With Magnetically Controlled Space Discharge Device (e.g., Magnetron) Patents (Class 331/86)
  • Patent number: 9585202
    Abstract: A system and method for holding and warming food held in pans or trays having a low relative magnetic permeability, such as 300-series stainless steel, using induction heating.
    Type: Grant
    Filed: May 20, 2011
    Date of Patent: February 28, 2017
    Assignee: COOKTEK INDUCTION SYSTEMS, LLC
    Inventors: Warren S Graber, Reinhard Metz, Robert J Visher
  • Patent number: 9105959
    Abstract: An enclosed resonator includes a generally planar plate having a top side and a bottom side wherein a pocket is recessed into the bottom side to produce a bottom surface and a periphery around the rectangular pocket including a first pair of parallel sides and a second pair of parallel sides, a plurality of generally parallel channels formed into the top side each channel extending generally in a direction of the second pair of parallel sides, a first plurality of holes extending along a first side of the first pair of parallel sides each hole extending from the bottom side to one of the plurality of generally parallel channels, a second plurality of holes extending along a second side of the first pair of parallel sides each hole extending from the bottom side to one of the plurality of generally parallel channels.
    Type: Grant
    Filed: September 4, 2012
    Date of Patent: August 11, 2015
    Assignee: WiTricity Corporation
    Inventors: Morris P. Kesler, Konrad Kulikowski, Katherine L. Hall, Andre B. Kurs
  • Patent number: 8441193
    Abstract: A highly-reliable electronic frequency tuning magnetron comprises an anode for forming a resonant cavity which is segmented into a plurality of spaces in an inner periphery side of a cylindrical anode shell, a cathode provided at the center of the anode shell along its cylindrical axial direction and an exhausted structure having a coaxial central conductor which is connected to the inside of the cavity of the anode shell and is coupled thereto in a high-frequency manner, wherein the coaxial central conductor is externally led through a wall of the exhausted structure via a through-hole and the through-hole is covered by a dielectric portion placed between an external conductor for constituting the coaxial central conductor and the central conductor, wherein a portion of the led coaxial central conductor is conductively connected to a switching element.
    Type: Grant
    Filed: October 2, 2009
    Date of Patent: May 14, 2013
    Assignee: New Japan Radio Co., Ltd.
    Inventors: Hideyuki Obata, Kunihiko Takahashi
  • Publication number: 20120062220
    Abstract: A nano-oscillator magnetic wave propagation system has a group of aggregated spin-torque nano-oscillators (ASTNOs), which share a magnetic propagation material. Each of the group of ASTNOs is disposed about an emanating point in the magnetic propagation material. During a non-wave propagation state of the nano-oscillator magnetic wave propagation system, the magnetic propagation material receives a polarizing magnetic field. During a wave propagation state of the nano-oscillator magnetic wave propagation system, each of the group of ASTNOs initiates spin waves through the magnetic propagation material, such that a portion of the spin waves initiated from each of the group of ASTNOs combine to produce an aggregation of spin waves emanating from the emanating point. The aggregation of spin waves may provide a sharper wave front than wave fronts of the individual spin waves initiated from each of the group of ASTNOs.
    Type: Application
    Filed: July 21, 2011
    Publication date: March 15, 2012
    Applicant: NEW YORK UNIVERSITY
    Inventors: Frank C. Hoppensteadt, Andrew D. Kent, Ferran MaciĆ  Bros
  • Patent number: 7724098
    Abstract: The present invention is, in one aspect, a radio frequency source, comprising a gyromagnetic precession oscillator. In a second aspect, the gyromagnetic precession oscillator comprises a closed, non-magnetic, cylindrical outer conductor defining a cavity therein; an axial field solenoid wound about the outer conductor; a non-magnetic, cylindrical inner conductor disposed within the cavity and coaxially aligned with the outer conductor; a plurality of cylindrical ferrite precessors, each defining a respective bore through which the inner conductor runs; a plurality of dividers disposed within and defining a resonant chamber in the cavity; and a dielectric material filling the cavity. In a third aspect, the radio frequency source is actively tunable. In a fourth aspect, the radio frequency source that is tunable pulse-to-pulse.
    Type: Grant
    Filed: August 15, 2008
    Date of Patent: May 25, 2010
    Assignee: Lockheed Martin Corporation
    Inventors: Michael C. Scott, Steve E. Calico, David S. Hidinger, Chris E. Williams
  • Patent number: 7687749
    Abstract: It is an object to provide a magnetron for a small-sized microwave oven which takes safety standards and a noise into consideration, in a magnetron 10 for a microwave oven, a pair of choke coils 16 and 17 are provided in a filter case 11, and a height H1 of the internal surface of the filter case 11 is set to be 35 to 45 mm, an outside diameter d3 of an air-core type inductance 25 is set to be 5.5 to 7.5 mm and a sectional area S of a high frequency absorbing member 27 is set to be 5 to 16 mm2. In the magnetron 10 for a microwave oven, an electrostatic capacity between capacitor terminals 15A and 15B and the filter case 11 is increased to be 500 to 700 pF.
    Type: Grant
    Filed: April 19, 2006
    Date of Patent: March 30, 2010
    Assignee: Panasonic Corporation
    Inventors: Hiroshi Ochiai, Etsuo Saitou, Yoshimasa Suzuki, Nagisa Kuwahara
  • Publication number: 20080238558
    Abstract: A magnetron having a cathode 1 and an anode 2 with vanes 3, has an insulating surface 4 in it which faces the cathode and receives material from it due to sputtering at the cathode. A conductor 7 enables the resistance of the film so deposited to be measured, giving an indication of the thickness of the film and the lifetime of the magnetron.
    Type: Application
    Filed: March 5, 2008
    Publication date: October 2, 2008
    Applicant: E2V Technologies (UK) Limited
    Inventor: Michael Barry Clive Brady
  • Publication number: 20080231380
    Abstract: A magnetron (2), a launcher (4) which extracts the output power of the magnetron (2), an impedance generator (5) having one terminal connected to the output terminal of the launcher (4), and a reference signal supplier (6) connected to the other terminal of the impedance generator (5) are included. The reference signal supplier (6) supplies, to the magnetron (2), a reference signal lower in electric power and stabler in frequency than the output from the magnetron (2). The oscillation frequency of the magnetron (2) is locked to the frequency of the reference signal by injection of the reference signal. The impedance generator (5) can reduce the change width of the oscillation frequency of the magnetron (2) by adjusting the load impedance of the magnetron (2). This implements a magnetron oscillator (1) which has high frequency stability and does not fluctuate the frequency even when the output power is changed.
    Type: Application
    Filed: September 15, 2005
    Publication date: September 25, 2008
    Inventor: Kibatsu Shinohara
  • Patent number: 6985042
    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.
    Type: Grant
    Filed: September 10, 2003
    Date of Patent: January 10, 2006
    Assignee: New Japan Radio Co., Ltd.
    Inventors: Hideyuki Obata, Naoki Tsuji
  • Patent number: 6875970
    Abstract: A safety apparatus for an output level-adjustable microwave oven includes a fuse disposed in a power supply line that connects a high power relay or a low power relay with a primary coil of a high voltage transformer of the microwave oven. Where a wrong operation occurs due to defects in the relays, such as a melting of any one of the relays, the fuse disposed in the power supply line connected to the primary coil of the high voltage transformer is cut off. Accordingly, a potential fire resulting from the wrong operation is prevented.
    Type: Grant
    Filed: March 4, 2003
    Date of Patent: April 5, 2005
    Assignee: Samsung Electronics Co., Ltd.
    Inventor: Sun-Ki Kim
  • Publication number: 20040021522
    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 along with the positive polar cylinder. The filament is disposed on an axis of the positive polar cylinder to form an activating space together with front end surfaces of the vanes and emit thermions. The upper and lower shields cover a top and bottom of the filament, respectively. The upper and lower pole pieces are spaced apart from the upper and lower shields, respectively, to induce magnetic flux in the activating space. In the present invention, the upper shield has a bottom surface formed to be entirely protruded downwardly, and the lower shield has a top surface formed to be entirely protruded upwardly.
    Type: Application
    Filed: November 25, 2002
    Publication date: February 5, 2004
    Applicant: Samsung Electronics Co., Ltd.
    Inventors: Jong-Chull Shon, Boris V. Rayskiy, Chul Kim, Hyun-Jun Ha
  • Publication number: 20010052825
    Abstract: A magnetron has an output comprising a coaxial line 15 which transmits energy from a wanted oscillator mode as a first coaxial waveguide mode and energy from an unwanted oscillator mode as a second cylindrical waveguide mode. Energy in the cylindrical waveguide mode is intercepted by slots 17, 18 in the coaxial line 15 and absorbed by material 19. This enables the modes to be separated. Preferably, the output is taken from the axis of the magnetron and the wanted oscillator mode in the &pgr;-1 mode.
    Type: Application
    Filed: March 8, 2001
    Publication date: December 20, 2001
    Inventors: Kesar Saleem, Alan Hugh Pickering, Michael Barry Clive Brady
  • Patent number: 5767749
    Abstract: A microwave oscillator with an M-type interdigital slow wave resonator structure is disclosed. In the above oscillator, the anode has top, middle and bottom resonance discs. The top disc has downward extending vanes and defines an upper resonance chamber, while the bottom disc has upward extending vanes and defines a lower resonance chamber. The upper and lower resonance chambers is separated from each other by a middle resonance disc that has upward and downward extending vanes. An emitter is placed between the filament and the anode and emits thermions into the actuating space when it is heated by the filament. The upward extending vanes of the middle disc engage with the vanes of the top disc in the type of interdigital engagement like clasped hands. The downward extending vanes of the middle disc engage with the vanes of the bottom disc in the same manner.
    Type: Grant
    Filed: October 18, 1996
    Date of Patent: June 16, 1998
    Assignee: Samsung Electronics Co., Ltd.
    Inventors: Jong-Chul Shon, Mark Ivanovich Kouznetsov, Sang-Gweon Kim
  • Patent number: 5676873
    Abstract: There is provided a magnetron comprising a cold cathode having an electron emitting member which is formed linearly or as a plane on a substrate to emit electrons a subdivided anode disposed oppositely in parallel with the electron emitting member, the subdivided anode having cavity resonators formed therein at the side of the cold cathode, and a magnet which producing a magnetic field lying at right angles to an electric field applied between the cold cathode and the subdivided anode. There is also provided a microwave oven for dielectric-heating a substance to be heated by using the magnetron as a microwave supply source.
    Type: Grant
    Filed: June 21, 1995
    Date of Patent: October 14, 1997
    Assignee: Sharp Kabushiki Kaisha
    Inventors: Takeo Takase, Masao Urayama, Terutaka Tokumaru, Minoru Makita, Seiki Yano
  • Patent number: 5162698
    Abstract: A cascaded magnetron device has an elongate cathode shank extending along its axis and a series of tubular anode elements placed end to end in a linear cascade surrounding the cathode shank along at least part of its length. Each adjacent pair of anode elements is separated by a conductive, annular pin down disc, and the cathode shank has a series of spaced bands of field emitting material separated by non-emitting regions, each band being located within a respective one of the anode elements and spaced inwardly from the ends of that element. Suitable power inputs and magnetic field generators are provided for generating electron emission and oscillation in the interaction zone between each emitting band and the anode element surrounding that band, and suitable extraction devices are provided for extracting power from each of the interaction zones, the arrangement producing phase-locking of the cascaded magnetron bodies.
    Type: Grant
    Filed: December 21, 1990
    Date of Patent: November 10, 1992
    Assignee: General Dynamics Corporation Air Defense Systems Div.
    Inventors: Keith Kato, James Weatherall
  • Patent number: 5159241
    Abstract: A relativistic magnetron device comprising an elongate cathode shank extending along the axis of the device and a cylindrical anode surrounding the cathode shank along at least part of its length to define an annular interaction area. The anode has an even number of resonator cavities facing the cathode, and microwave extraction devices are connected to alternate resonator cavities to extract power from the device. The cathode has a central, emission band extending from the center of the interaction area in opposite directions and terminating short of the ends of the anode, while the remainder of the cathode is non-emitting.
    Type: Grant
    Filed: October 25, 1990
    Date of Patent: October 27, 1992
    Assignee: General Dynamics Corporation Air Defense Systems Division
    Inventors: Keith G. Kato, James C. Weatherall
  • Patent number: 5113154
    Abstract: A microwave generator that uses an electron beam and the phenomenon of the oscillating virtual cathode, but makes it possible to obtain energy with improved spectral quality and conversion efficiency as compared with standard vircator generators. This is achieved by the separate use of the electrons coming from the virtual cathode (80), that is, transmitted electrons (80) or reflected electrons (81) to convert their kinetic energy into microwave energy (4).
    Type: Grant
    Filed: October 17, 1990
    Date of Patent: May 12, 1992
    Assignee: Thomson-CSF
    Inventors: Guy Convert, Jean-Pierre Brasile
  • Patent number: 5045814
    Abstract: A high impedance circuit has radially disposed first vanes and radially disposed second vanes interdigitating between the first vanes. The first vanes and the second vanes are each interconnected by a first toroidal strap and a second toroidal strap, respectively. The first strap and the second strap are dipsosed co-axially on opposite sides of the vane structure. The vanes and straps are dimensioned so that the circuit has a single cavity impedance commensurate with a predetermined interaction impedance for the oscillator which is sufficient to sustain oscillation for a preselected injection locking bandwidth of the oscillator.
    Type: Grant
    Filed: March 14, 1990
    Date of Patent: September 3, 1991
    Assignee: Litton Systems, Inc.
    Inventors: Robert C. English, Geoffrey Thornber, Christopher M. Walker
  • Patent number: 5043680
    Abstract: A magnetron is powered via an output transformer TR whose primary winding (a) is connected in series with a resonant converter oscillator circuit comprising an inductor (L) and a capacitor (C3) and switching transistors (T.sub.1, T.sub.2) which are connected to positive and negative power supply terminals and are switched by respective current transformers (CT1, CT2). The switching points of the switching transistors are varied so as to vary the output of the circuit by varying the positive and negative flux excursions in the cores of the transformers (CT1, CT2) such that the net flux excursions are sufficient to saturate the transformers and switch off the switching transistors at a predetermined point in each half cycle. The relative positive and negative flux excursions in the transformer cores are controlled by providing additional windings (g) which are connected to a control circuit whcih rectifies the output of these windings and controls the rectified DC voltage appearing across them.
    Type: Grant
    Filed: March 29, 1990
    Date of Patent: August 27, 1991
    Assignee: Aktiebolaget Electrolux
    Inventor: David Gurwicz
  • Patent number: 5021713
    Abstract: A magnetron in which a choke for preventing leakage of harmonic components of leaking microwaves to the outside of the tube is formed by a metal piece with slots that is placed within the tube or a conductive film that is placed on an insulating area of the stem.
    Type: Grant
    Filed: April 14, 1989
    Date of Patent: June 4, 1991
    Assignee: Matsushita Electronics Corporation
    Inventors: Kaoru Uesawa, Yoshio Abe
  • Patent number: 4988956
    Abstract: In a peniotron, a hollow electron beam is generated from a cathode gun assembly and a DC magnetic field is applied to the electron beam from solenoid coils. Thus, each electron of the electron beam is gyrated into a resonant cavity and into propagating waveguide sections which are maintained in auto-resonant conditions so that the electrons interact with an electromagnetic waves of TE mode not only in the resonant cavity section but also in a waveguide section. Accordingly, the electromagnetic wave is oscillated in the resonant waveguide section and amplified in the propagating waveguide section in such a manner that the level of the electromagnetic wave in the resonant cavity section is far less than the output power from said propagating waveguide.
    Type: Grant
    Filed: October 27, 1989
    Date of Patent: January 29, 1991
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Shoichi Ono, Kuniyoshi Yokoo, Tadashi Okamoto
  • Patent number: 4873408
    Abstract: A microwave oven uses a full wave full bridge inverter for supplying energy to a cooking magnetron by way of a power transformer. The inverter is controlled by a microprocessor which acts upon a control circuit having an oscillator. Two feedback loops are provided for controlling the operation of the magnetron. A relatively slow feedback loop uses the microprocessor to adjust inverter operation in order to stabilize the magnetron power output. A relatively fast feedback loop senses current passing through a primary of a power transformer. A signal based on the sensed current is provided to a comparator and compared to a reference. If the signal from the current sensor indicates that the current has become excessive, the comparator generates a shutdown signal which will stop the generation of gating pulses to the transistor switches of the inverter.
    Type: Grant
    Filed: December 28, 1987
    Date of Patent: October 10, 1989
    Assignee: General Electric Company
    Inventors: Pamela S. Smith, Peter H. Smith, deceased
  • Patent number: 4820688
    Abstract: Microwave oscillators and amplifiers which utilize a superconducting slow-wave circuit. The slow circuit is made from materials which exhibit superconductivity at relatively high critical temperatures. The slow wave circuit is integral with the device's vacuum housing. Coolant exterior to the vacuum housing maintains the circuit in the superconducting state. The slow-wave circuit, which protrudes into the vacuum housing provides modulation of an electron beam which traverses the interior of the vacuum housing. Output power is ultimately extracted from the slow wave circuit.
    Type: Grant
    Filed: November 27, 1987
    Date of Patent: April 11, 1989
    Inventor: Louis J. Jasper, Jr.
  • Patent number: 4785261
    Abstract: A magnetically insulated transmission line oscillator employs self-generated magnetic fields to generate microwave energy. An anode of the oscillator includes slow-wave structures which are formed of a plurality of thin conductive vanes defining cavities therebetween, and a gap is formed between the anode and a cathode of the oscillator. In response to a pulsed voltage applied to the anode and cathode, self-generated magnetic fields arfe produced in a cross-field orientation with respect to the orientation of the electric field between the anode and the cathode. The cross-field magnetic fields insulate the flow of electrons in the gap and confine the flow of electrons within the gap.
    Type: Grant
    Filed: May 19, 1987
    Date of Patent: November 15, 1988
    Assignee: The United States of America as represented by the United States Department of Energy
    Inventors: Larry D. Bacon, William P. Ballard, M. Collins Clark, Barry M. Marder
  • Patent number: 4752720
    Abstract: A magnetron with a filter case housing a through-type capacitor and a choke coil wherein a mounting plate for the capacitor is fixed in intimate contact with the wall of the filter case along a line encircling a through-hole drilled in the wall of the filter case for drawing out the terminals of the capacitor.
    Type: Grant
    Filed: December 10, 1985
    Date of Patent: June 21, 1988
    Assignee: Hitachi, Ltd.
    Inventors: Tomokatsu Oguro, Mamoru Tsuzurahara
  • Patent number: 4730170
    Abstract: A microwave generator is provided for generating microwaves substantially from virtual cathode oscillation. Electrons are emitted from a cathode and accelerated to an anode which is spaced apart from the cathode. The anode has an annular slit therethrough effective to form the virtual cathode. The anode is at least one range thickness relative to electrons reflecting from the virtual cathode. A magnet is provided to produce an optimum magnetic field having the field strength effective to form an annular beam from the emitted electrons in substantial alignment with the annular anode slit. The magnetic field, however, does permit the reflected electrons to axially diverge from the annular beam. The reflected electrons are absorbed by the anode in returning to the real cathode, such that substantially no reflexing electrons occur. The resulting microwaves are produced with a single dominant mode and are substantially monochromatic relative to conventional virtual cathode microwave generators.
    Type: Grant
    Filed: March 31, 1987
    Date of Patent: March 8, 1988
    Assignee: The United States of America as represented by the Department of Energy
    Inventors: Thomas J. T. Kwan, Charles M. Snell
  • Patent number: 4668924
    Abstract: A crossed-field microwave power tube. Electrons are emitted from a tubular lectrode at ground potential. The electrons are accelerated by an electric field toward a high voltage anode located within the tubular electrode. A magnetic field is oriented along the axis of the tube; the magnetic field is perpendicular to the electric field. The electrons follow curved paths in the space between the tubular electrode and the anode, while producing electromagnetic radiation in a TEM mode. The TEM radiation is easily coupled from the tube.
    Type: Grant
    Filed: August 19, 1986
    Date of Patent: May 26, 1987
    Assignee: The United States of America as represented by the Secretary of the Army
    Inventor: Brett D. van de Sande
  • Patent number: 4628284
    Abstract: A push-pull current-fed parallel resonant oscillator includes a parallel resonant LC tank circuit with one end coupled to one terminal of a DC current source via a serially connected first diode and first switching transistor and the other end of the tank circuit coupled to said one terminal via a serially connected second diode and second switching transistor. Respective capacitors (17, 21) shunt the series connections. The tank circuit inductor includes the primary of a transformer whose secondary is part of the transistor drive circuit. The circuit parameters are chosen to provide a duty cycle less than 50% and a high voltage gain of the AC tank voltage. The transistors are controlled to delay the turn-off time of the on-transistor thereby allowing a negative voltage to develop on the opposite capacitor which in turn delays turn-off of its parallel connected transistor so as to provide a dead-time (.DELTA.t.sub.2) during the switching interval in which both transistors are simultaneously off.
    Type: Grant
    Filed: June 3, 1985
    Date of Patent: December 9, 1986
    Assignee: North American Philips Corporation
    Inventors: Gert W. Bruning, Mark W. Fellows
  • Patent number: 4588965
    Abstract: A coaxial magnetron has a high-Q resonant cavity surrounding a multiple-resonator anode circuit and coupled by slots to alternate anode resonators. The cavity is resonant in the TE.sub.111 mode, having two zero points of electric field on its periphery. The anode circuit is correspondingly resonant in its N/2-1 mode.Mode suppression means damp out the degenerate TE.sub.111 mode which is not coupled to the output iris.The size and weight of the magnetron are much less than conventional tubes using a cavity resonant in the TE.sub.011 mode with circular electric field.
    Type: Grant
    Filed: June 25, 1984
    Date of Patent: May 13, 1986
    Assignee: Varian Associates, Inc.
    Inventor: Alfred W. Cook
  • Patent number: 4555680
    Abstract: A resonant-cavity type electronic tube having mechanically-operable tuning vanes associated with its resonant-cavity structure and disposed within an evacuable envelope. A support member is provided within the envelope for adjusting the tuning vanes relative to the resonant-cavity structure, so as to tune the frequency of resonance of the structure step-wise in accordance with a predetermined program. The tuning is carried out with a step motor, having a stator and armature with the envelope having a portion extending between the stator and armature for enclosing the armature within the evacuable space containing the tuning vanes and the resonant cavity structure. The armature is coupled to the tuning vanes for altering the position thereof relative to the resonant-cavity structure in fixed relation to the displacement of the armature relative to the stator. Electrical signals are coupled to the stator for establishing a programmable series of displacements of the armature relative to the stator.
    Type: Grant
    Filed: July 5, 1983
    Date of Patent: November 26, 1985
    Assignee: M/A-COM, Inc.
    Inventor: John E. Burr
  • Patent number: 4517430
    Abstract: A heating device for use in laboratories and the like comprising an oven housing having a magnetron tube, power control circuitry for the magnetron tube, a timer for determining an amount of pulse power for the magnetron tube, a settable heating time switch with display, a settable venting time switch and display, and magnetron tube resistance heating structure directly, physically attached thereto with thermostatic control therefore for accurately, and by a predetermined amount, heating the magnetron tube prior to operation of the overall heating device. Because the temperature of the magnetron tube is very accurately maintained all of the changeable operating controls for the magnetron respond predictably and with a high degree of accuracy, and therefore when the heating device is used in laboratory applications for heating and drying a plurality of samples individually, each sample can be predeterminedly heated and dryed in a predicable manner like the previous samples.
    Type: Grant
    Filed: May 10, 1983
    Date of Patent: May 14, 1985
    Assignee: GCA Corporation
    Inventor: Mark J. Slottag
  • Patent number: 4482870
    Abstract: In a magnetron of the type wherein a gasket member in the form of a fine metal wire net is disposed between a cup shaped sealing member on the output side, and a magnetic yoke providing a magnetic flux passage for permanent magnets contained in the magnetic yoke, a portion of the yoke is provided with an annular projection for snugly receiving the gasket member and a flat edge integral with the projection is provided between the annular projection and the cup shaped sealing member for supporting the gasket member.
    Type: Grant
    Filed: October 19, 1981
    Date of Patent: November 13, 1984
    Assignee: Hitachi, Ltd.
    Inventor: Masao Sakai
  • Patent number: 4481447
    Abstract: A method of controlling the power output of a magnetron tube, and an electric power supply for supplying power to the tube. According to the method, power is continuously supplied to the magnetron heater. At the same time, a voltage is continuously applied across the anode and the cathode of the tube. This voltage across the anode and the cathode varies in cycles between a first value, which is substantially at or below the threshold voltage of the magnetron tube, and a second value, which is above the threshold voltage. The average magnetron power output is determined by the proportion of each cycle during which the voltage across the anode and the cathode is above the threshold voltage.
    Type: Grant
    Filed: June 21, 1982
    Date of Patent: November 6, 1984
    Assignee: U.S. Philips Corporation
    Inventors: Edward H. Stupp, Mark W. Fellows
  • Patent number: 4480234
    Abstract: A gyrotron backward wave oscillator device is described which can be operated in a controlled and predictable manner. The device includes an evacuated waveguide section, an electron source at one end providing a spiral electron beam, a collector at the opposite end, means for producing a magnetic field parallel to the longitudinal axis of the waveguide section, and an output window, the parameters of the device being such as to support backward wave oscillation therein and to output same through the window.
    Type: Grant
    Filed: September 18, 1981
    Date of Patent: October 30, 1984
    Assignee: Elta Electronics Industries Ltd.
    Inventor: Jonathan M. Wachtel
  • Patent number: 4419606
    Abstract: A magnetron has a filter circuit inserted in a feeder line to a cathode electrode included in a high frequency generator and comprised of choke coils and a capacitor connected in series, in order to suppress leakage of unwanted high frequency components from the cathode electrode. At least one of the choke coils has an air-core coarse coil winding close to the cathode electrode which has at least two turns and a remainder of fine coil winding wound about a ferrite core, so that burning of the choke coil and overheating of the ferrite core can readily be prevented without imparing the function to suppress unwanted high frequency component leakage.
    Type: Grant
    Filed: June 1, 1981
    Date of Patent: December 6, 1983
    Assignee: Hitachi, Ltd.
    Inventors: Mamoru Tsuzurabara, Seiji Kitakaze
  • Patent number: 4356431
    Abstract: Microwave oven with a self-regulating circuit operated from a low voltage a.c. source based upon a substantially constant current transformer and condenser series combination and having a return path for current on alternate half cycles. For defrosting food the magnetron is operated at partial power which is achieved by decreasing the voltage applied to the magnetron. This is done either by increasing the capacitive reactance in series with the secondary of the transformer or by decreasing the secondary voltage. Switching problems are solved by providing the arrangement of the invention at the grounded end of the transformer secondary. The self-regulating circuit is required to be of the type which has one end of the secondary winding grounded.
    Type: Grant
    Filed: February 21, 1978
    Date of Patent: October 26, 1982
    Assignee: Advance Transformer Company
    Inventor: Albert E. Feinberg
  • Patent number: 4302651
    Abstract: An SCR circuit is provided in a high-voltage supply for energizing a magnetron that is assembled in a microwave oven. The high-voltage supply circuit includes a voltage step-up transformer. This transformer is arranged with a low-voltage secondary winding which is connected across the heater-cathode electrode of the magnetron and a high-voltage secondary winding which is coupled in series with a capacitor. The series combination of the capacitor and the high-voltage secondary is connected across the cathode and anode electrodes of the magnetron; and importantly, the high-voltage SCR circuit includes a number of series-connected SCR's electrically in shunt of the magnetron. A triggering circuit gates the high-voltage SCR circuit to the current-conducting state during a selected phase portion of an applied AC potential, in order to control the amount of power being supplied to the magnetron.
    Type: Grant
    Filed: June 21, 1979
    Date of Patent: November 24, 1981
    Assignee: Varo Semiconductor, Inc.
    Inventor: Walter L. Wills
  • Patent number: 4288721
    Abstract: A microwave magnetron-type device comprises an anode assembly or block in the form of a multistage two-dimensional periodic retarding system, including cavities with vanes, each having a lumped inductance portion defined by the vane sidewalls near the vane bases, and straps. The straps are arranged on each stage of the retarding system and pass through windows made in the vanes. Provided in the inductive portion of the cavities of the retarding system is at least one duct with the following ratios:d.sub.1 >d.sub.2 >d.sub.3,d.sub.3 >d.sub.4 >d.sub.5,h.sub.1 .ltoreq.h.sub.2,where d.sub.1 is the distance between the vane ends and the outer surface of the anode assembly, d.sub.2 is the distance between the vane ends and the duct wall adjacent to the outer surface of the anode assembly, d.sub.3 is the distance between the vane ends and the wall of the inductive portion of the cavities, remotest from the vane ends, d.sub.4 is the distance between the vane ends and the opposite duct wall, d.sub.
    Type: Grant
    Filed: June 20, 1979
    Date of Patent: September 8, 1981
    Inventor: Jury I. Dodonov
  • Patent number: 4268779
    Abstract: A circuit for controlling power consumption of a load, by controlling the flow of current thereto, utilizes at least one parallel combination of non-linear resistance elements, such as a varistor and the like, and a gateable semiconductor switching device, such as a triac and the like, to substantially reduce or prevent current flow when the semiconductor switching device is gated to an "off" condition and to enable normal current flow to a load when the semiconductor switching device is gated to an "on" condition. Embodiments of the power circuits for control of magnetron power, in a microwave oven, are illustrated.
    Type: Grant
    Filed: August 13, 1979
    Date of Patent: May 19, 1981
    Assignee: General Electric Company
    Inventors: Charles W. Eichelberger, Rudolph A. Dehn, Michael Gdula, Robert J. Wojnarowski
  • Patent number: 4175246
    Abstract: A magnetron energizing circuit preferably uses two transformers of the high leakage reactance type having isolated secondaries with an end terminal of each secondary connected to a common point which is at ground potential. The secondaries are connected to series condensers in two loops which provide leading current flowing in the secondaries at all times while both are connected in the circuit to produce saturation in the respective cores of the secondaries whereby to achieve substantially constant current and good regulation for variations in the primary voltage. A single magnetron is served by the circuit and variations in the loading of the magnetron are also compensated for by virtue of the substantially constant current circuit. The secondaries are connected in opposite phase with respect to the respective capacitors which they serve to charge to obtain a full wave doubler operation when the transformers are both in circuit but with low peak current.
    Type: Grant
    Filed: February 27, 1978
    Date of Patent: November 20, 1979
    Assignee: Advance Transformer Company
    Inventors: Albert E. Feinberg, Kenneth Woo
  • Patent number: 4164685
    Abstract: A magnetron device emits through the filament terminals electromagnetic waves of a broad frequency band which act as noises to other electronic devices. The magnetron device comprises a filament or heater circuit for supplying heater voltage to the filament to emit thermal electrons from the cathode and an anode circuit for applying a required voltage across the filament and anode. The filament circuit is connected to one secondary winding of a power supply transformer and the anode circuit to the other secondary winding thereof. Connected to the anode power supply line is a filter device comprising a capacitor and a choking element having a sufficient inductance to reduce a relatively low frequency of the broad frequency band. This filter device is intended to reduce or suppress a large amount of the noise transmitted to the anode circuit out of a magnetron through filament terminals.
    Type: Grant
    Filed: September 13, 1977
    Date of Patent: August 14, 1979
    Assignee: Tokyo Shibaura Electric Co., Ltd.
    Inventor: Hirokazu Takahashi
  • Patent number: 4017702
    Abstract: Apparatus for varying microwave power level is included in a microwave oven. The microwave oven includes a magnetron for producing microwaves used for heating and a half-wave voltage doubler for supplying half-wave pulsating DC voltage to the magnetron. In order to vary voltage and thus power output of the magnetron, the charging of the capacitor in the half-wave voltage doubler is controlled by a variable resistance connected in series with the rectifier in the otherwise conventional half-wave voltage doubler.
    Type: Grant
    Filed: July 30, 1975
    Date of Patent: April 12, 1977
    Assignee: General Electric Company
    Inventors: Larry R. Harmon, Donald J. Simon
  • Patent number: 4012617
    Abstract: A power supply for a microwave magnetron includes a transformer having a secondary winding, a capacitor connected to one end of the winding, a magnetron connected in between the remaining end of the capacitor and the winding so as to form a first unidirectional current conducting path capable of conducting current in one direction and a second circuit connected in shunt of the magnetron having unidirectional current conduction characteristics and being switchable to an On or Off condition, said second circuit being electrically poled opposite to the polarity of the magnetron and means for controlling the switching of the second circuit to its current conducting condition as a function of the magnitude of current through the magnetron.
    Type: Grant
    Filed: July 24, 1975
    Date of Patent: March 15, 1977
    Assignee: Litton Systems, Inc.
    Inventors: Robert Virgil Burke, Thomas Eugene Hester
  • Patent number: 4001537
    Abstract: A microwave magnetron operating circuit includes a high leakage reactance transformer having a secondary winding a capacitor connected in series with the secondary winding and means connecting the series combination of capacitor and secondary winding across heater cathode and anode terminals of a magnetron. A controlled semi-conductor switch such as a triac is connected electrically in shunt of the magnetron. Control means are provided to operate the triac to its current conducting state so as to conduct current in shunt of the magnetron. The control means includes a positionable control member, accessible to the user, for varying the time at which the controlled semi-conductor device is placed in its electrically conductive state so as to permit the user to adjust or set the power supplied to the magnetron to various different power levels.
    Type: Grant
    Filed: July 24, 1975
    Date of Patent: January 4, 1977
    Assignee: Litton Systems, Inc.
    Inventors: Robert Virgil Burke, Thomas Eugene Hester
  • Patent number: 3982152
    Abstract: A crossed-field device having a plurality of slow wave energy propagating structures, each with an associated cathode, requires relatively low voltage for operation to provide a high power output. Electron beam current control is achieved by means of RF drive signals. Periodic permanent magnet focusing is utilized.
    Type: Grant
    Filed: November 25, 1974
    Date of Patent: September 21, 1976
    Assignee: Raytheon Company
    Inventor: William A. Smith
  • Patent number: RE34863
    Abstract: A high impedance circuit has radially disposed first vanes and radially disposed second vanes interdigitating between the first vanes. The first vanes and the second vanes are each interconnected by a first toroidal strap and a second toroidal strap, respectively. The first strap and the second strap are disposed co-axially on opposite sides of the vane structure. The vanes and straps are dimensioned so that the circuit has a single cavity impedance commensurate with a predetermined interaction impedance for the oscillator which is sufficient to sustain oscillation for a preselected injection locking band-width of the oscillator.
    Type: Grant
    Filed: June 25, 1993
    Date of Patent: February 21, 1995
    Assignee: Litton Systems, Inc.
    Inventors: Robert C. English, Geoffrey Thornber, Christopher M. Walker