Abstract: An axial extractor to efficiently extract microwave power from any magnetron. The axial extractor is both more compact and offers improved overall performance compared to the prior art. The axial extractor allows for suppression of the parasitic magnetron 0 mode, lowers field stress inside the device, and lowers the frequency of operation. These improvements also make it possible for the magnetron itself to be made smaller without a loss of power output.

Abstract: A magnetron that includes a choke coil which is connected at one end to a cathode terminal and at the other end to a capacitor to form an LC circuit. The choke coil is made up of a first core type inductor, a second core type inductor and an air-core inductor, connected to the cathode terminal, all of which are connected in series and where the first and second core type inductors are separated by a 1 mm to 6 mm gap. The first and second core type inductors have a bar like, high-frequency absorbing member located within their respective windings.

Abstract: A magnetron arrangement has a coaxial output terminating in a probe which launches energy from the magnetron along a rectangular waveguide. The coaxial output is arranged in an endfire configuration with respect to the waveguide, giving a compact arrangement compared to conventional output designs.

Abstract: In a magnetron 41, when a radius of a flat portion 45b of a pole piece 45 is Rp, a radius of the inner circumference of a large-diameter equalizing ring 51 is Rs2, Rp?Rs2, a radius of the outer circumference of a small-diameter equalizing ring is Rs1, a radius of a circle inscribed in a leading edge of an anode vane is Ra, and a minimum length between the pole pieces in the axial direction is Lg, the values of Ra, Rs1, Rs2, and Lg are set such that the following Expressions 1 and 2 are established: 1.85Ra?(Rs1+Rs2)/2?1.96Ra, and[Expression 1] 2.84Ra?Lg?3.0Ra.

Abstract: A pulse magnetron includes a cylindrical shell anode, a cathode provided at the center of the anode having a number of vanes mounted radially on an inner wall of the cylindrical anode shell, and a pair of pole pieces provided for applying a magnetic field to an interaction space where the outer side of the cathode is opposed to inner ends of the vanes. The anode and the cathode are arranged to satisfy at least either (i) increasing the radius of the inscribed circle defined by the inner ends of the vanes or (ii) decreasing the radius of the cathode surface as the magnetic flux density along the axial direction of the cathode at both ends of the inner end of the height of the vanes.

Abstract: A device that converts non-visible electromagnetic energy into light. The device includes a cylindrical electromagnetic resonator with a central through hole, a dielectric (preferably ceramic) material surrounded by symmetrically displaced through holes surrounding the central through hole. The device also includes a base and probes connected to the base. The probes are placed to introduce non-visible electromagnetic energy into the resonator. The device also includes a plasma lamp placed in the central through hole. The plasma lamp is placed to convert the non-visible electromagnetic energy into light. Preferably, the resonator is composed of a ceramic with a metalized surface except for inside the through holes.

Abstract: A low-output microwave lighting system includes: a rectifier for rectifying general AC power inputted through a power source unit and outputting a DC voltage; a power factor compensator for compensating a power factor of the DC voltage inputted through the rectifier; and an inverter circuit unit for receiving the power factor-compensated DC voltage and outputting an AC voltage through frequency varying. 120 Hz of ripple generated at a low output can be reduce, and it is driven at a frequency of 20 KHz or higher, so that a flicker phenomenon does not occur and a volume and weight in facility can be reduced.

Abstract: A magnetron includes a decoupling plate located between the end hat of the magnetron cathode and an output coupling member. The use of the decoupling plate presents a high impedance and gives a resonant circuit which is arranged to be resonant at the operating frequency of the magnetron. This prevents or reduces power loss due to capacitive coupling. In another arrangement, the decoupling plate is mounted to a post on the end hat of the magnetron cathode.

Abstract: A magnetron includes a ring-shaped anode, a cathode, an activating space, at least one permanent magnet and a magnetic flux carrying unit. The ring-shaped anode forms a plurality of resonance circuits. The cathode is disposed at the axial center of the anode to emit thermions. The activating space is formed between the anode and the cathode. The at least one permanent magnet is provided beside the anode. The magnetic flux carrying unit carries magnetic flux generated by the at least one permanent magnet to the activating space. A microwave oven and/or high frequency heating apparatus may utilize the magnetron.

Abstract: A magnetron comprising an anode portion having an anode cylinder and vanes, a cathode portion having a coil-shaped filament, magnetic poles disposed at the upper and lower ends of the filament, ring-shaped permanent magnets made of a Sr ferrite magnet containing La—Co, an input portion and an output portion. The diameter ?a of the inscribed circle at the ends of the vanes constituting the anode portion is in the range of 7.5 to 8.5 mm, and the outside diameter ?c of the coil-shaped filament 1 constituting the cathode portion is in the range of 3.4 to 3.6 mm.

Abstract: Intensive microwave radiation in particular of great band width and energy over a relatively long period of time in the form of long pulse packets with a high pulse repetition frequency and a very high frequency spectrum can be achieved if microwave irradiation is effected during the discharge of a capacitive high-voltage generator (35) by way of the antenna (26) into a series of successive capacitors (13) to be connected in parallel. They are preferably constructed in the form of a concentric stack, connected to the antenna (26), of which the outer electrodes (16) which are at a reference potential are in the form of a continuous tube within which annular electrodes (15) are disposed on a carrier (20) in axially spaced relationship with each other in such a way that at the same time they act as the electrodes of arc switches (39) for successively switching on subsequent capacitors (13).

Abstract: A magnetron cathode assembly which realizes stopping of turn of an external terminal inserted into a stem insulator without increasing a manufacturing cost. A leading end of a base end axial portion of an external terminal has a non-circular section by providing a flat surface in at least one position on its peripheral surface, and a straight stop edge that fits to the flat surface thereby to carry out stopping of turn of the external terminal is provided for a terminal fitting hole of a sealing metal plate into which the leading end of this external terminal is fitted.

Abstract: The object to the present invention is to provide a magnetron which can reduce spurious oscillation such as the ??1 mode which presents a problem particularly in magnetrons and can reduce spurious radiations without placing filters. The magnetron of the present invention includes an anode 1 formed by plural vanes 12 in such a manner that inner ends 12 are radially extended toward the center of the anode shell 11 from the inner wall of a cylindrical anode shell, and a cathode 2 provided at the center of the anode 1. The magnetron of the present invention further includes a pair of pole pieces 4 provided in such a manner that a magnetic field can be applied on the interaction space 2 where the inner ends 12a of the vanes 12 and the cathode 2 face with each other.

Abstract: A magnetron capable of being efficiently assembled is provided. The magnetron includes a filament, a pair of shields, a pair of leads, a pair of connection plates, and a pair of terminal rods. The filament is coil-shaped. The shields are attached to both ends of the filament, respectively. The leads are attached to the shields at first ends of the leads, respectively. The connection plates are attached to second ends of the leads, respectively. The terminal rods are attached to the connection plates, respectively, to supply power to the leads through the connection plates, and have slender protrusions, which have sectional areas smaller than sectional areas of attachment portions of the terminal rods so that the terminal rods are attached to the connection plates with the slender protrusions passing through the connection plates.

Abstract: Anode with a 2450 MHz resonance frequency, and magnetron therewith, the anode including a cylindrical anode body with an inside diameter in a range of 32.5 to 34.0 mm, a total of ten vanes fitted to an inside circumferential surface of the anode body in a radial direction, and an inner strap and an outer strap provided to both of an upper surface and a lower surface of each vane, a distance of the inner strap and the outer strap being in a range of 0.8 to 1.2 mm, and each of the inner strap and outer strap being in contact with every second vanes for electrical connection of the vanes alternately. The anode body and the vanes are formed as one unit for simplification of a fabrication process.

Abstract: A microwave powered lamp head assembly includes a shutter assembly which may be activated to selectively allow transmission of light from the microwave powered lamp bulb. The shutter assembly allows unrestricted airflow when it is in the closed position so that the active lamp bulb may still be cooled, while preventing the transmission of UV radiation through the shutter. The shutter assembly is in close sealing relation with respect to the optical cavity holding the lamp bulb when in the closed position to minimize the escape of UV radiation.

Abstract: A magnetron, and a microwave oven and a high frequency heating apparatus each equipped with the same use, a single permanent magnet disposed above or below an anode, a pole piece near the permanent magnet that has a magnetic flux dispersing structure, and another pole piece opposite to the permanent magnet that has a magnetic flux concentrating structure. In accordance with the present invention, even though a single permanent magnet is provided, magnetic flux density is rendered uniform across an activating space, so that the volume and parts of the magnetron are reduced and the curtailment of manufacturing costs is realized.

Abstract: A portable power converter comprising input means to receive low voltage DC input, voltage converter means for converting the low voltage DC input into high DC voltage output, the voltage converter means in electrical communication with the input means, output means for operably supplying the high DC voltage to an appliance. The output means is in electrical communication with the converter includes a housing adapted to receive at least one of the input means, the voltage converter means and the output means. Preferably, the portable power converter also includes processing means for controlling some of the functions of the device such as shutting it down when power falls below preselected threshold. The device may also include a remote control which may be manually activated or in an alternative embodiment activated by external environment stimuli.

Abstract: A cooling apparatus of a plasma lighting system. The system includes a power supply for supplying a power source; a magnetron for generating electromagnetic wave by the power source from the power supply; a bulb for generating light in accordance with that inert gas is ionized by the electromagnetic wave; and a case unit of a hermetic shape including the magnetron and the power supply therein for cooling heat generated from the magnetron. The plasma lighting system prevents heat of high temperature generated from the magnetron from being transmitted and foreign substance from being introduced.

Abstract: A magnetron includes a positive polar cylinder, a plurality of vanes, a filament, upper and lower shields, and upper and lower pole pieces. The vanes are disposed in the positive polar cylinder to constitute a positive polar section. The filament is disposed on an axis of the positive polar cylinder to define an activating space. The upper and lower shields cover a top and bottom of the filament, respectively. The upper and lower pole pieces are disposed to induce magnetic flux into the activating space. The upper shield preferably has a diameter ranging from 6.95 mm to 7.10 mm. Additionally, the lower shield preferably has a diameter ranging from 6.95 mm to 7.10 mm.

Abstract: It is desirable to be able to provide evenly illuminated, long lasting, relatively high power ultraviolet radiation for manufacturing processes such as sterilization and ink or adhesive curing. A generally rigid waveguide (2) having a slot (8) formed in one of its short sides (4) (or optionally one of its long sides (6)) may have an ultraviolet energizable elongate lamp (10) inserted therein. When the waveguide is coupled to a source of microwave energy, the slot radiates and the radiated energy is coupled almost exclusively into the lamp (10). With suitable choices of slot widths this provides even illumination with minimal microwave leakage.

Abstract: The invention is a microwave powered lamp (10). The lamp includes a light reflective cavity (28); an electrodeless bulb (16) contained in the light reflective cavity (26) from which light is emitted when the electrodeless bulb is excited by microwaves; a magnetron (12) for providing the microwaves for exciting the electrodeless bulb; a waveguide (14) which couples the microwaves emitted by the magnetron to the light reflective cavity for exciting the electrodeless bulb; a housing (22) which contains the lamp; a detector (102, 202) disposed within the housing, which detects the microwaves which are not coupled to the bulb during operation of the magnetron and outputs a signal indicative of a level of received microwaves; and a magnetron control (300), coupled to the detector, which causes the magnetron to be turned off when a level of the signal indicates the level of received microwaves exceeds a threshold.

Abstract: A magnetron for microwave ovens including a second insulator interposed between a connection part and a bottom of a yoke to form a relatively lengthened insulation distance, or a molded insulating plate attached to a bottom of the filter box to reduce a distance between the connection part and a bottom of the filter box. In the magnetron, an entire height of the magnetron is reduced, so that a miniaturization of the magnetron can be implemented and a design of a product including the magnetron, such as a microwave oven, can be freely carried out, thus allowing an appearance of the product to be variously designed.

Abstract: In such a case that a radial dimension of an outer circumference of a small-diameter strap ring of a magnetron is equal to “Rs1”, a radial dimension of an inner circumference of a large-diameter strap ring is equal to “Rs2”, a radius of a circumference which is inscribed to tip portions of anode vanes is equal to “Ra”, and a radius of a central flat portion of a magnetic piece, which is located in the vicinity of each of the anode vanes, is equal to “Rp”, the respective values of Ra, Rs1, Rs2, Rp are set in such a manner that the below-mentioned formulae (1) and (2) can be established: 1.85Ra?(Rs1+Rs2)/2?1.96Ra??(1) Rs1<Rp<Rs2??(2).

Abstract: A multiple beam linear accelerator system and method where two or more accelerator waveguides are driven by a single high power microwave source. A single RF power system is multiplexed to drive the plurality of accelerator waveguides. Each accelerator waveguide is addressed at a different RF frequency, and the microwave source generates pulses at the appropriate RF frequency for each accelerator waveguide on a pulse-by-pulse basis.

Abstract: This invention is directed to crossed-field devices such as magnetrons to an inductive insert for a magnetron that compensates for the natural increase in cavity inductance with temperature which causes the output frequency to decline with increasing temperature.

Abstract: A magnetron includes semi-circularly shaped electric field adjusting grooves provided on surfaces of outer ends of vanes brought into contact with an inner surface of a positive polar body to make distribution of an electric field uniform on the surfaces of the outer ends of the vanes. Accordingly, the electric field becomes uniform by the electric field adjusting grooves provided on the surfaces of the outer ends of the vanes, so that generation of undesirable harmonics is suppressed.

Abstract: A noise filter of a high frequency generator reduces noise of a certain frequency band leaked from the high frequency generator using a structure in which a first core inductor, an air-core inductor and a second core inductor are connected in series to each other. The first and second core inductors have high frequency-energy absorbing members inserted thereinto, and the air-core inductor is not provided with a high frequency-energy absorbing member therein. The high frequency-energy absorbing member is made of one of iron oxide, tin alloy and ferrite. The high frequency-energy absorbing member is also provided with a sectional area in which noise of a frequency band of 400 MHz to 900 MHz is attenuated.

Abstract: A microwave powered lamp head assembly includes a shutter assembly which may be activated to selectively allow transmission of light from the microwave powered lamp bulb. The shutter assembly allows unrestricted airflow when it is in the closed position so that the active lamp bulb may still be cooled, while preventing the transmission of UV radiation through the shutter. The shutter assembly is in close sealing relation with respect to the optical cavity holding the lamp bulb when in the closed position to minimize the escape of UV radiation.

Abstract: A noise filter for a high frequency generator maximizes a frequency band in which noise is attenuated by adjusting a spacing between winding turns of core inductors provided in the noise filter. The noise filter includes a coke coil having a first winding unit having a first spacing between turns thereof, a second winding unit having a second spacing between turns thereof and a third winding unit having a spacing the same as the first spacing between turns thereof. The first, second, and third winding units are connected in series to each other. The noise filter also includes a high-frequency energy absorbing member inserted into the choke coil. The high-frequency energy absorbing member is made of one of iron oxide, tin alloy and ferrite, and includes a sectional area to attenuate noise in a frequency band ranging from 30 MHZ to 1000 MHz.

Abstract: An electrodeless lighting system which is emitting light using microwave generated in a magnetron comprises: a main case including a waveguide through which microwave is transmitted, a resonator coupled to an exit of the waveguide, and a bulb located in the resonator; a subsidiary case including a magnetron generating the microwave, and a high voltage generator for providing the magnetron with high voltage; and a microwave transmission cable connected from the magnetron to the waveguide for transmitting the microwave, whereby the emitting portion can be minimized by separating components which are not really needed for emitting, and lowering of performance and damage of the bulb or the resonator by infiltration of impurities such as dust can be prevented.

Abstract: A magnetron includes a filament to irradiate thermoelectrons, a plurality of anodic vanes arranged around the filament in radial directions, and an antenna connected to at least one of the anodic vanes. The vane connected to the antenna is provided with an antenna holding part. The antenna holding part outwardly extends from an upper edge of the vane by a predetermined length to connect the antenna to the vane.

Abstract: A microwave oven using DC power which can endure strong vibrations and eliminate noise according to noise standards. The microwave oven includes at least one second choke coil which is arranged outside a magnetron filter box and connected in series to at least one first choke coil installed in the magnetron filter box. Each choke coil and a feed-through condenser constitute a low pass filter. The size of each of the first choke coil is reduced and the size of each of the second choke coil is increased, so as to endure the strong vibrations and eliminate the noise generated by a driving of a magnetron.

Abstract: A magnetron for a microwave oven includes a yoke, an anode cylindrical body installed inside the yoke, a plurality of veins mounted inside the anode cylindrical body, a filament installed in a center of the veins, and an upper magnet and a lower magnet respectively mounted on an upper side and a lower side of the anode cylindrical body. The magnetron also includes an upper pole piece and a lower pole piece respectively installed between the anode cylindrical body and the upper and lower magnets. A length (L) from an external tip of a central part of the upper pole piece to an internal tip thereof, on which a hollow part is formed, is adjusted to suppress harmonics in the magnetron. Thus, generation of the harmonics may be effectively attenuated, and an output of a microwave may be enhanced by preventing power consumption of the magnetron which may be large due to interrupting harmonics.

Abstract: A control unit for a magnetron, the circuit being supplied form a source of a.c. voltage and comprising a power switch, a process controller/firing circuit for the power switch and first and second transformers. The first transformer supplies a desired filament voltage to the magnetron and the second transformer controls the current flow in the magnetron and hence the power output. The second transformer is controlled by the operation of the process controller/firing circuit and the power switch to provide an infinitely variable power output setting to the magnetron.

Abstract: An apparatus having a radio frequency resonator, which has a coil, a capacitor means and at least one switch means being associated with another capacitor means, a resistor means and a high voltage supply means, one end of the switch means being connected to a junction of the coil and the capacitor means where a radio frequency voltage is provided, another end of the switch means being connected to ground with said another capacitor means and to the high voltage power supply means with the resistor means.

Abstract: A magnetron for use in, for example, microwave ovens, includes a positive polar cylinder, a plurality of vanes, and large-diameter and small-diameter strip rings. The vanes constitute a positive polar section, along with the positive polar cylinder. The large-diameter and small-diameter strip rings are disposed on an upper portion and a lower portion of the vanes, respectively, to alternatively and electrically connect the vanes to one another. The inside and outside diameters of the large-diameter strip ring are in a range of 17.1 mm to 18.01 mm and 18.6 mm to 19.6 mm, respectively. The inside and outside diameters of the small-diameter strip ring are in a range of 13.4 mm to 14.4 mm and 14.9 mm to 15.9 mm, respectively. The height of the large-diameter and small-diameter strip rings is in a range of 1.50 mm to 1.60 mm. The distance between the large-diameter strip ring and the small-diameter strip ring is maintained in an error range of 2.20 mm.

Abstract: A magnetron includes an anode having an anode cylinder and anode vanes; a cathode having a filament; a condenser, a choke coil, and a plurality of leads for providing power to the filament; a plurality of magnets, pole pieces, and a yoke for forming a magnetic circuit; an antenna feeder and an antenna cap for transmitting a generated microwave outside of the magnetron; and a plurality of joints formed of a joining material between a metal component and a ceramic component of the magnetron. The joining material is diffused between the metal component and the ceramic component, to infiltrate into an inner part of the ceramic component directly, thereby joining the metal and ceramic components, and thereby also improving a reliability of a magnetron, facilitating a simple component assembly process and a simple magnetron fabrication process, permitting simplification of the fabrication process and reduction of a fabrication cost, and saving equipment cost as a high temperature furnace can be dispensed with.

Abstract: Disclosed is a cooling apparatus of a plasma lighting system comprising: a power supply for supplying a power source; a magnetron for generating electromagnetic wave by the power source from the power supply; a bulb for generating light in accordance with that inert gas is ionized by the electromagnetic wave; and a case unit of a hermetic shape including the magnetron and the power supply therein for cooling heat generated from the magnetron. The plasma lighting system prevents heat of high temperature generated from the magnetron from being transmitted and foreign substance from being introduced.

Abstract: A magnetron comprises an anode (2) having vaner (3a, 3b) which define a plurality of cavities. A dielectric resonator (7) is located such that it is in communication with at least one of the vanes (3a, 3b). In use, the dielectric resonator (7) at least partially absorbs spurious radiation generated in a predetermined mode of operation of the magnetron, such as the &pgr;-1 mode. Power generated in the &pgr;-1 mode, if transmitted, may interfere with other electronic devices. The resonator (7) may be of ceramics material, such as alumina.

Abstract: A magnetron includes a ring-shaped anode, a cathode, an activating space, at least one permanent magnet and a magnetic flux carrying unit. The ring-shaped anode forms a plurality of resonance circuits. The cathode is disposed at the axial center of the anode to emit thermions. The activating space is formed between the anode and the cathode. The at least one permanent magnet is provided beside the anode. The magnetic flux carrying unit carries magnetic flux generated by the at least one permanent magnet to the activating space. A microwave oven and/or high frequency heating apparatus may utilize the magnetron.

Abstract: The object of the present invention is to provide a pulse magnetron which can inhibit unwanted oscillation at an operation point lower than the rated level in the rise or decay of a pulse, attenuate spurious radiation at lower frequencies than the fundamental oscillation frequency, and produce an improved symmetrical profile of output spectrum. The pulse magnetron of the present invention includes an anode, a cathode provided at the center of the anode, and a pair of pole pieces provided for applying a magnetic field to an interaction space where the outer side of the cathode is opposed to the inner ends of the vanes. The radius ra of the inscribed circle defined by the inner ends of the vanes and the radius rc of the cathode surface satisfy the operation theory equation for the minimum value of the magnetic flux density along the axial direction of the cathode at both ends of the inner end of the height of the vanes in the interaction space.

Abstract: A microwave oven includes a direct current (DC) power supply unit which supplies DC power to a magnetron so as to suppress noise induced in a high voltage line. The DC power supply unit includes at least one rectifying diode and a choke coil. The rectifying diode rectifies high frequency alternating current (AC) power generated by a heater coil into the DC power to suppress noise induced in the high voltage line of a high voltage transformer. The choke coil forms ripples in the DC power and effectively prevents a moding of the magnetron, which is generated where a constant DC voltage is supplied.

Abstract: A magnetron includes an anode cylinder and anode vanes; a cathode having a filament; a condenser, a choke coil, and a plurality of leads for providing power to the filament; a plurality of magnets, pole pieces, and a yoke for forming a magnetic circuit; an antenna feeder and an antenna cap for transmitting a generated microwave outside of the magnetron; and a plurality of joints formed of a joining material between a metal component and a ceramic component of the magnetron. The joining material is diffused between the metal component and the ceramic component, to infiltrate into an inner part of the ceramic component directly, thereby joining the metal and ceramic components, and thereby also improving a reliability of a magnetron, facilitating a simple component assembly process and a simple magnetron fabrication process, permitting simplification of the fabrication process and reduction of a fabrication cost, and saving equipment cost as a high temperature furnace can be dispensed with.

Abstract: An electrode-less lamp equipment with higher luminance by higher lamp-cooling efficiency wherein the airflow generated by the blower 9 goes through the ventilation hole 12 and spouts out from the open end of the lamp-cooling nozzle 15 and cools the surface of the electrode-less lamp 1 is provided. The velocity of the airflow is accordingly high around the lamp surface enough to efficiently cool the lamp. This makes it possible to raise the input power density to the lamp and to increase luminance.

Abstract: A noise filter of a high frequency generator reduces noise of a certain frequency band leaked from the high frequency generator using a structure in which a first core inductor, an air-core inductor and a second core inductor are connected in series to each other. The first and second core inductors have high frequency-energy absorbing members inserted thereinto, and the air-core inductor is not provided with a high frequency-energy absorbing member therein. The high frequency-energy absorbing member is made of one of iron oxide, tin alloy and ferrite. The high frequency-energy absorbing member is also provided with a sectional area in which noise of a frequency band of 400 MHz to 900 MHz is attenuated.

Abstract: An emission element enclosed inside an electrodeless lamp 5 is excited by an electromagnetic field of a microwave irradiated from a magnetron 2 for emitting light from the electrodeless lamp 5. A soft-starting method is provided such that an electric power enough to drive the magnetron 2 is gradually increased. The soft-starting method is to prevent the magnetron from being destroyed by self-heating due to a reflected wave of the microwave. The soft-staring method is used when a light begins to be emitted from the electrodeless lamp 5. Accordingly, the electrodeless lamp system is provided such that breakage of the magnetron caused by the self-heating due to the reflected wave of the microwave can be prevented.

Abstract: Magnetron including a cylindrical anode having a resonant space formed therein and a cathode fitted therein, magnets fitted to upper and lower sides of the anode, a yoke fitted on outsides of the anode and the magnets to for a closed circuit, and cooling devices including a main cooling device to form a heat discharge path from the anode, and a supplementary cooling device to form a heat discharge path from the magnet direct or indirectly, wherein the main cooling device is an anode heat conductor having one end closely fitted to an outside surface of the anode, and the other end passed to the yoke and exposed to an external air, and the supplementary cooling device includes a magnet heat conductor closely fitted to an outside surface of the magnet, the magnet heat conductor having one side in contact with the outside case of the magnetron, or a yoke heat conductor closely fitted to an outside surface of a yoke plate, the yoke heat conductor having one side in contact with the outside case of the magnetron.

Abstract: A microwave oven includes a filter unit having choke coils disposed on ground lines, to which low and high voltage units are grounded, and on a power line connected to a controller so as to block high frequency noise. Impedances of the ground and power lines are greatly increased by the choke coils. Accordingly, noise is prevented from being radiated to the outside through the ground lines, and from flowing to the controller through the power line, thus allowing the controller to perform a stable operation.

Abstract: A magnetron including a tubular metallic container which is air-tightly connected to an anode, cathode leads for supporting a cathode with filaments being disposed in a central axial portion of the anode, a stem insulator formed with through holes through which the cathode leads pass, and external terminals formed with planar portions which are air-tightly connected to a surface of the stem insulator opposite to a surface facing the tubular metallic container and with connecting portions which are air-tightly connected to the cathode leads. The connecting portions are arranged to be bent in an axial direction of the cathode leads. It is possible to exhibit the effect of preventing vacuum break from occurring by oxidation or the like since the increase in the area of the connecting portions will result in elongation of the distance between the end portions of the connecting portions and the through holes.