around the evaporator (154), the dryer (1) can reduce the amount of water vapor contained in the air inside the drum (20) and dry the object to be dried (9).

[0059] The evaporator (154) may be located upstream of the condenser (152) based on the air flow by the fan (40). The air circulated by the fan (40) may be dried (water vapor may be condensed) by the evaporator (154) while passing through the evaporator (154), and may be heated by the condenser (152) while passing through the condenser (152).

[0060] Meanwhile, a heater (160) may be provided in the duct (50) to heat the air by assisting the condenser (152). The heater (160) may be located downstream from the condenser (152) based on the air flow by the fan (40).

[0061] For example, by additionally heating the air heated in the condenser (152) of the heat pump (150) by the heater (160), the air in the duct (50) can be sufficiently heated.

[0062] The temperature inside the drum (20) can rise more quickly by the heater (160) assisting the condenser (152), and the time required for drying the object to be dried (9) can be shortened.

[0063] A dryer (1) according to one embodiment may include a plurality of electrodes (400) protruding from the inner surface of a drum (20). A pair of electrodes (400) may include a first electrode (401) and a second electrode (402).

[0064] The first electrode (432) may be placed on the upper side of the drum (20), and the second electrode (433) may be placed on the lower side of the drum (20). The first electrode (432) and the second electrode (433) may be spaced apart from each other with the drum (20) interposed therebetween to form an electric field inside the drum (20). The electric field formed inside the drum (20) may include a high-frequency electric field.

[0065] The first electrode (401) and the second electrode (402) can be implemented using a predetermined conductive plate, and the predetermined conductive plate may include, for example, a predetermined metal plate. In this case, the metal plate may be made of zinc, aluminum, magnesium, or an alloy thereof. In addition, the predetermined conductive plate may be implemented using a ceramic material through which current can flow.

[0066] A dryer (1) according to one embodiment may include a dielectric heating device (2), which will be described below with reference to FIGS. 3 and 4.

[0067] Figure 3 is a drawing for explaining the operation of a genetic heating device (2) according to one embodiment.

[0068] A dielectric heating device (2) according to one embodiment may include a high-frequency power source (210) and a plurality of electrodes (401, 402). A high-frequency electric field (230) may be formed between the first electrode (401) and the second electrode (402) based on power provided from the high-frequency power source (210).

[0069] When an object (e.g., a drying object) located between the first electrode (401) and the second electrode (402) contains polar molecules (240) (e.g., water molecules), it can undergo rotational and / or vibrational motion by the high-frequency electric field (230). The object can be heated by the motion of the polar molecules (240) within the object.

[0070] Polar molecules (240) within an object can be located on the surface and inside of the object, and the part of the object that is heated can be determined depending on the location where the polar molecules (240) are located within the object.

[0071] According to a dielectric heating device (2) according to one embodiment, an object can be uniformly heated due to the movement of polar molecules (240) within the object.

[0072] Fig. 4 is a block diagram for explaining the configuration of a dielectric heating device (2) according to one embodiment. Referring to Fig. 4, the configuration of a dielectric heating device (2) according to the embodiment can be explained.

[0073] Referring to FIG. 4, a genetic heating device (2) according to an embodiment may include a power source (310), a load circuit (320), and a power amplifier system (330). The power amplifier system (330) may output power to the load circuit (320) using power provided from the power source (310).

[0074] The power source (310) may be an input power source or may include an input power source. The input power source may apply a driving voltage (VDD). The dielectric heating device (2) may include one power source (310) or may include multiple power sources (310).

[0075] The load circuit (320) may include a capacitor and an inductor. According to various embodiments, at least a portion of the capacitor may constitute at least a portion of the plurality of electrodes (e.g., 401, 402) of FIG. 2. Although an embodiment with two electrodes is disclosed in FIG. 2, there is no limitation on the number of electrodes for heating the object to be heated.

[0076] The fact that the load circuit (320) includes a capacitor may mean that the load circuit (320) includes electrodes for heating the object to be heated. That is, when voltage is applied to a plurality of electrodes included in the load circuit (320), the plurality of electrodes may function as a single capacitor.

[0077] The load circuit (320) may include a resistor, and according to various embodiments, the resistor may be a resistance of a conductor forming the circuit or a component included in the circuit. According to various embodiments, the resistor may be a circuit model of a heated object heated by the dielectric heating device (2).

[0078] The power amplifier system (330) can supply high power (e.g., kW class) at a high frequency (e.g., 10 MHz or more) to effectively operate the dielectric heating device (2) to dry the object located inside the electrode (400) of the load circuit (320).

[0079] That is, the power amplifier system (330) may include various configurations to ensure high power transmission amplification (i.e., the ability of the power amplifier system (330) to amplify power received from the input and stably transmit high power to the output load) of the power source (310). Hereinafter, with reference to FIG. 5, a power amplifier channel (331), which is a component unit of the power amplifier system (330), will be described.

[0080] FIG. 5 is a diagram illustrating an equivalent circuit of a power amplifier channel (331) constituting a power amplifier system (330) according to one embodiment.

[0081] A power amplifier channel (331) according to one embodiment may include an E CLASS power amplifier.

[0082] The power amplifier channel (331) may include an AC power supply unit (56), an LC resonant circuit (54), and an LC reactance matching circuit (55). At this time, the AC power supply unit (56) may include a transistor (51), an inductor (e.g., an RF (radio frequency) choke inductor (Lchk) (52)), and / or a capacitor (e.g., a shunt capacitor (Csh) (53)). The AC power supply unit (56) may configure a resonant switching cell and operate as an AC voltage source according to a switching operation.

[0083] The transistor (51) operates by receiving a driving voltage (VDD) from an input power source, and can be turned on or off by receiving an input signal (6) (or a control signal) in a pulse form (e.g., a square wave) through an input terminal (e.g., a gate). For example, the transistor (51) may include a bipolar junction transistor (BJT) or a metal oxide semiconductor field effect transistor (MOSFET). If the transistor (51) is an N-channel MOSFET (NMOS), the input signal (6) may be a gate voltage applied to the gate terminal of the N-channel MOSFET. The source of the transistor (51) may be connected to ground, and the drain may be connected to an output node (7).

[0084] The inductor included in the AC power supply unit (56) may include an RF choke inductor (52). The RF choke inductor (52) can block the transmission of an RF signal from the power source to the transistor (51) so that only DC current is transmitted to the transistor (51).

[0085] The capacitor included in the AC power supply unit (56) may include a shunt capacitor (53). The shunt capacitor (53) is connected in parallel with the transistor (51) and may be discharged or charged while the transistor (51) is turned on or off. The shunt capacitor (53) may be a separate capacitor connected in parallel with the transistor (51) and may be described as a concept including the internal capacitance of the transistor (51) (e.g., drain-source capacitance (Cds)).

[0086] Based on the transistor (51) being turned on or off according to the input signal (6), RF power can be generated, and the generated RF power can be transmitted to the series LC resonant circuit (54) through the output node (7).

[0087] More specifically, when the transistor (51) is turned on (e.g., when the transistor (51) is saturated), the transistor (51) is electrically short-circuited and can be interpreted as a short circuit to ground connected to the source, and the voltage at the output node (7) can be interpreted as 0. The current flowing to the transistor (51) through the RF choke inductor (52) can gradually increase.

[0088] Thereafter, when the transistor (51) is turned off, the current flowing through the RF choke inductor (52) is directed to the shunt capacitor (53), and as the shunt capacitor (53) is gradually charged, the voltage of the output node (7) (e.g., the voltage across the two terminals of the shunt capacitor (53)) may increase until it reaches a maximum value. Thereafter, as the shunt capacitor (53) is gradually discharged, the current flows from the shunt capacitor (53) through the output node (7) to the series LC resonant circuit (5), and the voltage of the output node (7) (e.g., the voltage across the two terminals of the shunt capacitor (53)) may gradually decrease. In the power amplifier channel (331), for high-efficiency operation (e.g., to minimize power consumed in the transistor (51)), the transistor (51), the shunt capacitor (53) and the input signal (6) may be set so that the voltage of the output node (7) (e.g., the voltage across the shunt capacitor (53) and the drain-source voltage of the transistor (51)) gradually decreases to 0 and the amount of change in the decrease in the voltage of the output node (7) becomes 0 before the transistor (51) is turned on again after it is turned off (e.g., before current starts to flow to the transistor (51) again through the RF choke inductor (52)).

[0089] Afterwards, when the transistor (51) is turned on again, the current flowing through the RF choke inductor (52) is directed to the transistor (51), and the voltage of the output node (7) can be maintained at 0 while the transistor (51) is in the on state. As described above, while the transistor (51) is in the on state, the drain-source voltage of the transistor (51) (e.g., the voltage of the output node (7)) is 0, and while the transistor (51) is in the off state, the current flowing through the RF choke inductor (52) is directed toward the shunt capacitor (53), so that the current flowing to the transistor (51) through the RF choke inductor (52) is 0 (in other words, because the period in which the drain-source voltage of the transistor (51) is non-zero and the period in which the drain-source current is non-zero do not overlap), so that the power consumed in the transistor (51) in an ideal environment is 0, and high-efficiency operation of the transistor (51) can be possible.

[0090] However, in a non-ideal environment, since the power amplifier channel (331) generates a signal (or RF power) based on whether the transistor (51) is turned on or off, the generated signal (or RF power) may include not only the desired frequency component (e.g., the fundamental component of the operating (resonant) frequency) but also second-order or higher harmonic components, and power consumption may occur in the transistor (51) due to the second-order or higher harmonic components.

[0091] The LC resonant circuit (54) may include at least one resonant inductor (Lr) and at least one resonant capacitor (Cr) connected in series with each other. The LC resonant circuit (54) may be set to have a resonant frequency corresponding to (e.g., identical to) the operating frequency of the input signal (6) so as to resonate with the operating frequency. For example, the resonant inductor (Lr) and the resonant capacitor (Cr) having inductance values ​​and capacitance values ​​such that the reactance value of the equivalent impedance of the LC resonant circuit (54) becomes 0 at the operating frequency of the input signal (6) may be designed to be included in the series LC resonant circuit (54).

[0092] In the power amplifier channel (331), based on whether the transistor (51) is turned on or off in response to the input signal (6), current may flow from the RF choke inductor (52) to the transistor (51) or the shunt capacitor (53) or from the shunt capacitor (53) to the series LC resonant circuit (54), thereby generating an alternating current (AC) current. The AC current generated through the LC resonant circuit (5) may be output to a reactance matching circuit (55) and / or a load (8), thereby generating an AC voltage in the load (8).

[0093] It can be explained that an alternating current is generated based on the above-described transistor (51) being turned on or off, and a signal (or RF power) is generated based on the transistor (51) being turned on or off.

[0094] The reactance circuit (55) is connected in series to the LC resonant circuit (54) and can provide impedance matching to match the output impedance of the power amplifier to the load (8). The reactance circuit (55) can include at least one reactance inductor (Llp) connected in series with each other and at least one reactance capacitor (Clp) connected in parallel or in series with the at least one reactance inductor (Llp). At this time, the reactance capacitor (Clp) can be omitted depending on the load condition of the load (8).

[0095] The load (8) may include at least one hardware component (e.g., circuit element) that receives or operates upon receiving a signal (or RF power) generated by the power amplifier. That is, the load (8) may be a concept that includes a load circuit.

[0096] FIG. 6 is a diagram illustrating an equivalent circuit of a power amplifier system (330) in which a plurality of power amplifier channels (331) are connected in parallel according to one embodiment.

[0097] According to one embodiment, a plurality of power amplifier channels (331) (e.g., a first channel (Ch1) and a second channel (Ch2)) may be connected in parallel to form a power amplifier system (330). Referring to FIG. 6, a power amplifier system (330) in which two power amplifier channels (331) are connected in parallel is illustrated, but the number of amplifier channels (331) that may be connected in parallel is not limited.

[0098] When each power amplifier channel (331) is connected in parallel, a node (N1) can be formed where the output from each power amplifier channel (331) is collected.

[0099] In the past, in order to increase the efficiency of power transmission and minimize power loss, the LC resonant circuit (54) that matches the input impedance of the input signal (6) and the power amplifier channel (331) and the reactance circuit (55) that matches the output impedance of the load (load (8) of FIG. 5, or load circuit (320) of FIG. 4) and the power amplifier were viewed as separate configurations, and a plurality of inductors and capacitors that constitute the LC resonant circuit (54) and the reactance circuit (55) were positioned between the supply section (65a, 65b) and the node (N1) as shown in FIG. 6.

[0100] Accordingly, the number of passive components increases significantly during the configuration of the parallel power amplifier system (330), which leads to an increase in system manufacturing cost and PCB layout volume.

[0101] In addition, as many passive components are used in the process of connecting multiple power amplifier channels (331), a problem of imbalance in the impedance of the power amplifier channel (331) occurs due to manufacturing errors in passive component parameters and parasitic components on the PCB layout.

[0102] The impedance imbalance of the power amplifier channel (331) causes a deviation in the output power of each channel even when there is no gating phase error, which causes various problems such as a decrease in system efficiency and heat generation in a specific channel, thereby lowering system stability. Therefore, it has become necessary to reduce the number of passive components and secure system stability by countering the impedance imbalance. Hereinafter, a method for modifying the coupling point of a plurality of power amplifier channels (331) to reduce the number of passive components according to one embodiment will be described with reference to FIGS. 7 and 8.

[0103] Fig. 7 is a diagram illustrating an equivalent circuit of the power amplifier system (330) of Fig. 6.

[0104] FIG. 7 is an equivalent circuit identical to the circuit illustrated in FIG. 6, and may be composed of a first AC power supply unit (56a), a second AC power supply unit (56b), a first impedance matching inductor unit (501), a second impedance matching inductor unit (502), an impedance matching capacitor unit (503), and a load circuit (Ract).

[0105] The first AC power supply unit (56a) and the second AC power supply unit (56b) can be explained as concepts corresponding to the AC power supply unit (56) of FIG. 5.

[0106] The first impedance matching inductor unit (501) and the second impedance matching inductor unit (502) are respectively connected in series with each other as a resonance inductor (Lr) of an LC resonant circuit (54) and a reactance inductor (L) of a reactance circuit (55). LP ) may be included.

[0107] At this time, the first impedance matching inductor unit (501) and the second impedance matching unit may include variable inductors. For example, the resonant inductor (Lr) or the reactance inductor (LLP) may include a variable inductor.

[0108] The total inductance of the first impedance matching inductor unit (501) and the second impedance matching inductor unit (502) may be the same or different.

[0109] The impedance matching capacitor unit (503) may include at least one resonant capacitor (Crm).

[0110] At this time, the resonant capacitor (Crm) included in the impedance matching capacitor unit (503) may be equal to the sum of the capacitances of the resonant capacitor (Cr) of the first channel (Ch1) and the resonant capacitor (Cr) of the second channel (Ch2) (i.e., Crm=2Cr).

[0111] According to various embodiments, the impedance matching capacitor unit (503) comprises at least one reactance capacitor (C LPM ) may be included.

[0112] The impedance matching capacitor unit (503) is a reactance capacitor (C) connected in parallel with the resonant capacitor (Crm) according to the load conditions of the load circuit. LPM ) can be determined.

[0113] For example, the impedance matching capacitor unit (503) is connected to a parallel capacitor (C) according to the load condition of the load circuit (Ract) connected to the impedance matching capacitor unit (503). LPm ) can be added. In addition, the impedance matching capacitor unit (503) may not include a parallel capacitor (CLPm) depending on the load condition of the load circuit (Ract) to which the impedance matching capacitor unit (503) is connected.

[0114] Also, the parallel capacitor (C) of Fig. 7 LPm ) is the reactance capacitor (C) of the first channel (Ch1). LP ) and the reactance capacitor (C) of the second channel (Ch2) LP ) can be equal to the sum of the capacitances (i.e., CLPm =2C LP ).

[0115] Fig. 8 is a diagram showing an equivalent circuit of the power amplifier system (330) circuit of Fig. 7.

[0116] Fig. 8 shows an equivalent circuit to the circuits shown in Figs. 6 and 7.

[0117] Referring to Fig. 8, the first channel and the second channel are connected in parallel with each other, with node (N1) serving as a connection point. Node (N1) of Fig. 8 corresponds to node (N1) of Figs. 6 and 7.

[0118] According to one embodiment, in the arrangement of a plurality of passive elements that perform impedance matching with an input signal (6) and a load circuit (Ract) in a power amplifier system (330), an impedance matching inductor unit (501, 502) corresponding to a plurality of series-connected inductors may be positioned in front of a node (N1), and an impedance matching capacitor unit (503) composed of at least one capacitor may be positioned in the rear of the node (N1). In this case, one end facing the AC power supply unit (56) with respect to the node (N1) may correspond to the front end, and the other end may correspond to the rear end.

[0119] Specifically, the first impedance matching inductor unit (501) may be connected between the first AC power supply unit (56a) and the node (N1), and the second impedance matching inductor unit (502) may be connected between the second AC power supply unit (56b) and the node (N1). At this time, the first impedance matching inductor unit (501) and the second impedance matching unit (503) may include a plurality of inductors connected in series with each other.

[0120] Additionally, the impedance matching capacitor unit (503) is connected between the node (N1) and the load circuit (Ract) and may include at least one series capacitor. The impedance matching capacitor unit (503) may further include a parallel capacitor depending on the load conditions of the load circuit (Ract) connected to the output terminal.

[0121] That is, based on the equivalent circuit of FIG. 6 shown in FIG. 7 and FIG. 8, in a power amplifier system (330) in which multiple power amplifier channels (331) are connected in parallel, a resonance capacitor (Cr) or a reactance capacitor (C) is provided as many as the number of channels. LP ) can be implemented with the same specifications through a single integrated series capacitor or parallel capacitor, without the need for a separate capacitor. Accordingly, the number of components can be reduced, simplifying the PCB layout and reducing the overall volume.

[0122] In addition, as shown in Fig. 8, the design method of the existing parallel power amplifier system is maintained, but by modifying the coupling point of each power amplifier channel, the transmission power imbalance of each power amplifier channel (331) can be alleviated through reduction of circulating power.

[0123] Specifically, the output current i delivered to the load in the power amplifier system (330) o can be determined as shown in Equations 1 and 2 below.

[0124] [Formula 1]

[0125] i o =1 / Z o ((jX||Z o ) / (jX+jX||Z o ))(v1+v2)

[0126] [Formula 2]

[0127] i o =Z t (v1+v2)

[0128] (At this time, i o is the output current delivered to the load circuit, jX(X) is the total impedance of the passive components located in the front end based on the node (N1), and Z o is the characteristic impedance of the passive components and load circuit (Ract) located at the rear end based on node (N1), v 1, v2 is the output voltage of the first AC voltage supply unit (65a) and the second AC voltage supply unit (56b), Z t represents the total impedance of the power amplifier system (330).

[0129] The total impedance of the power amplifier system (330) does not change by changing the parallel connection points of the multiple power amplifier channels (331).

[0130] However, when comparing the structure of the power amplifier system (330) of FIG. 6 and FIG. 8, the structure of FIG. 6 further includes a capacitor (i.e., Cr) in addition to the elements included in the first impedance matching inductor unit (501) (or the second impedance matching inductor unit (502)) of FIG. 8 between the first AC power supply unit (56a) (or the second AC power supply unit (56b)) and the node (N1). Accordingly, the value of X in FIG. 6 is as in Equation 3, and the value of X in FIG. 8 is as in Equation 4.

[0131] [Formula 3]

[0132] X=[w(Lr+LLP)-1 / wCr)]

[0133] [Formula 4]

[0134] X=w(Lr+LLP)

[0135] (At this time, Lr represents the inductance of the resonant inductor, LLP represents the inductance of the reactance inductor, w represents the resonant frequency, and Cr represents the resonant capacitor.)

[0136] Comparing the values ​​of X according to the above-described equations 3 and 4, the value of X can be increased by reducing the number of capacitors by changing the parallel connection points of multiple power amplifier channels (331).

[0137] Accordingly, it can be confirmed that the value of X increases by changing the parallel connection points of multiple power amplifier channels (331), and the circulating current decreases correspondingly.

[0138] That is, according to the circuit structure of the power amplifier system (330) according to FIG. 8, the power imbalance between each power amplifier channel (331) can be resolved by reducing the overall circulating current without changing the electrical characteristics of the entire circuit.

[0139] FIG. 9 is a diagram illustrating an equivalent circuit of a power amplifier channel (331) constituting a power amplifier system (330) according to another embodiment.

[0140] A power amplifier channel (331) according to another embodiment may include an E / F2 CLASS power amplifier.

[0141] The power amplifier channel (331) may include an AC power supply (56), an LC resonant circuit (54), and an LC reactance matching circuit (55). According to another embodiment, the AC power supply (56) may include a transistor (51), an inductor (e.g., a radio frequency (RF) choke inductor (Lchk) (52)), a capacitor (e.g., a shunt capacitor (Csh) (53)), and / or an LC resonant circuit (57).

[0142] The AC power supply unit (56) can operate as an AC voltage source according to the switching operation by configuring a resonant switching cell. At this time, if the AC power supply unit (56) further includes an LC resonant circuit (57), the LC resonant circuit (57) can be connected in parallel to the output node (7). The LC resonant circuit (57) includes at least one inductor (L h ) and at least one capacitor (C h ) may be included.

[0143] The transistor (51), the inductor (e.g., the RF choke inductor (52)), the capacitor (e.g., the shunt capacitor (53)), the LC resonant circuit (54), the reactance circuit (55) or the load (8) included in the power amplifier channel (331) according to another embodiment may include the configuration, function, structure, etc. of each of the transistor (51), the inductor (e.g., the RF choke inductor (52)), the capacitor (e.g., the shunt capacitor (53)), the LC resonant circuit (54), the reactance circuit (55) or the load (8) described above with reference to FIG. 5.

[0144] FIG. 10 is a diagram illustrating an equivalent circuit of a power amplifier system (330) in which a plurality of power amplifier channels (331) are connected in parallel according to another embodiment.

[0145] According to another embodiment, a plurality of power amplifier channels (331) (e.g., a first channel (Ch1') and a second channel (Ch2')) may be connected in parallel to form a power amplifier system (330). Although FIG. 10 illustrates a power amplifier system (330) in which two power amplifier channels (331) are connected in parallel, the number of amplifier channels (331) that may be connected in parallel is not limited.

[0146] When each power amplifier channel (331) is connected in parallel, a node (N2) can be formed where the output from each power amplifier channel (331) is collected.

[0147] As described above with reference to FIG. 6, when the node (N2) is located between the load circuit (Ract) and the capacitor (e.g., the resonant capacitor (Cr) or the resonance capacitor (Clp)), the number of passive components increases significantly during the configuration of the parallel power amplifier system (330), which may cause an increase in the system manufacturing cost and the PCB layout volume.

[0148] In addition, as many passive components are used in the process of connecting multiple power amplifier channels (331), an imbalance in the impedance of the power amplifier channel (331) may occur due to manufacturing errors in passive component parameters and parasitic components on the PCB layout.

[0149] The impedance imbalance of the power amplifier channel (331) causes a deviation in the output power of each channel even when there is no gating phase error, which causes various problems such as a decrease in system efficiency and heat generation in a specific channel, thereby lowering system stability. Therefore, it has become necessary to reduce the number of passive components and secure system stability by countering the impedance imbalance. Hereinafter, a method for modifying the coupling point of a plurality of power amplifier channels (331) to reduce the number of passive components according to one embodiment will be described with reference to FIGS. 11 and 12.

[0150] Fig. 11 is a diagram illustrating an equivalent circuit of the power amplifier system (330) circuit of Fig. 10.

[0151] Fig. 11 is an equivalent circuit identical to the circuit illustrated in Fig. 10, and may be composed of a first AC power supply unit (56c), a second AC power supply unit (56d), a first impedance matching inductor unit (501), a second impedance matching inductor unit (502), an impedance matching capacitor unit (503), and a load circuit (Ract).

[0152] The first AC power supply unit (56c) and the second AC power supply unit (56d) can be explained as concepts corresponding to the AC power supply unit (56) of FIG. 9.

[0153] The first impedance matching inductor unit (501) and the second impedance matching inductor unit (502) are respectively connected in series with each other as a resonance inductor (Lr) of an LC resonant circuit (54) and a reactance inductor (L) of a reactance circuit (55). LP ) may be included.

[0154] At this time, the first impedance matching inductor unit (501) and the second impedance matching unit may include variable inductors. For example, the resonant inductor (Lr) or the reactance inductor (LLP) may include a variable inductor.

[0155] The total inductance of the first impedance matching inductor unit (501) and the second impedance matching inductor unit (502) may be the same or different.

[0156] The impedance matching capacitor unit (503) may include at least one series capacitor (Crm).

[0157] At this time, the series capacitor (Crm) included in the impedance matching capacitor unit (503) may have a capacitance of the resonant capacitor (Crm) of FIG. 11 that is equal to the sum of the capacitances of the resonant capacitor (Cr) of the first channel (Ch1') and the resonant capacitor (Cr) of the second channel (Ch2') (i.e., Crm=2Cr).

[0158] The impedance matching capacitor unit (503) can determine the number of capacitors connected in parallel with the series capacitor (Crm) according to the load conditions of the load circuit.

[0159] For example, the impedance matching capacitor unit (503) can add the number of parallel capacitors (CLPm) according to the load conditions of the load circuit (Ract) to which the impedance matching capacitor unit (503) is connected at one end. In addition, the impedance matching capacitor unit (503) can add the number of parallel capacitors (CLPm) according to the load conditions of the load circuit (Ract) to which the impedance matching capacitor unit (503) is connected at one end. LPm ) may not be included.

[0160] Also, the parallel capacitor (C) of Fig. 11 LPm ) may be equal to the sum of the capacitances of the reactance capacitor (CLP) of the first channel (Ch1') and the reactance capacitor (CLP) of the second channel (Ch2') (i.e., CLPm = 2C LP ).

[0161] Fig. 12 is a diagram showing an equivalent circuit of the power amplifier system (330) circuit of Fig. 11.

[0162] Fig. 12 shows an equivalent circuit to the circuits shown in Figs. 10 and 11.

[0163] Referring to Fig. 12, the first channel and the second channel are connected in parallel with each other, with node (N2) serving as a connection point. Node (N2) of Fig. 12 corresponds to node (N2) of Figs. 10 and 11.

[0164] According to one embodiment, in the arrangement of a plurality of passive elements that perform impedance matching with an input signal (6) and a load circuit (Ract) in a power amplifier system (330), an impedance matching inductor unit (501, 502) composed of a plurality of series inductors may be positioned in front of a node (N2), and an impedance matching capacitor unit (503) composed of at least one capacitor may be positioned in the rear of the node (N2). In this case, one end facing the AC power supply unit (56) with respect to the node (N2) may correspond to the front end, and the other end may correspond to the rear end.

[0165] Specifically, the first impedance matching inductor unit (501) may be connected between the first AC power supply unit (56c) and the node (N2), and the second impedance matching inductor unit (502) may be connected between the second AC power supply unit (56d) and the node (N2). At this time, the first impedance matching inductor unit (501) and the second impedance matching inductor unit (502) may include a plurality of inductors connected in series with each other.

[0166] Additionally, the impedance matching capacitor unit (503) is connected between the node (N2) and the load circuit (Ract) and may include at least one series capacitor. The impedance matching capacitor unit (503) may further include a parallel capacitor depending on the load conditions of the load circuit (Ract) connected to the output terminal.

[0167] That is, based on the equivalent circuit of FIG. 10 illustrated in FIGS. 11 and 12, in a power amplifier system (330) in which a plurality of power amplifier channels (331) are connected in parallel, the same specifications can be implemented through a single integrated series capacitor or parallel capacitor without having to provide as many resonant capacitors (Cr) or reactance capacitors (CLP) as the number of channels. Accordingly, the number of components can be reduced, simplifying the PCB layout and reducing the overall volume.

[0168] In addition, as shown in Fig. 12, the design method of the existing parallel power amplifier system is maintained, but by modifying the coupling point of each power amplifier channel, the transmission power imbalance of each power amplifier channel (331) can be alleviated through reduction of circulating power.

[0169] According to another embodiment, the power amplifier channel (331) is connected in parallel to the power amplifier system (330), and the output current i is delivered to the load. o It can also be determined by Equations 1 and 2 described with reference to Fig. 8.

[0170] In addition, when comparing the structures of the power amplifier systems (330) of FIGS. 10 and 12, the structure of FIG. 10 further includes a capacitor (i.e., Cr) in addition to the elements included in the first impedance matching inductor unit (501) (or the second impedance matching inductor unit (502)) of FIG. 12 between the first AC power supply unit (56c) (or the second AC power supply unit (56d)) and the node (N2). Accordingly, the value of X in FIG. 10 is the same as Equation 3 described with reference to FIG. 8, and the value of X in FIG. 8 is the same as Equation 4 described with reference to FIG. 8.

[0171] As described above, comparing the values ​​of X according to Equations 3 and 4, the value of X can be increased by reducing the number of capacitors by changing the parallel connection points of multiple power amplifier channels (331).

[0172] Accordingly, it can be confirmed that the value of X increases by changing the parallel connection points of multiple power amplifier channels (331), and the circulating current decreases correspondingly.

[0173] That is, according to the circuit structure of the power amplifier system (330) according to Fig. 12, the power imbalance between each power amplifier channel (331) can be resolved by reducing the overall circulating current without changing the electrical characteristics of the entire circuit.

[0174] FIG. 12 and FIG. 13 are perspective views showing a dryer having a different shape from the dryer (1) shown in FIG. 1 according to one embodiment.

[0175] Referring to FIG. 12, a dryer according to one embodiment may include a main body forming an exterior and a chamber installed inside the main body, where drying of a drying material (9) takes place. The main body forms the exterior of the dryer and may be provided in a hexahedral shape. An opening may be formed at the front of the main body through which a drying material (9) may be introduced.

[0176] The dryer (1) according to the present embodiment may include a dielectric heating device (2).

[0177] The genetic heating device (2) according to the present embodiment may include a power amplifier system (330) implemented in a structure in which a plurality of power amplifier channels (331) are connected in parallel as described above.

[0178] At this time, in the arrangement of a plurality of passive elements that perform impedance matching with the input signal (6) and the load circuit (Ract), an impedance matching inductor unit (501, 502) composed of a plurality of series inductors may be positioned in front of the node (N1), and an impedance matching capacitor unit (503) composed of at least one capacitor may be positioned in the rear of the node (N1). At this time, as described above, one end facing the AC power supply unit (56) with respect to the node (N1) may correspond to the front end, and the other end may correspond to the rear end.

[0179] In addition, a portion of a load circuit (320) including a plurality of electrodes (e.g., the first electrode (401) and the second electrode (402) of FIG. 2) may be implemented in a protruding form on the inner surface of the chamber of the dryer (1). The load circuit (320) according to the present embodiment may include the functions, configurations, etc. described above.

[0180] The first electrode (401) and the second electrode (402) are spaced apart from each other so that the object to be dried (9) can be positioned between the first electrode (401) and the second electrode (402).

[0181] Referring to FIG. 13, a dryer according to one embodiment may include a function for drying shoes. For example, the object to be dried (9) may include not only clothing but also shoes (e.g., shoes, sneakers, slippers, etc.).

[0182] A dryer according to the present embodiment may include a main body constituting an outer surface, and the main body may include a door provided on the front side and opened and closed to allow shoes to enter and exit, a left side plate constituting a left side, a right side plate constituting a right side, a rear plate constituting a rear side, an upper plate constituting an upper surface, and a bottom plate constituting a bottom surface.

[0183] The dryer according to the present embodiment may include a shoe receiving section for receiving the object to be dried (9), and a plurality of shoe receiving sections may be provided.

[0184] The dryer (1) according to the present embodiment may include a dielectric heating device (2). At this time, the dielectric heating device (2) may include the functions, structures, and configurations described above.

[0185] Accordingly, a portion of a load circuit (320) including a plurality of electrodes (e.g., the first electrode (401) and the second electrode (402) of FIG. 2) may be implemented in a protruding form on the inner surface of the chamber of the dryer (1). The load circuit (320) according to the present embodiment may include the functions, configurations, etc. described above.

[0186] For example, the electrode (400) according to the present embodiment may include a first electrode (401) and a second electrode (402) corresponding to each shoe receiving portion, and a high-frequency electric field may be applied between the first electrode (401) and the second electrode (402) to dry the object to be dried (9).

[0187] Fig. 14 is a perspective view illustrating an oven (3) including a genetic heating device (2) according to one embodiment.

[0188] Fig. 15 is a drawing showing an oven (3) including a genetic heating device (2) according to one embodiment with the door open.

[0189] When a high-frequency electric field is applied to the food (9a), the moisture contained in the food (9a) can function as a dielectric. Accordingly, polar molecules, such as water molecules, within the food (9a) exposed to the electric field vibrate, and heat is generated due to the vibration of the polar molecules, thereby heating the food (9a). A detailed description of this will be described with reference to FIGS. 14 and 15.

[0190] Referring to FIGS. 14 and 15, an oven (3) according to one embodiment may include a main body having a cooking chamber located inside and a cooktop provided on the top of the main body on which a container containing food (9a) can be placed and heated.

[0191] The main body according to the present embodiment may include a front panel forming the front of the main body, a side panel forming the side of the main body, and a rear panel forming the rear of the main body.

[0192] The cooking chamber according to this embodiment is provided in a box shape inside the main body and can be opened at the front to allow the loading and unloading of food (9a). An opening corresponding to the cooking chamber with the open front may be provided at the front panel. The open front of the cooking chamber can be opened and closed by a door.

[0193] A plurality of supports may be provided within the cooking chamber according to the present embodiment. The plurality of supports may be equipped with racks for placing food (9a). The plurality of supports may be provided to protrude from the left and right walls of the cooking chamber.

[0194] The oven according to the present embodiment may include an electrode (400). The electrode (400) according to the present embodiment may include the functions, configurations, etc. described above.

[0195] An opening can be formed in the front through which a dry material (9) can be injected.

[0196] The oven (3) according to the present embodiment may include a dielectric heating device (2).

[0197] The genetic heating device (2) according to the present embodiment may include a power amplifier system (330) implemented in a structure in which a plurality of power amplifier channels (331) are connected in parallel as described above.

[0198] At this time, in the arrangement of a plurality of passive elements that perform impedance matching with the input signal (6) and the load circuit (Ract), an impedance matching inductor unit (501, 502) composed of a plurality of series inductors may be positioned in front of the node (N1), and an impedance matching capacitor unit (503) composed of at least one capacitor may be positioned in the rear of the node (N1). At this time, as described above, one end facing the AC power supply unit (56) with respect to the node (N1) may correspond to the front end, and the other end may correspond to the rear end.

[0199] In addition, a portion of a load circuit (320) including a plurality of electrodes (e.g., the first electrode (401) and the second electrode (402) of FIG. 2) may be implemented in a protruding form on the inner surface of the cooking chamber of the oven (3). The load circuit (320) according to the present embodiment may include the functions, configurations, etc. described above.

[0200] The first electrode (401) and the second electrode (402) are spaced apart from each other so that the object to be dried (9) can be positioned between the first electrode (401) and the second electrode (402).

[0201] A dielectric heating device (2) according to one embodiment may include: a power source (310); a load circuit (320); a first AC power supply unit (56a) connected to the power source (310); a first impedance matching inductor unit (501) connected to the first AC power supply unit (56a); a second AC power supply unit (56b) connected to the power source (310); a second impedance matching inductor unit (502) connected to the second AC power supply unit (56b); and an impedance matching capacitor unit (503) having one end connected to the first impedance matching inductor unit (501) and the second impedance matching inductor unit (502), and the other end connected to the load circuit (320).

[0202] The above impedance matching capacitor unit (503) may include at least one resonant capacitor connected in series with the load circuit (320).

[0203] The above impedance matching capacitor unit (503) may further include at least one reactance capacitor connected in parallel with the resonant capacitor based on the load conditions of the load circuit (320).

[0204] The first AC power supply unit (56a) and the second AC power supply unit (56b) may include a transistor that is turned on or off according to an input signal, an inductor connected between the transistor and the power source, and a capacitor connected in parallel with the transistor.

[0205] The inductor connected between the transistor and the power source may be a choke inductor.

[0206] The capacitor connected in parallel with the above transistor may be a shunt capacitor.

[0207] The first AC power supply unit (56a) and the second AC power supply unit (56b) may further include an LC resonant circuit connected in parallel with the transistor.

[0208] The first impedance matching inductor unit (501) or the second impedance matching inductor unit (502) may include a resonant inductor and a reactance inductor that are connected in series with each other.

[0209] The first impedance matching inductor unit (501) or the second impedance matching inductor unit (502) may include a variable inductor.

[0210] The inductances of the first impedance matching inductor unit (501) and the second impedance matching inductor unit (502) may be the same.

[0211] A dryer (1) according to one embodiment may include: a drum (20); a plurality of electrodes including a first electrode (401) and a second electrode (402) and applying an electric field to the inside of the drum; a power source (310) supplying power to the plurality of electrodes; a first AC power supply unit (56a) connected to the power source (310); a first impedance matching inductor unit (501) connected to the first AC power supply unit (56a); a second AC power supply unit (56b) connected to the power source (310); a second impedance matching inductor unit (502) connected to the second AC power supply unit (56b); and an impedance matching capacitor unit (503) having one end connected to the first impedance matching inductor unit (501) and the second impedance matching inductor unit (502), and the other end connected to the plurality of electrodes.

[0212] The above impedance matching capacitor unit (503) may include at least one resonant capacitor connected in series with the plurality of electrodes.

[0213] The above impedance matching capacitor unit (503) may further include at least one reactance capacitor connected in parallel with the resonant capacitor based on the load conditions of the plurality of electrodes.

[0214] The first AC power supply unit (56a) and the second AC power supply unit (56b) may include a transistor that is turned on or off according to an input signal, an inductor connected between the transistor and the power source, and a capacitor connected in parallel with the transistor.

[0215] The inductor connected between the transistor and the power source may be a choke inductor.

[0216] The capacitor connected in parallel with the above transistor may be a shunt capacitor.

[0217] The first AC power supply unit (56a) and the second AC power supply unit (56b) may further include an LC resonant circuit connected in parallel with the transistor.

[0218] The first impedance matching inductor unit (501) or the second impedance matching inductor unit (502) may include a resonant inductor and a reactance inductor that are connected in series with each other.

[0219] The first impedance matching inductor unit (501) or the second impedance matching inductor unit (502) may include a variable inductor.

[0220] The inductances of the first impedance matching inductor unit (501) and the second impedance matching inductor unit (502) may be the same.

[0221] Meanwhile, the disclosed embodiments may be implemented in the form of a recording medium storing computer-executable instructions. The instructions may be stored in the form of program code, and when executed by a processor, may generate program modules to perform the operations of the disclosed embodiments. The recording medium may be implemented as a computer-readable recording medium.

[0222] Computer-readable storage media include all types of storage media that store instructions that can be deciphered by a computer. Examples include read-only memory (ROM), random access memory (RAM), magnetic tape, magnetic disks, flash memory, and optical data storage devices.

[0223] Additionally, a computer-readable recording medium may be provided in the form of a non-transitory storage medium. Here, the term "non-transitory storage medium" simply means a tangible device that does not contain signals (e.g., electromagnetic waves). This term does not distinguish between cases where data is permanently stored in the storage medium and cases where data is temporarily stored. For example, a "non-transitory storage medium" may include a buffer in which data is temporarily stored.

[0224] According to one embodiment, the method according to various embodiments disclosed in the present document may be provided as included in a computer program product. The computer program product may be traded as a product between a seller and a buyer. The computer program product may be distributed in the form of a machine-readable recording medium (e.g., compact disc read only memory (CD-ROM)), or may be distributed online (e.g., downloaded or uploaded) via an application store (e.g., Play Store™) or directly between two user devices (e.g., smartphones). In the case of online distribution, at least a portion of the computer program product (e.g., a downloadable app) may be temporarily stored or temporarily generated on a machine-readable recording medium, such as the memory of a manufacturer's server, an application store's server, or an intermediary server.

[0225] The disclosed embodiments have been described with reference to the attached drawings as described above. Those skilled in the art will understand that the present invention can be implemented in forms other than the disclosed embodiments without altering the technical spirit or essential features of the present invention. The disclosed embodiments are illustrative and should not be construed as limiting.

Claims

1. Power source; load circuit; A first AC power supply unit connected to the above power source; A first impedance matching inductor unit connected to the first AC power supply unit; A second AC power supply unit connected to the above power source; A second impedance matching inductor unit connected to the second AC power supply unit; and A dielectric heating device comprising an impedance matching capacitor unit, one end of which is connected to the first impedance matching inductor unit and the second impedance matching inductor unit, and the other end of which is connected to the load circuit.

2. In paragraph 1, The above impedance matching capacitor unit, A dielectric heating device comprising at least one resonant capacitor connected in series with the load circuit.

3. In paragraph 2, The above impedance matching capacitor unit, A dielectric heating device further comprising at least one reactance capacitor connected in parallel with the resonant capacitor based on the load conditions of the load circuit.

4. In paragraph 1, The above first AC power supply unit and the above second AC power supply unit, A dielectric heating device comprising a transistor that turns on or off depending on an input signal, an inductor connected between the transistor and the power source, and a capacitor connected in parallel with the transistor.

5. In paragraph 4, A dielectric heating device wherein the inductor connected between the transistor and the power source is a choke inductor.

6. In paragraph 4, A dielectric heating device in which a capacitor connected in parallel with the above transistor is a shunt capacitor.

7. In paragraph 4, The above first AC power supply unit and the above second AC power supply unit, A dielectric heating device further comprising an LC resonant circuit connected in parallel with the above transistor.

8. In paragraph 1, The first impedance matching inductor unit or the second impedance matching inductor unit, A dielectric heating device comprising a resonant inductor and a reactance inductor connected in series with each other.

9. In paragraph 1, The first impedance matching inductor unit or the second impedance matching inductor unit, A dielectric heating device comprising a variable inductor.

10. In paragraph 1, A dielectric heating device in which the inductances of the first impedance matching inductor unit and the second impedance matching inductor unit are the same.

11. Drums; A plurality of electrodes including a first electrode and a second electrode, and applying an electric field to the inside of the drum; A power source for supplying power to the plurality of electrodes; A first AC power supply unit connected to the above power source; A first impedance matching inductor unit connected to the first AC power supply unit; A second AC power supply unit connected to the above power source; A second impedance matching inductor unit connected to the second AC power supply unit; A dryer comprising an impedance matching capacitor unit, one end of which is connected to the first impedance matching inductor unit and the second impedance matching inductor unit, and the other end of which is connected to the plurality of electrodes.

12. In paragraph 11, The above impedance matching capacitor unit, A dryer comprising at least one resonant capacitor connected in series with the plurality of electrodes.

13. In paragraph 12, The above impedance matching capacitor unit, A dryer further comprising at least one reactance capacitor connected in parallel with the resonant capacitor based on the load conditions of the plurality of electrodes.

14. In paragraph 11, The above first AC power supply unit and the above second AC power supply unit, A dryer comprising a transistor that turns on or off depending on an input signal, an inductor connected between the transistor and the power source, and a capacitor connected in parallel with the transistor.

15. In paragraph 14, A dryer in which the inductor connected between the above transistor and the above power source is a choke inductor.

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