Abstract: A washing machine, provided with a twistable washing tub inside a perforated spin-drying tub for improving its cleaning effect, is disclosed. The twistable washing tub is repeatedly twisted and untwisted at its sidewall during a washing process, thus repeatedly compressing and releasing the laundry and improving the laundry cleaning effect. The washing machine includes an outer tub containing water therein, and a drive unit installed at a position outside the outer tub and generating rotating force. A washing tub is rotatably set within the outer tub, and is connected to the drive unit at its lower portion. This washing tub is twistable and deformable at its sidewall to compress the laundry contained therein during a rotating action of the washing tub.

Abstract: A non-directional frequency generator inputs direct current power and outputs alternating current power. A high voltage transformer inputs the alternating current power, and either induces a higher voltage for driving the magnetron, or induces and outputs a commonly used alternating current power. A button inputting section includes a microwave oven operating button for driving the magnetron, and a voltage supplying button for supplying the commonly used alternating current power. A microcomputer applies the higher voltage of the high voltage transformer to the magnetron when there is a button input through the microwave oven operating button, while outputting the commonly used alternating current power when there is a button input through the voltage supplying button. Further, a socket outlet is formed on the body of the microwave oven, through which the commonly used alternating power generated at the microwave oven is supplied.

Abstract: A non-directional frequency generator spark prevention apparatus including a plurality of electric connections connected with a direct current power source, i.e., brushes, and a commutator for converting direct current waveform inputted through the brushes into alternating current waveform by rotational movement thereof, and for outputting the alternating current waveform. A voltage pulse controlling part is connected between the brushes of the non-directional frequency generator, while having a resistor and a transistor which are connected in series with each other, and the transistor is operated synchronously with the rotation of the commutator of the non-directional frequency generator. By controlling the electric current to flow through the transistor during the brush-off period, a spark production during the brush-off period can be prevented.

Abstract: Disclosed is a microwave oven having a tray which is arranged in a cooking chamber and on which a food to be cooked or a vessel having accommodated therein a food to be cooked is placed and a tray driving section which is disposed in a driving chamber for transferring rotating force to the tray. The microwave oven comprises tray supporting means for preventing the tray from being released from an original installation position. The tray supporting means includes a first coupling portion which is formed on a driving shaft of the tray driving section, a second coupling portion which is press-fitted around the first coupling portion, and supporting arm portions which extend from the second coupling portion in a radial direction so as to be respectively engaged with an edge of the tray.

Abstract: A transformer having a coil winding structure for transforming a voltage which is inputted through a primary coil section and for outputting a transformed voltage toward a secondary coil section. In the transformer, the primary coil section includes a plurality of sub-coil sections which are connected in parallel, and a plurality of terminals are connected to the plurality of sub-coil sections, respectively, in a manner such that corresponding portions of the sub-coil sections have the same current direction.

Abstract: Disclosed is a power connector for a DC microwave oven, suitable for connecting power cords which are led from a DC power source and have positive and negative polarities, respectively, to a component arranged in a device chamber which is defined in a body of the DC microwave oven. The power connector comprises a connector body fixedly secured to a rear plate of the body of the DC microwave oven; power terminals for positive and negative polarities, the power terminals projecting into the device chamber from a rear surface of the connector body; and power cord connecting means projecting from a front surface of the connector body, for enabling the power cords which are led from the DC power source and have positive and negative polarities, to be connected thereto, respectively.

Abstract: Disclosed is a parts arrangement structure for a DC microwave oven which is formed by a combination of an upper panel, a lower panel and a rear panel, a space inside the DC microwave oven being divided into a device chamber in which a magnetron and an air guide are placed and a cooking chamber in which a rotating motor for rotating rollers and a turntable is placed, the DC microwave oven having a control panel which closes a front end of the device chamber. The parts arrangement structure comprises a high voltage transformer and an inverter circuit board mounted to the lower panel inside the device chamber; and at least one high voltage capacitor mounted to the lower panel below the cooking chamber.

Abstract: A microwave oven comprises a magnetron; a body casing having a cooking compartment receiving microwaves from the magnetron and a cooling compartment formed adjacent to the cooking compartment; a thermoelement installed between the cooking compartment and the cooling compartment, and having a radiator and a heat absorber; a hot air transmitting unit transmitting hot air generated from the radiator of the thermoelement to the cooking compartment; and a cool air transmitting unit transmitting cool air generated from the heat absorber of the thermoelement to the cooling compartment. With this configuration, the cooking compartment can be used as a warmer. Also, the cooling compartment can be used as a cooler.

Abstract: A microwave oven to prevent a tray from deviation from its initial installed position due to vibration and/or shock, so that it can be conveniently used in a vehicle even when the vehicle is in motion. The microwave oven includes a cabinet having a cooking chamber and a driving chamber, high frequency generating section for generating high frequency waves and supplying the high frequency waves to the cooking chamber, a tray rotatably installed on the bottom of the cooking chamber, a food and/or a vessel containing food and being placed on a tray, a tray driving section provided in the driving chamber for rotatably driving the tray, and tray supporting section for rotatably supporting the tray and preventing the deviation of the tray from an initial installed position of the tray.

Abstract: A magnetron driving circuit has a DC/AC conversion section, a transformer, and a capacitor. The DC/AC conversion section converts a direct current inputted from a direct current power source into an alternating current, and outputs the alternating current. The transformer has a primary coil and a secondary coil. The transformer raises a voltage of the alternating current outputted from the DC/AC conversion section and then induces the raised voltage from the primary coil to the secondary coil. The capacitor forms an inductance/capacitance resonance circuit by being connected in parallel with the secondary coil. Thus, in the magnetron driving circuit driven by the direct current power source, since the capacitor with a small capacitance is connected in parallel with the secondary coil of the transformer, the reverse surge voltage induced at the primary coil of the transformer is decreased sharply.

Abstract: A non-directional frequency generator for converting direct current into alternating current includes a direct current input end connected with a direct current power source and an alternating current output end connected with an alternating current output section to prevent a spark of the non-directional frequency generator. The non-directional frequency generator converts direct current inputted from the direct current power source into alternating current, and outputs the alternating current to the alternating current output section. First and second switching sections are connected with the direct current input end and the alternating current output end in order to control the conducting status of the direct current input end and the alternating current output end of the non-directional frequency generator, respectively.

Abstract: A non-directional frequency generator capable of minimizing frictional noise generated due to a mechanical rotation mechanism, including: a plurality of brushes connected with a direct current power source; and a commutator which converts a direct current waveform inputted from one of the brushes into an alternating current waveform by a rotational movement thereof, having a groove formed on an outer circumference thereof slanted inward to the commutator so as to reduce friction with the brushes during the rotation thereof.

Abstract: An AC/DC type microwave oven has a function of managing an input power source. The AC/DC type microwave oven comprises a rotatable inverter which inverts a DC power source to an AC power source by a rotational force, a high voltage transformer which receives a common power source or an AC power inverted by the rotatable inverter and outputs a higher voltage, a magnetron which is driven by the high voltage outputted from the high voltage transformer and radiates a microwave and a power control unit for sensing a signal from a power selecting key and preventing the AC and DC power sources from being simultaneously inputted. Therefore, both of AC power and DC power are prevented from being simultaneously supplied to the microwave oven which could result in a malfunction, or an overload occurs in the electric components of the microwave oven. Therefore, only one input power of the common and DC power sources is selected and, the microwave oven is operated properly.

Abstract: Disclosed is an AC/DC type microwave oven. The AC/DC type microwave oven comprises a rotatable inverter which inverts a DC power source to an AC power source by means of a rotational force, a high voltage transformer which receives a common power source or an AC power inverted by the rotatable inverter and outputs a higher voltage and a magnetron which is driven by the high voltage outputted from the high voltage transformer and radiates a microwave, and further comprises a control unit which controls the operation of the rotatable inverter so as to output a stable frequency. The rotatable inverter comprises a motor, a commutator driven by the motor and a plurality of brushes, which are respectively contacted with an outer surface of the commutator.

Abstract: Disclosed is a rotatable inverter. The rotatable inverter comprises a rotatable inverting means for inverting a DC power source to an AC power source by means of a rotational force, and a transformer which receives the AC power source inverted by the rotatable inverting means and outputs a predetermined higher voltage. The rotatable inverting means comprises a motor generating the rotational force, a commutator driven by the motor and a plurality of brushes which are respectively contacted 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 an even-number by non-conductive parts, respectively, having a desired width. Further, it is preferable that the cooling fan is coupled to the motor along with the commutator.

Abstract: Disclosed is a microwave oven having a wrap film hanger. The microwave oven has a wrap film hanger for receiving a wrap film which is used for sealing an opened side of a vessel. The wrap hanger comprises a cover which is pivotably installed about a rear end thereof so that an opening formed at the upper surface of the outer panel is covered by the first cover, a support for rotatably supporting the roll of wrap film in a space formed between the first cover and an upper surface of the cabinet assembly, a first roller installed at a front inner side of the first cover, a second roller disposed below the first roller in such a manner that a nip is formed between the first and second rollers so that the wrap film is passed out through the nip, and a cutting means for cutting the wrap film when the wrap film passing through the nip is ejected from a gap formed between the first cover and the outer panel.

Abstract: A microwave oven door includes a shielding panel, which is made of a material through which microwaves cannot pass, having a contact section that opposes a front panel of the oven when the door is closed. A plurality of slits arranged in the contact section and/or the front panel, or both, prevent microwaves from leaking out through a gap formed between the front panel and the contact section. The slits are arranged in at least one row shaped as a closed loop and are evenly spaced from each other. The length of each slit corresponds to about 1/2 of a wavelength of a microwave, and the width of each slit corresponds to no more than 1/16 of the wavelength of the microwave. The interval between two adjacent slits corresponds to no more than 1/16 of the wavelength of the cooking microwave.

Abstract: A microwave oven includes a cooking chamber and a steam generator for supplying steam thereto for preventing food from drying out during cooking. The steam generator includes a water storage tank and a pair of spaced-apart electrodes mounted in the tank for producing an electrical current across the water in the tank, thereby heating the water to form steam. The water may contain an electrical conducting substance such as sodium chloride to facilitate generation of the electrical current.