MXPA99000456A - Microwave oven of the type of current alternate / current dire - Google Patents

Abstract

An AC / DC type microwave oven is described, the CA / CD type microwave oven comprises a rotatable inverter which inverts a DC power source into an AC power source by means of a rotating force, a high-voltage transformer that receives a common power source or an inverted AC power by the inverter rotatable and produces a higher voltage, and a magnetron that is powered by the high voltage produced from the high-voltage transformer and radiates a microwave; further comprises a control unit that controls the operation of the rotatable inverter to produce a stable frequency, the rotatable inverter comprises a motor, a commutator driven by the motor and a plurality of brushes that are respectively in contact with an outer surface of the commutator; therefore, the manufacturing cost is reduced, the friction velocity of the current is reduced, the loss of energy by heat is also reduced, the or the microwave oven can be smaller, and the output frequency of the inverter turnable can be controlled to be kept constant, and the microwaves are radiated also more establemen

Description

MICROWAVE OVEN OF THE ALTERNATE CURRENT / DIRECT CURRENT TYPE BACKGROUND OF THE INVENTION FIELD OF THE INVENTION The present invention relates to a microwave oven, and more particularly to a microwave oven of the CA / CD type which can be used with AC / DC power sources.

DESCRIPTION OF THE PREVIOUS TECHNIQUE Generally, a microwave oven is a device used to cook food through the use of microwaves. The microwave oven is equipped with a high-voltage transformer and a magnetron. The high-voltage transformer serves to raise a common voltage of about 220V / 110V to a high voltage of about 2.0OOV to about 4.0OOV. The magnetron is powered by high voltage and microwave radiations of a desired frequency. Microwaves vibrate the moisture molecules contained within the food. Therefore, the food is cooked by the heat of friction generated by the vibration of the moisture molecules. Here, the high-voltage transformer receives an AC voltage by an input portion thereof, and increases or decreases the AC input voltage proportional to a rotational ratio of a primary winding and a secondary winding thereof. The AC voltage that is increased or decreased, is fed to an output part of the transformer. Typically, the conventional microwave oven described above is designed to be powered by an AC power source. Figure 1 is a circuit diagram showing the conventional microwave oven using the AC power source. In Figure 1, a reference number 10 denotes a high voltage transformer, 11 is a primary coil, 12 is a first secondary coil, and 13 is a second secondary coil. The primary coil 11 is wound on the input portion of the high voltage transformer 10. The first and second secondary coils 12 and 13 are wound on the output part of the high voltage transformer 10. The primary coil 11 is connected to a source of AC power SW1 is a power switch. The power switch SW1 is located on a connection cable that is disposed between the primary coil 11 and the AC power source, and connects or disconnects the primary coil 11 with the AC power source. A high voltage capacitor HVC, a high voltage diode HVD and a magnetron MGT, are connected to the output part of the transformer 10. The first secondary coil 12 preheats the magnetron MGT, and the second secondary coil 13 increases the voltage provided by the AC power source up to a voltage of approximately 2000V. The second secondary coil 13 is connected to a magnetron by the high voltage capacitor HVC and the high voltage diode HVD. The high voltage capacitor HVC and the high voltage diode HVD are a voltage duplicator that further increases the voltage raised by the second secondary coil 13 to a voltage of approximately 4.0OOV. Magnetron MGT is powered by the 4000V voltage, and radiates a microwave of 2,450MHz. The operation of the conventional microwave oven described above is described below: if a user turns on the power switch SW1, the AC voltage is supplied to the high voltage transformer 10 by the power switch SW1. In the high voltage transformer 10, the AC input voltage is fed to the primary coil 11 of the input part, and then induced to the first and second secondary coils 12 and 13 of the output part. The first secondary coil 12 preheats the magnetron MGT, and the second secondary coil 13 increases the input AC voltage fed to the input part of the primary coil 11 to approximately 2000V. The AC output voltage of approximately 2,000V, which is raised by the second secondary coil 13, is doubled by the HVC high voltage capacitor and the HVD high voltage diode, and is then applied to the MGT magnetron. Therefore, the MGT magnetron is driven by the AC output voltage of approximately 4,000V, and radiates a microwave of 2,450MHz. The food contained within a cooking chamber (not shown) is cooked by the microwaves radiated by the MGT magnetron. 5 However, since the conventional microwave oven is designed to be powered by the common 220V / 110V AC power source, there is a problem that the conventional microwave oven can not be used outdoors or on a ship , an airplane or any other vehicle.

To overcome the above problem, another conventional microwave oven is proposed which, when the microwave oven is used in a place where there is no AC power source, an inverter using a separate semiconductor device can be connected to the microwave oven, so of inverting a DC power source into an AC power source, or the inverter is arranged in the microwave oven itself. "Figure 2 is a circuit diagram of a conventional microwave oven, and Figure 3 is a diagram of inverter circuit that uses a semiconductor device. In Figure 2, the construction of the part of the AC power source is the same as that of Figure 1, and in the part of the DC power source, the inverter 20 is disposed using a semiconductor device and a Switch of energy SW2. The inverter using a semiconductor device inverts the DC power source into the AC power source, and drives a high-voltage transformer 10. A first primary coil 11 and a second primary coil 14 are wound on an input portion of the I high-voltage transformer 10. The first primary coil 11 receives the AC power source, and the second primary coil 14 receives the inverted AC power source inverted by the inverter . In addition, a first secondary coil 12 and a second secondary coil 13 are wound on an output part of the high voltage transformer 10 together with a capacitor high-voltage HVC, one HDV high-voltage diode and one | Magnetron MGT. As shown in Figure 3, the inverter 20 using the semiconductor device comprises an activator circuit 1, a plurality of thyristors thl and th2 and a condenser Cl. The plurality of thyristors thl and th2 is connected or disconnected by a switching operation of the activating circuit 1, and in turn a current in the second "Primary coil 14 of the high voltage transformer 10 is thus produced, thus generating the AC power source which has a desired voltage in the high voltage transformer 10. However, in this type of microwave oven CA / CD provided with the inverter that uses the semiconductor device, there is a problem. That is, since it is necessary to provide a plurality of devices expensive semiconductors for the inverter to produce a desired high voltage for the magnetron, the manufacturing cost increases. In the above conventional AC / DC microwave oven, there is also the problem that the useful life of the battery supplying the DC power source is short, since the friction velocity of the current through the semiconductor device is very high. high. In the above conventional AC / DC microwave oven, there is another problem that, since the semiconductor device generates excessive heat, the energy loss due to heat is increased. In the above conventional AC / DC microwave oven, there is also the additional problem that, since the size of the cooling fins is increased to cool the semiconductor device, the size of the microwave oven also has to be increased.

BRIEF DESCRIPTION OF THE INVENTION The present invention has been designed to overcome the above problems and, accordingly, an object of the present invention is to provide a microwave oven of the CA / CD type whose manufacturing cost is reduced. Another object of the present invention is to provide a microwave oven of the AC / DC type, in which the friction velocity of the current through the semiconductor device is eased, and the battery life is much longer.

Another objective of the present invention is to provide a microwave oven of the CA / CD type, in which the energy loss by heat is reduced. A further object of the present invention is to provide a microwave oven of the CA / CD type whose size is small, thus facilitating the management of it. Still another objective of the present invention is to provide a microwave oven of the CA / CD type that is capable of stably producing the microwaves. The above objective is achieved by the microwave oven of the AC / DC type according to the present invention, comprising a rotatable inverter which inverts a DC power source into an AC power source by means of a rotating force, a transformer High voltage that receives a common power source or an AC power inverted by the inverter rotatable and produces a higher voltage, and a magnetron that is powered by the high voltage produced from the high voltage transformer and radiates a microwave. The rotatable inverter comprises a motor that generates the rotating force, a commutator driven by the motor and a plurality of brushes that, respectively, come into contact with the outer surface of the commutator. The commutator comprises a cylindrical body made of an insulating material, and conductive parts which are divided into equal numbers by non-conductive parts, respectively, having a desired width, whereby two brushes which are adjacent to one another come into contact simultaneously with a side of the conductive parts. Each of the non-conductive parts has a width that is greater than one end of the brush, or that is equal to the end thereof. The rotatable inverter further comprises an energy switch that connects or disconnects the DC power source with the motor and the brushes. A pair of the brushes that are opposite each other are connected through the power switch to the DC power source, and the other pair of the brushes that are opposite each other are connected to the side of the high voltage transformer. The motor is connected in parallel with a pair of brushes that are connected through the power switch to the CD power source. The power switch is connected in parallel with a capacitor. Between the respective brushes, which are adjacent to each other, respectively, diodes are connected to avoid a backward voltage. The high voltage transformer comprises a first primary coil to which the common power source is fed, and a second primary coil to which the AC power source inverted by the rotatable inverter is fed. The second primary coil is made of a plate-type coil having a cross-sectional area greater than that of the first primary coil. Another object of the present invention is achieved by the AC / DC microwave oven according to the present invention, comprising a rotatable inverter which inverts a DC power source into an AC power source by means of a rotating force , a high-voltage transformer that receives a common power source or an inverted AC power by the rotating inverter and produces a higher voltage, a magnetron that is powered by the high voltage produced from the high-voltage transformer and radiates a microwave , an AC load driven by the common power source, and a DC load driven by the DC power source that is supplied to the rotatable inverter. This microwave oven also comprises a first power switch that connects or disconnects the AC power source with the high voltage transformer, a first main switch that is connected together with the drive of the transformer and drives the AC load, a second power switch that connects or disconnects the DC power source with the rotatable inverter, and a second main switch that is connected together with the rotatable inverter drive and drives the DC load. Another object of the present invention is achieved by the AC / DC microwave oven according to the present invention, comprising a rotatable inverter which inverts a DC power source into an AC power source by means of a rotating force, a high-voltage transformer that receives a common power source or an inverted AC power by the rotating inverter and produces a higher voltage, a magnetron that is powered by the high voltage produced from the high-voltage transformer and radiates a microwave , and an AC / DC load powered by the common power source or CD power source that is > supplied to the rotating inverter. This microwave oven 5 further comprises a first power switch that connects or disconnects the AC power source with the high voltage transformer, a second power switch that connects or disconnects the DC power source with the rotatable inverter, and a main switch that is connected together with the transformer drive or rotary inverter drive and drives the AC / DC load. Yet another object of the present invention is achieved by the AC / DC microwave oven according to the present invention, comprising a rotatable inverter which invests a DC power source in an AC power source by means of a rotating force, a high-voltage transformer that receives a common power source or a ^ AC power inverted by the inverter rotatable and produces a higher voltage, a magnetron that is powered by high voltage produced from the high-voltage transformer and radiates a microwave, and a control unit that controls the operation of the rotatable inverter to produce a stable frequency. The control unit comprises rotary speed detecting means which detect the rotational speed of the switch, a microcomputer that compares the rotary speed of the switch detected by the rotary means of speed detection with a rotary speed of reference and produces the corresponding signal to control the rotating speed, rotating means of speed adjustment > which adjust the rotating speed of the motor according to the signal of the microcomputer. The rotary speed sensing means has at least one switching transistor of which a terminal base is connected to one of the brushes, the switching transistor being turned on / off by the rotation of the switch 130, thus generating a pulse. The rotary means of adjustment? They have at least one switching transistor which is connected / disconnected by the signal to control the rotating speed of the microcomputer, thus adjusting the rotational speed of the motor. Another further objective of the present invention is achieved by the AC / DC microwave oven according to the present invention, comprising a rotatable inverter that > inverts a DC power source into an AC power source by means of a rotating force, a transformer high voltage that receives a common power source or an inverted AC power by the inverter rotatable and produces a higher voltage, a magnetron that is powered by the high voltage produced from the high voltage transformer and radiates a microwave, a load of CA powered by the source of common power, a DC load driven by the DC power source that is supplied to the rotatable inverter, and a control unit that controls the operation of the rotatable inverter to produce a stable frequency. Yet another object of the present invention is achieved by the AC / DC microwave oven in accordance with present invention, comprising a rotatable inverter which inverts a DC power source into an AC power source by means of a rotating force, a high-voltage transformer that receives a common power source or an inverted AC power by the inverter rotatable and produces a higher voltage and one magnetron that is powered by the high I voltage produced from the high-voltage transformer and radiates a microwave, an AC / DC load powered by the common power source or the CD power source that is supplied to the rotary inverter, and a control unit that controls the operation of the rotating inverter to produce a stable frequency. Therefore, in accordance with the present invention, the manufacturing cost is reduced, the friction velocity of the current is reduced, the energy loss by heat is also reduced, the size of the microwave oven may be smaller, the output frequency of the rotatable inverter may be controlled to remain constant, and the microwaves are also radiated more stably. BRIEF DESCRIPTION OF THE DRAWINGS The above objects and advantages will be more evident by describing the present invention in relation to the drawings accompanied by references, in which: >; Figure 1 is a circuit diagram of a microwave oven of the conventional CA type; Figure 2 is a circuit diagram of another microwave oven of the conventional CA / CD type; Figure 3 is a circuit diagram of the inverter used in the microwave oven of the CA / CD type of Figure 10 2; Figure 4 is a block diagram of the microwave oven of the CA / CD type according to the first preferred embodiment of the present invention; Figure 5 is a circuit diagram of the microwave oven of the CA / CD type of Figure 4; Figures 6 and 1 are views showing the operations of how the DC current is inverted in a > AC current according to the present invention; Figure 8 is a schematic view showing the connected state of the component elements of the present invention; Figure 9 is a perspective view of the high voltage transformer according to the present invention; Figure 10 is a circuit diagram in accordance with the second preferred embodiment of the present invention; Figure 11 is a circuit diagram in accordance with the third preferred embodiment of the present invention; Figure 12 is a block diagram in accordance with the fourth preferred embodiment of the present invention; Figure 13 is a circuit diagram of the figure 12; Figure 14 is a circuit diagram in accordance with the fifth preferred embodiment of the present invention; and Figure 15 is a circuit diagram in accordance with the sixth preferred embodiment of the present invention.

DETAILED DESCRIPTION OF THE PREFERRED MODALITY Figure 4 shows a circuit diagram of the microwave oven of the CA / CD type according to the first preferred embodiment of the present invention. Figure 5 is a circuit diagram of the figure. In Figure 4, a reference number 100 denotes a rotatable inverter, 110 is a motor, 121 to 124 are brushes, 130 is a switch, 200 is a high-voltage transformer, and MGT is a magnetron. The rotatable inverter 100 comprises the switch 130, the brushes 121, 122, 123, 124, and the motor 110. Each of the brushes 121, 122, 123, 124 is in contact with the outer surface of the switch 200. The switch 200 is rotated by the motor 110. The rotatable inverter 100 inverts a DC power source into a source 5 of AC power by rotating the switch 130. The high voltage transformer 200 receives the inverted AC power source by the rotary inverter 100 and produces a desired high voltage. The magnetron MGT is driven by the high voltage produced from the high voltage transformer 200, and radiates a microwave. ? In Figure 5, the high-voltage transformer 200 comprises a first primary coil 201, a second primary coil 202, a first secondary coil 211 and a second secondary coil 212. Here, the first and second coils primaries 201 and 202 are wound on an inlet part, and the first and second secondary windings 211 and 212 are wound on an outlet part. The common AC power source is fed to the first primary coil 201, and the AC power inverted by the rotatable inverter 100 is is fed to the second primary coil 202. The common AC power source is fed through a power switch SW1 to the first primary coil 201 of the high voltage transformer 200. The power switch SW1 connects or disconnects the first coil primary 201 transformer high voltage 200 with AC power source. A DC power source is supplied via an energy switch SW2 to the rotatable inverter 100. The power switch SW2 connects or disconnects the rotatable inverter 100 with the CD power source. The rotatable inverter 100 comprises the switch 130, the brushes 121, 122, 123, 124, and the motor 110. Each of the brushes 121, 122, 123, 124 is in contact with the outer surface of the switch 130. The switch 130 is rotated by the motor 110. Here, a pair of brushes 121 and 123 which are opposite each other are connected to the DC power source, and the other pair of brushes 122 and 124 which are opposite each other are connected to the second primary coil 202 of the high-voltage transformer 200. Each of the diodes DI, D2, D3, D4 which prevent a backward voltage, is respectively connected between the respective brushes 121, 122, 123, 124, which are adjacent to each other. yes. The motor 110 is connected to the DC power source in parallel with the pair of brushes 121 and 123. Therefore, the DC power source is supplied to the brushes 121 and 123, and the motor 110 through the power switch SW2. A capacitor C2 is connected to the power switch SW1 in parallel. The switch 130 comprises a cylindrical body 131 and conductive portions 132 that are formed on the outer surface of the cylindrical body 131. The conductive portions 133 are respectively divided into equal numbers by non-conductive portions 133 having a predetermined width, and connected respectively with the two brushes that are adjacent to each other. A high voltage capacitor HVC, a high voltage diode HVD and the magnetron MGT, are connected to the first secondary coil 211 and the second secondary coil 212 of the high voltage transformer 200. The construction and operation thereof are equal to those of the prior art, so that a detailed explanation thereof is omitted. Figures 6 and 7 are views showing the operations of how the DC current is inverted in an AC current in accordance with the present invention. As shown in Figure 6, a current is fed from a positive terminal of the CD power source to the upper brush 121, and flows through the conductive part 132 of the switch 132 and the left brush 122 from a lower portion of the second primary coil 202 towards an upper portion of the second primary coil 202. In addition, the current is fed to the right brush 124 and is circulated through the conductive part 132 and the lower brush 123 towards a negative terminal of the CD power source. In Figure 7, the positive terminal current of the CD power source is fed to the upper brush 121, and flows through the conductive portion 132 of the switch 130 and the right brush 124 of the upper portion of the second primary coil 202 towards the lower portion of the second primary coil 202, while switch 130 is rotated to a desired angle, eg, at 90 degrees. In addition, the current is fed to the left brush 122 and is circulated through the conductive part 132 and the lower brush 123 towards a negative terminal of the DC power source. Figure 8 is a schematic view showing the connected state of the component elements of the present invention. In Figure 8, a reference number 110 is a motor, 111 is a rotary arrow of the motor 110, and 121 to 124 are brushes, 130 is a switch, 200 is a high voltage transformer, SW2 is an energy switch, C2 is a capacitor, and BATT is a battery. The switch 130 is coupled to the rotating shaft of the motor 110 to be rotated by the rotating effect of the rotating shaft 111. The switch 130 comprises a cylindrical body 131 and conductive portions 132 that are formed on the outer surface of the cylindrical body 131. Each of the conductive parts 132 is divided into an equal number by non-conductive parts 133 having a predetermined width. Here, it is preferable that the non-conductive part 132 has a width that is greater than that of each brush 121, 122, 123, 124, or that it is the same as that of the same. A 12V or 24V battery is used as a means to supply a DC power source. Figure 9 is a perspective view of the high voltage transformer according to the present invention. In Figure 9, a reference number 220 in a core, 201 is a first primary coil, 202 is a second primary coil, 211 is a first secondary coil, and 212 is a second secondary coil. A common AC power source is fed to the first primary coil 201, and inverted by a rotatable inverter. The inverted AC source is fed to the second primary coil 202. And it is preferred that the second primary coil 202 be made of a coil of the plate type having a larger cross-sectional area than the first primary coil 201 for it to be operated on the scale of approximately 50 to 1, 000Hz. The operation of the microwave oven of the type CA / CD previously constructed, in accordance with the first embodiment of the present invention, will be explained in detail by accompanying figures 4 to 9. In the operation by the DC power source, when the power switch SW2 is connected by a user, the DC power source of 12V or 24V of the battery BATT is supplied through the power switch SW2 to the motor 11- 0 and the upper brush 121. The capacitor C2, which is connected in parallel with the switch SW2, charges or discharges a voltage, so that the motor 110 can be rotated uniformly in an initial operation. As shown in Figure 8, the switch 130 is rotated by the rotary arrow 111 of the motor 110. Therefore, the conductive parts 132 are in turn in contact with the respective brushes 121, 122, 123, 124, with which the DC power source is inverted in an AC power source. That is, the DC power source current supplied from the positive terminal of the BATT battery is fed through the upper brush 121 in FIG. 6 to the switch 130. The current thus flows through the conductive part 132 to the left brush 122, and is fed from the lower portion of the second primary coil 202 of the high voltage transformer 200 to the upper part thereof. And then, the current is circulated through the right brush 124, the conductive part 132 and the lower brush 123 towards the negative terminal of the BATT battery. The DC power source supplied from the positive terminal of the BATT battery is fed through the upper brush 121, the conductive part 132 and the right brush 124 from the upper portion of the second primary coil 202 towards the lower portion of the same, while the switch 130 is rotated at a desired angle, for example, at 90 degrees, as shown in figure 7. After that, the current is circulated through the left brush 122, the conductive part 132 and the lower brush 123 to a negative terminal of the battery. Therefore, in any rotation (360 degrees) of the motor 110, the direction of the current in the second primary coil 202 of the high voltage transformer 200 is thus modified twice up and down, thus generating the AC power of a desired frequency. The transformer 200 induces the AC power supplied to the second primary coil 202 in the first and second secondary coils 211 and 212. The first secondary coil 211 preheats the magnetron MGT, and the second secondary coil 212 increases the power fed to approximately 2,000V proportional to a turning ratio. The high energy is further increased through the high voltage capacitor HVC and the high voltage diode HVD to about 4.0OOV, and then supplied to the MGT magnetron. Therefore, 2,450MHz microwaves are generated from the magnetron, and the food in the cooking chamber (not shown) is fired by microwaves. In the operation by the common power source of 110V / 220V, when the power switch SW1 is connected by a user, the common power source of an energy code is supplied through the power switch SW1 to the high voltage transformer 200. The transformer 200 induces the common power supplied to the first primary coil 201 in the first and second secondary coils 211 and 212. The first secondary coil 211 preheats the magnetron MGT, and the second secondary coil 212 increases the power fed to approximately 2,000 V proportional to a rotation ratio. The high energy is further increased through the HVC high voltage capacitor and the HVD high voltage diode to about 4,000V, and then supplied to the MGT magnetron. Therefore, 2,450MHz microwaves are generated from the magnetron, and the food in the cooking chamber (not shown) is cooked by microwaves. In accordance with the AC / DC microwave oven of the present invention, since the number of construction parts thereof can be reduced, its manufacturing cost is reduced. And since the semiconductor device is not used in the above microwave oven, the friction velocity of the current and the loss of energy by heat are also reduced. The size of the microwave oven is also reduced by removing the cooling fins. Figure 10 is a circuit diagram in accordance with the second preferred embodiment of the present invention. In Figure 10, the construction and operation of the motor 110, the rotatable inverter 100, the high voltage transformer 200, the magnetron MGT, the high voltage capacitor HVC and the high voltage diode HVD, are the same as in the first embodiment of the present invention, as shown in Figure 5. The rotatable inverter 100 is provided with the brushes 121, 122, 123, 124 and the switch 130. The transformer 200 has the first and second primary coils 201 and 202, and the first and second secondary coils 211 and 212. However, the microwave oven according to the second preferred embodiment of the present invention further comprises an AC load 410 driven by the common power source, and a load of CD 420 driven by the CD power source supplied to the rotary inverter 100. The AC load 410 is provided with an AC lamp LP1 and an FMl fan motor, and the CD load 420 is provided with a CD LP2 lamp and an engine of FM2 fan. In addition, the above microwave comprises a first power switch SW1, a first main switch SW10, a second power switch SW2 and a second main switch SW20. The first power switch SW1 connects or disconnects the common power source with the high voltage transformer 200. The first main switch SW10 is connected together with the drive of the transformer 200 and drives the AC load 410. The second power switch SW2 connects or disconnects the CD power source with the rotary inverter 100. The second main switch SW20 is connected together with the drive of the rotatable inverter 100 and drives the charging of CD 420. Accordingly, when the first power switch is connected, and the microwave oven is powered by the AC power, the first Main switch SW10 is also connected and operates AC load 410, such as AC lamp LP1 and fan motor FMl. When the second power switch is turned on and the microwave oven is powered by the CD power, the second main switch SW20 is also connected and operates the CD load 420, such as the LP LP2 lamp and the FM2 fan motor. . Therefore, the load of CA 410 and the load of CD 420 are selected automatically, corresponding to the power supplied. Here, lamps LP1 and LP2 illuminate the interior portion of the cooking chamber (not shown), and the ^ Fan motor FMl and FM2 cools the electric parts of the microbond oven, so that it improves the efficiency of cooking. Figure 11 is a circuit diagram in accordance with the third preferred embodiment of the present invention. In figure 11, the construction and operation of the motor 110, the rotatable inverter 100, the transformer 200, the magnetron MGT, the high voltage capacitor HVC and the diode P high voltage HVD, are equal to those of the first embodiment of the present invention, as shown in Figure 5. The rotatable inverter 100 is provided with the brushes 121, 122, 123, 124, and the switch 130. The transformer 200 has the first and second primary coils 201 and 202, and the first and second secondary coils 211 and 212. However, the microwave oven according to the third preferred embodiment of the present invention further comprises an AC / DC 430 load, the which can be powered by the common power source or the AC power induced by the high voltage transformer 200 corresponding to the operation of the rotatable inverter 100. The AC / DC load 430 has an AC lamp LP3 and a fan motor FM3. In addition, the above microwave comprises a first energy switch SW1, a second power switch SW2 and one main switch SW30. The first power switch SWl connects or disconnects the common power source with the high-voltage transformer 200. The second power switch SW2 connects or disconnects the DC power source with the rotatable inverter 100. The main switch SW30 is connected together with the drive of the high voltage transformer 200 or the rotatable inverter 100, and drives the AC / DC load 430. Here, the common power source is fed to the first primary coil 201 of the transformer 200, and the inverted AC power by the rotatable inverter 100 is fed to the second primary coil 202. These AC energies are induced to the first and second secondary coils 211 and 212 and also, the first primary coil 201. The AC / DC load 430 is connected to the common power source in the first primary coil 201. Thus, when the first power switch is connected and the microwave oven is powered by the AC power, the power switch Incl. SW30 is also connected and operates the AC / DC load 430, such as the LP3 lamp and the FM3 fan motor. Similarly, when the second power switch is turned on and the microwave oven is powered by the DC power, the main switch SW30 is connected and operates the AC / DC 430 load, such as the LP3 lamp and the FM3 fan, with the AC power induced by the first primary coil 201 of the high voltage transformer 200. Here, the LP3 lamp illuminates an inner portion of the cooking chamber (not shown), and the FM3 fan motor cools the parts in the microwave, so that cooking efficiency is improved. Therefore, since the LP3 lamp and the FM3 fan motor are driven by the common power source, as well as the AC power inverted by the rotatable inverter 100, the number of the construction parts of the microwave oven is reduced, and the manufacturing cost thereof is also reduced. Fig. 12 is a block diagram in accordance with the fourth preferred embodiment of the present invention, and Fig. 13 is a circuit diagram of Fig. 12. In Fig. 12, the construction and operation of the motor 110, the rotatable inverter 100, the transformer 200, the magnetron MGT, the high-voltage capacitor HVC and the high-voltage diode HVD, are the same as those of the first embodiment of the present invention, as shown in FIG. 4. The rotatable inverter 100 is provided with the brushes 121, 122, 123, 124, and the switch 130. However, the microwave oven according to the fourth preferred embodiment of the present invention further comprises a control unit 300 which controls the operation of the rotatable inverter 100. to produce a stable frequency. The control unit 300 comprises speed detecting rotary means 320, a microcomputer 330 and rotary speed adjusting means 310. The speed detecting rotary means 320 detects a rotary speed of the switch 130. The microcomputer 330 compares the rotational speed of the switch 130 detected by the rotary speed sensing means 320 with a rotary reference speed, and ^ produces a signal to control the rotary speed. The rotary speed adjusting means 310 adjusts the rotary speed of the motor 110 according to the signal from the microcomputer 330. In FIG. 13, the first and second primary windings 201 and 202 of the high voltage transformer 200 are wound on the part of it, and the first and10 second secondary coils 211 and 212 are wound on the? outside of it. The common power source is fed to the first primary coil 201, and the AC power inverted by the rotatable inverter 100 is fed to the second primary coil 202. The MGT magnetron, the capacitor high voltage HVC and the high voltage diode HVD, are connected to the first and second secondary coils 211 and 212 of the output part. The rotary means of detection of > speed 320 have a switching transistor Q4 of which a base terminal is connected to one of the brushes 123. The switching transistor Q4 is switched on / off by rotating the switch 130, thereby generating a pulse. The rotary speed adjusting means 310 is provided with one or more switching transistors Ql, Q2, Q3, which are respectively connected / disconnected by the signal to control the rotating speed from the microcomputer 330.

Now, the operation of the main part of the microwave oven according to the fourth embodiment hereof is explained in detail, while the operation of the same part is omitted as in the first embodiment. When the power switch SW2 is connected by a user, the DC power source of 12V or 24V of the BATT battery is supplied through the power switch SW2 to the motor 11D of the rotatable inverter 100 and the upper brush 121. The motor 110 rotates the switch 130 coupled to the rotary arrow 111 thereof. Therefore, the conductive parts 132 on the outer surface of the switch 130 are in turn in contact with the respective brushes 121, 122, 123, 124, whereby the DC power source is inverted in a power source of CA. This inverted AC power is supplied to the second primary coil 202 of the high voltage transformer 200. Here, the frequency of the AC power flowing in the second primary coil 202 of the high voltage transformer 200 is determined by the number of rotations of the motor 110. In this situation, the microcomputer 330 produces a reference pulse towards an output port P02, and the rotary speed adjusting means 310 drives the motor 110 at a rotational speed corresponding to the reference pulse. The motor 110 rotates the switch 130. At this time, the conductive part 132 and the non-conductive part 133 of the switch 130 are alternately contacted with the respective brushes 121, 122, 123, 124, and invert the CD energy in the AC power. And, in accordance with the rotation of the switch 130, the transistor Q4 of the speed detecting rotary means 320 connected to a side 5 of the brush 123 is on / off. That is, the base terminal of the transistor Q4 is connected to the brush 123, so that the base current can be supplied to the transistor Q4. When the conductive part 132 comes into contact with the brush 123, the transistor Q4 is connected. And when the non-conducting part 133 comes into contact with the brush 123, the transistor Q4 is switched off. Therefore, the pulse of a desired frequency that is generated to correspond to the switching of transistor Q4, is fed to an input hole P03 of the microcomputer 330. The microcomputer 330 calculates the value of the rotary speed of the switch 130, using the pulse of the desired frequency that is sent from the means Velocity detecting rotary 320, and then comparing the calculated value with the rotary reference speed, and produces the corresponding signal to control the rotary speed towards the exit hole P01. If it is determined that the rotational speed of the switch 130 is equal to the rotary reference speed, a signal is produced to maintain the common rotational speed of the motor 110. If determines that the rotational speed of the switch 130 is less than the reference rotational speed, a signal is produced to accelerate the rotary speed of the motor 110. If it is determined that the rotational speed of the switch 130 is greater than the rotary reference speed, a signal is produced to slow down the rotating speed. Here, the microcomputer 330 switches the transistors Ql, Q2, Q3 of the rotating speed control part 310, so that the rotary speed of the motor 110 is accelerated or decelerated. Therefore, the microcomputer 330 repeatedly performs the above processes, and the rotational speed of the motor 110 remains constant. The AC power of a constant frequency is thus supplied to the high-voltage transformer 200, whereby the MGT magnetron can radiate the microwaves stably. Figure 14 is a circuit diagram in accordance with the fifth preferred embodiment of the present invention. In Fig. 14, the construction and operation of the motor 110, the rotatable inverter 100, the transformer 200, the magnetron MGT, the high-voltage capacitor HVC, the high-voltage diode HVD and the control unit 300, are equal to of the fourth embodiment of the present invention, as shown in Figure 13. The rotatable inverter 100 is provided on the brushes 121, 122, 123, 124, and the switch 130. The transformer 200 contains the first and second primary coils 201 and 202, and the first and second secondary coils 211 and 212. The control unit 300 comprises the speed detecting rotary means 320, the microcomputer 330 and the rotatable speed adjusting means 310. However, the microwave oven of according to the fifth preferred embodiment of the present invention further comprises an AC load 410 driven by a common power source, and a load of CD 420 driven by the DC power supply supplied to the inverse rotatable 100. The AC load 410 is provided with an AC lamp LP1 and an FM1 fan motor, and the CD load 420 is provided with a LP lamp LP2 and a fan motor FM2. In addition, the above microwave comprises a first power switch SW1, a first main switch SW10, a second power switch SW2 and a second main switch SW20. The first power switch SWl connects or disconnects the common power source with the high voltage transformer 200. The first main switch SW10 is connected together with the drive of the transformer 200 and drives the AC load 410. The second power switch SW2 connects or disconnects the CD power source with the rotatable inverter 100. The second main switch SW20 is connected together with the drive of the rotatable inverter 100 and drives the charging of CD 420. Accordingly, when the first power switch is connected and the microwave oven is powered by the AC power, the first main switch SW10 is also connected and operates the AC load 410, such as the AC lamp LPl and the fan motor FMl. When the second power switch is turned on and the microwave oven is powered by the DC power, the second main switch SW20 is also connected and operates the CD load 420, such as the LP LP2 lamp and the FM2 fan motor. . Therefore, the load of CA 410 and the load of CD 420 are selected automatically, corresponding to the power supplied. Here, the lamps LPl and LP2 illuminate an interior portion of the cooking chamber (not shown), and the fan motor FMl and FM2 cools the electrical parts in the microwave oven, so that the cooking efficiency is improved. Figure 15 is a circuit diagram in accordance with the sixth preferred embodiment of the present invention. In Figure 15, the construction and operation of the motor 110, the rotatable inverter 100, the transformer 200, the MGT magnetron, the HVC high voltage capacitor, the HVD high voltage diode, and the control unit 300, are the same as those of the fourth embodiment of the present invention, as shown in FIG. 13. The inverter is rotatable 100 is provided with the brushes 121, 122, 123, 124, and the switch 130. The transformer 200 has first and second primary coils 201 and 202, and first and second secondary coils 211 and 212. The control unit 300 comprises the means speed detecting rotary 320, microcomputer 330 and rotating speed adjusting means 310. However, the microwave oven according to the sixth preferred embodiment of the present invention further comprises an AC / DC load 430 which can be driven by a common power source or the AC power induced by the high voltage transformer 200, which corresponds to the operation of the rotatable inverter 100. The AC / DC load 430 has an AC lamp LP3 and an FM3 fan motor. In addition, the above microwave comprises a first power switch SW1, a second power switch SW2 and a main switch SW30. The first SW1 power switch connects or disconnects the common power source with the high voltage transformer 200. The second power switch SW2 connects or disconnects the DC power source with the rotatable inverter 100. The main switch SW30 is connected together with the drive of the high voltage transformer 200 or the rotatable inverter 100, and drives the AC / DC load 430. Here, the common power source is fed to the first primary coil 201 of the transformer 200, and the AC power inverted by the rotatable inverter 100 is fed to the second primary coil 202. These AC energies are induced to the first and second secondary coils 211 and 212 and also, the first primary coil 201. The AC / DC load 430 is connected to the common power source in the first primary coil 201. Thus, when the first power switch is connected, and the microwave oven is powered by the AC power, the main switch SW30 is also connected and operates the AC / DC load 430, such as the LP3 lamp and the FM3 fan motor. Similarly, when the second power switch SW2 is turned on and the microwave oven is driven by the DC power, the main switch SW30 is turned on and operates the AC / DC load 430, such as the LP3 lamp and the FM3 fan motor, with the AC power induced by the first primary coil 201 of the high voltage transformer 200. Here, the LP3 lamp illuminates an inner portion of the cooking chamber (not shown), and the FM3 fan motor cools the electric parts in the microwave oven, so that the cooking efficiency is improved. Accordingly, since the lamp LP3 and the fan motor FM3 are driven by the common power source, as well as the inverted AC power by the rotary inverter 100, the number of the construction parts of the microwave oven decreases, and the manufacturing cost is reduced considerably. In accordance with the AC / DC microwave oven of the present invention, since the number of construction parts thereof can be reduced, the manufacturing cost is reduced. And, the service life of the battery supplying the DC power source can be much greater, since the semiconductor device described in the prior art is not used, and the friction velocity of the current is very low.

In addition, the loss of energy by heat is reduced, since the semiconductor device described in the prior art is not used. In addition, since the cooling fins used in the prior art can be removed, the size of the microwave oven can be much smaller. Further, in accordance with the present invention, since the output frequency of the rotatable inverter can be controlled to be kept constant, the microwaves are also radiated stably. Although the present invention has been shown and described particularly in relation to the preferred embodiment thereof, it will be understood by those skilled in the art that various changes in form and details may be made herein without departing from the spirit and scope of the invention. , defined by the appended claims.

Claims (25)

NOVELTY OF THE INVENTION CLAIMS

1. A microwave oven of the type CA / CD, characterized in that it comprises: a rotatable inverter that inverts a DC power source in an AC power source by means of a rotary force; a high-voltage transformer that receives a common power source or a 10 AC power inverted by the inverter rotatable and produces a

»Higher voltage; and a magnetron that is powered by the high voltage produced from the high-voltage transformer and radiates a microwave. 2. - An AC / DC microwave oven in compliance 15 with claim 1, further characterized in that the rotatable inverter comprises a motor that generates the rotating force, a commutator driven by the motor and a > plurality of brushes that are in contact respectively with an outer surface of the commutator. ~~ 20

3. - An AC / DC microwave oven according to claim 2, further characterized in that the switch comprises a cylindrical body made of an insulating material, and conductive parts that are divided into an equal number by non-conducting parts , respectively, having a 25 desired width, whereby two brushes, which are adjacent to each other, are in contact simultaneously with one side of the conductive parts.

4. - An AC / DC microwave oven according to claim 3, further characterized in that each of the non-conductive parts has a width that is greater than one end of the brush, or that is equal to the end thereof .

5. - An AC / DC microwave oven according to claim 4, further characterized in that the rotatable inverter further comprises an energy switch that connects or disconnects the DC power source with the motor and the brushes.

6. - An AC / DC microwave oven according to claim 5, further characterized in that a pair of the brushes that are opposite each other are connected through the power switch to the CD power source, and another pair of the brushes that are opposite each other are connected to the side of the high voltage transformer.

7. - An AC / DC microwave oven according to claim 5, further characterized in that the motor is connected in parallel with the pair of brushes that are connected through the power switch to the DC power source.

8. - An AC / DC microwave oven according to claim 5, further characterized in that the power switch is connected in parallel with a capacitor.

9. - An AC / DC microwave oven according to claim 2, further characterized in that between the respective brushes, which are adjacent to each other, are - ^ respectively connected diodes to avoid a backward voltage. 10. An AC / DC microwave oven according to claim 1, further characterized in that the high voltage transformer comprises a first primary coil to which the common power source is fed, and a second primary coil to the what the AC power

10 inverted by the rotary inverter is fed.

11. An AC / DC microwave oven according to claim 10, further characterized in that the second primary coil is made of a coil of the plate type having a greater cross-sectional area than 15 that of the first primary coil.

12. An AC / DC microwave oven, further characterized in that it comprises: a rotatable inverter that inverts a DC power source into an AC power source by means of a rotating force; a high voltage transformer 20 which receives a common power source or AC power inverted by the rotating inverter and produces a higher voltage; a magnetron that is powered by the high voltage produced from the high-voltage transformer and radiates a microwave; an AC load triggered by the source of 25 common energy; and a CD charge driven by the CD power source that is supplied to the rotatable inverter.

13. - An AC / DC microwave oven according to claim 12, further characterized in that the rotatable inverter k comprises a motor that generates the rotating force, a commutator driven by the motor and a plurality of brushes that are in contact respectively with an outer surface of the commutator.

14. - An AC / DC microwave oven according to claim 13, further characterized in that the commutator comprises a cylindrical body made of a material 10 insulator, and conductive parts that are divided into equal numbers by non-conductive parts, respectively, having a desired width, whereby two brushes, which are adjacent to each other, are in contact simultaneously with one side of the conductive parts.

15. An AC / DC microwave oven according to claim 14, further characterized in that each of the non-conductive parts has a width that is greater than a > end of the brush, or that is equal to the end of it.

16. - An AC / DC microwave oven in compliance 20 with claim 12, further characterized in that it comprises: a first power switch that connects or disconnects the AC power source with the high voltage transformer; a first main switch that is connected together with the drive of the transformer and drives the load 25 of CA; a second power switch that connects or disconnects the DC power source with the rotating inverter; and a second main switch that is connected together with the rotary inverter drive and drives the CD load.

17. An AC / DC microwave oven, further characterized in that it comprises: a rotatable inverter that inverts a DC power source in an AC power source by means of a rotating force; a high-voltage transformer that receives a common power source or an inverted AC power by the rotating inverter and produces a higher voltage; a magnetron that is powered by high voltage 10 produced from the high voltage and radiator transformer " a microwave; and an AC / DC load driven by the common power source or CD power source, which is supplied to the rotatable inverter.

18. - An AC / DC microwave oven in compliance 15 with claim 17, further characterized in that the rotatable inverter comprises a motor that generates the force Rotary, a switch driven by the motor and a plurality of brushes that are respectively in contact with an outer surface of the commutator.

19. An AC / DC microwave oven according to claim 18, further characterized in that the switch comprises a cylindrical body made of an insulating material, and conductive parts that are divided into an equal number by non-conductive parts, respectively , having a 25 desired width, whereby two brushes, which are adjacent to each other, are in contact simultaneously with one side of the conductive parts.

20. An AC / DC microwave oven according to claim 19, further characterized in that each of the non-conductive parts has a width that is greater than a 5 end of the brush, or that is equal to the end of it.

21. An AC / DC microwave oven according to claim 17, further characterized in that it comprises: a first power switch that connects or disconnects the AC power source with the power transformer. 10 high voltage; a second power switch that connects or W disconnects the DC power source with the rotary inverter, and • a main switch that is connected together with the transformer drive or the rotatable inverter drive and drives the AC / DC load.

22. An AC / DC microwave oven, further characterized in that it comprises: a rotatable inverter that reverses a ^ CD power source in an AC power source by means of a rotating force; a high-voltage transformer that receives a common power source or AC power 20 inverted by the rotating inverter and produces a higher voltage; a magnetron that is powered by the high voltage produced from the high-voltage transformer and radiates a microwave; and a control unit that controls the operation of the rotatable inverter to produce a frequency 25 stable.

23. - An AC / DC microwave oven according to claim 22, further characterized in that the control unit comprises rotary speed detecting means that detect a rotational speed of the switch; > a microcomputer that compares the rotary speed of the switch detected by the rotary speed sensing means with a rotary reference speed, and produces the corresponding signal for controlling the rotary speed; rotating speed adjustment means that adjust the rotating speed of the motor in accordance with the signal of the 10 microcomputer. t

24. - An AC / DC microwave oven according to claim 23, further characterized in that the speed detecting rotary means has at least one switching transistor of which a base terminal is 15 connected to one of the brushes, the switching transistor being turned on / off by the rotation of the switch 130, thus generating a pulse.

25. - An AC / DC microwave oven according to claim 23, further characterized in that the 20 speed adjusting rotating means have at least one switching tansistor which is switched on / off by the signal to control the rotary speed from the microcomputer, thus adjusting the rotary speed of the motor. 25 26.- An AC / DC microwave oven, further characterized in that it comprises: a rotatable inverter that inverts a DC power source in an AC power source by means of a rotating force; a high-voltage transformer that receives a common power source or an inverted AC power by the rotating inverter and produces a higher voltage; a magnetron that is powered by the high voltage produced from the high-voltage transformer and radiates a microwave; an AC / DC load driven by the common power source or the CD power source, which is supplied to the rotatable inverter; and a control unit that controls the operation of the rotatable inverter to produce a stable frequency.