Patents Assigned to NEC Microwave Tube, Ltd.
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Publication number: 20130259089Abstract: A temperature detection apparatus includes a transformer, a thermostat attached directly to an electrically conductive site of the heating element and has contacts that become short-circuited or come into an open-circuit condition depending on whether or not the temperature of the heating element is equal to or higher than a predetermined value, the contacts being connected to a secondary coil in the transformer, a DC voltage source and a transistor configured to supply required AC power to a primary coil in the transformer, a current detection resistor configured to detect a current flowing through the primary coil in the transformer, and a comparison circuit detecting a voltage generated across the current detection resistor when a current flows through the current detection resistor, the comparison circuit outputting an alarm signal when the current flowing through the primary coil in the transformer exceeds a preset threshold current.Type: ApplicationFiled: May 29, 2013Publication date: October 3, 2013Applicant: NEC MICROWAVE TUBE, LTD.Inventors: YUKIHIRA NAKAZATO, JUNICHI MATSUOKA
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Patent number: 8491187Abstract: A temperature detection apparatus includes a transformer, a thermostat attached directly to an electrically conductive site of the heating element and has contacts that become short-circuited or come into an open-circuit condition depending on whether or not the temperature of the heating element is equal to or higher than a predetermined value, the contacts being connected to a secondary coil in the transformer, a DC voltage source and a transistor configured to supply required AC power to a primary coil in the transformer, a current detection resistor configured to detect a current flowing through the primary coil in the transformer, and a comparison circuit detecting a voltage generated across the current detection resistor when a current flows through the current detection resistor, the comparison circuit outputting an alarm signal when the current flowing through the primary coil in the transformer exceeds a preset threshold current.Type: GrantFiled: October 5, 2009Date of Patent: July 23, 2013Assignee: NEC Microwave Tube, Ltd.Inventors: Yukihira Nakazato, Junichi Matsuoka
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Patent number: 8212481Abstract: A voltage control apparatus used for an electron tube or a power supply apparatus includes a detecting circuit for detecting current flowing through a helix electrode, a voltage-limiting circuit for controlling a potential difference between the helix electrode and the anode electrode based on a predetermined voltage level; and a switch for switching based on an output from the detecting circuit. The switch connects the helix electrode and the anode electrode through the voltage-limiting circuit, or causes a short circuit between the helix electrode and the anode electrode.Type: GrantFiled: March 2, 2009Date of Patent: July 3, 2012Assignee: NEC Microwave Tube, LtdInventor: Yukihira Nakazato
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Patent number: 8027182Abstract: An electric current measurement apparatus for measuring an electric current of each electrode of an electron tube includes a transformer, a detection resistor connected in an ampere meter route for measurement, a voltage detection unit for detecting electric potential difference of the detection resistor and outputting pulse signals corresponding to the detected electric potential difference, a switching part for providing a short circuit of the secondary winding according to the pulse signals, and a measurement current value output unit. The measurement current value output unit measures pulse attribute of pulse-shape signals which are induced on the primary winding of the transformer caused by the short circuit of the secondary winding, and outputs a value of electric current flowing through the detection resistor with referring to a predetermined relationship between a value of the electric current flowing through the detection resistor and the pulse signals generated in the voltage detection unit.Type: GrantFiled: March 12, 2009Date of Patent: September 27, 2011Assignee: NEC Microwave Tube, Ltd.Inventor: Shuji Abiko
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Patent number: 7952288Abstract: The present invention includes a Zener diode connected between a helix electrode and an anode electrode, a transistor that closes or opens a circuit between a cathode and an anode of the Zener diode, a photocoupler for turning ON/OFF the transistor through a phototransistor, a first switch for supplying or cutting off a DC voltage for the photodiode of the photocoupler, a capacitor to which the DC voltage that is to be supplied to the photodiode is applied and a control unit that turns ON the first switch beforehand to apply a DC voltage to the photocoupler and the capacitor and that turns OFF the first switch simultaneously with an application of a helix voltage.Type: GrantFiled: October 10, 2008Date of Patent: May 31, 2011Assignee: NEC Microwave Tube, Ltd.Inventor: Yukihira Nakazato
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Patent number: 7764025Abstract: A power supply apparatus has a series regulator for generating a predetermined power supply voltage from a DC voltage output from the rectifying circuit, and a capacitor bank of rectifying capacitors for stabilizing the power supply voltage. The power supply apparatus also has a charging bypass circuit connected between input and output terminals of the series regulator. The charging bypass circuit is turned on or off by an externally supplied drive signal, When a drop of the power supply voltage is detected, the charging bypass circuit is turned on.Type: GrantFiled: May 29, 2007Date of Patent: July 27, 2010Assignee: NEC Microwave Tube, Ltd.Inventor: Junichi Kobayashi
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Patent number: 7719196Abstract: The present invention includes a waveguide for outputting radio frequency wave, a vacuum envelope provided with a slow-wave circuit, a coaxial connection part connecting the waveguide and the vacuum envelope, an insulating window member which is provided in the coaxial connection part and which hermetically seals a said of vacuum envelope and a said of waveguide, a coaxial center conductor of exterior portion with one end supported by the waveguide, and a coaxial center conductor of an interior portion with one end abutting on the slow-wave circuit and the other end connected to the coaxial center conductor of the exterior portion. The waveguide is provided with a screw part supporting the coaxial center conductor of the exterior portion movably in an axial direction of the coaxial center conductor of the exterior portion.Type: GrantFiled: April 8, 2008Date of Patent: May 18, 2010Assignee: NEC Microwave Tube, Ltd.Inventor: Koji Okamoto
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Patent number: 7688163Abstract: A pillbox vacuum window of the present invention has a first metal part and a second metal part. The first metal part includes a ceramic disk formed with a metallization layer in a peripheral area thereof, a larger diameter cylindrical portion, and a smaller diameter cylindrical portion having an inner diameter smaller than that of the larger diameter cylindrical portion, and coupled to the larger diameter cylindrical portion to form a step section at a joint, where the ceramic disk is fitted into the step section. The second metal part includes a cylindrical portion, where the cylindrical portion is inserted into the step section of the first metal part while the ceramic disk is placed in the step section of the first metal part.Type: GrantFiled: April 11, 2007Date of Patent: March 30, 2010Assignee: NEC Microwave Tube, Ltd.Inventor: Tetsuo Machida
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Patent number: 7652392Abstract: The present invention includes: a transformer; a primary source for supplying an alternating voltage of at least two frequencies to a primary winding of the transformer; and a filter circuit connected to a secondary winding of the transformer and having an attenuation that varies according to the frequency of the alternating voltage, where the frequency of the alternating voltage supplied to the primary winding of the transformer is controlled so that a desired alternating voltage is outputted from the filter circuit connected to the secondary winding of the transformer.Type: GrantFiled: August 6, 2007Date of Patent: January 26, 2010Assignee: NEC Microwave Tube, Ltd.Inventor: Yukihira Nakazato
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Patent number: 7589469Abstract: A coaxial waveguide converter circuit is provided for converting an input/output coaxial section of a traveling-wave tube to a waveguide. The circuit comprises a waveguide matching part for connecting an inner conductor of the coaxial section extending into the waveguide to a wall of the waveguide. The waveguide matching part includes a fitting hole for fitting the inner conductor thereinto, and a plurality of cantilever supports which define the fitting hole at leading end portions thereof. The leading end portions of the plurality of cantilever supports defining the fitting hole are uniformly kept in close contact with a peripheral surface of the inner conductor.Type: GrantFiled: July 18, 2007Date of Patent: September 15, 2009Assignee: NEC Microwave Tube, Ltd.Inventors: Kazuhito Soga, Akihiko Nemoto
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Patent number: 7489084Abstract: A power supply apparatus for supplying predetermined supply voltages respectively to an anode electrode, a cathode electrode, a collector electrode, and a helix of an electron tube. The power supply apparatus comprises an anode switch for turning on/off the anode voltage output, and an anode switch control circuit for controlling the on/off operation of the anode switch such that a pulsed anode voltage is repeatedly applied to the anode electrode a plurality of times at a predetermined period when operation of a helix power supply and a collector power supply is stopped.Type: GrantFiled: January 30, 2007Date of Patent: February 10, 2009Assignee: NEC Microwave Tube, Ltd.Inventors: Junichi Kobayashi, Eiji Fujiwara
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Publication number: 20090033228Abstract: A power supply apparatus for a traveling-wave tube includes an electrical discharge switch and a first resistor that are serially connected, and that are connected between a cathode electrode and a first collector electrode; N (N denotes a positive integer) arresters that are serially connected, and that are inserted between a ground potential and a connection node of the electrical discharge switch and the first resistor; N second resistors that are inserted between the N arresters and a second collector electrode to an Nth collector electrode and a ground potential, respectively; and an electrical discharge control circuit that turns off the electrical discharge switch at a time of normal operation of the power supply apparatus and turns on the electrical discharge switch when stopping operation of the power supply apparatus.Type: ApplicationFiled: July 30, 2008Publication date: February 5, 2009Applicant: NEC Microwave Tube, Ltd.Inventors: Junichi KOBAYASHI, Yukihira NAKAZATO
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Publication number: 20090009086Abstract: A bottom portion of a metal tape is attached to an end portion of a helix. A coaxial inner conductor for input or output of a high frequency signal is fixed by its end portion being interposed between upright surfaces of the metal tape. The metal tape is joined to the coaxial inner conductor by being laser-welded to opposite side surfaces of the coaxial inner conductor.Type: ApplicationFiled: July 3, 2008Publication date: January 8, 2009Applicant: NEC MICROWAVE TUBE, LTDInventors: Kazuhito SOGA, Akira CHIBA
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Publication number: 20080246553Abstract: The present invention includes a waveguide for outputting radio frequency wave, a vacuum envelope provided with a slow-wave circuit, a coaxial connection part connecting the waveguide and the vacuum envelope, an insulating window member which is provided in the coaxial connection part and which hermetically seals a said of vacuum envelope and a said of waveguide, a coaxial center conductor of exterior portion with one end supported by the waveguide, and a coaxial center conductor of an interior portion with one end abutting on the slow-wave circuit and the other end connected to the coaxial center conductor of the exterior portion. The waveguide is provided with a screw part supporting the coaxial center conductor of the exterior portion movably in an axial direction of the coaxial center conductor of the exterior portion.Type: ApplicationFiled: April 8, 2008Publication date: October 9, 2008Applicant: NEC MICROWAVE TUBE, LTD.Inventor: Koji Okamoto
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Publication number: 20080231197Abstract: At the time of restoration of the power supply after a power failure, a voltage higher than that in the normal operation mode is supplied to a heater. After a lapse of a predetermined time, the voltage to be supplied to the heater is switched into the voltage in the normal operation mode while a control signal for stating the operation of an electron tube is output. Alternatively, at the time of power activation, the rate of change of current flowing through a heater is determined for every period of time. When the rate of change becomes equal to or lower than a predetermined threshold, a voltage higher than that in the normal operation mode is supplied to the heater, and after a lapse of a predetermined time, the voltage to be supplied to the heater is switched into the voltage in the normal operation mode while a control signal for stating the operation of the electron tube is output.Type: ApplicationFiled: March 18, 2008Publication date: September 25, 2008Applicant: NEC MICROWAVE TUBE, LTD.Inventors: Akira CHIBA, Yukihira NAKAZATO
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Publication number: 20080054719Abstract: The present invention includes: a transformer; a primary source for supplying an alternating voltage of at least two frequencies to a primary winding of the transformer; and a filter circuit connected to a secondary winding of the transformer and having an attenuation that varies according to the frequency of the alternating voltage, where the frequency of the alternating voltage supplied to the primary winding of the transformer is controlled so that a desired alternating voltage is outputted from the filter circuit connected to the secondary winding of the transformer.Type: ApplicationFiled: August 6, 2007Publication date: March 6, 2008Applicant: NEC MICROWAVE TUBE, LTDInventor: Yukihira Nakazato
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Publication number: 20080024251Abstract: A coaxial waveguide converter circuit is provided for converting an input/output coaxial section of a traveling-wave tube to a waveguide. The circuit comprises a waveguide matching part for connecting an inner conductor of the coaxial section extending into the waveguide to a wall of the waveguide. The waveguide matching part includes a fitting hole for fitting the inner conductor thereinto, and a plurality of cantilever supports which define the fitting hole at leading end portions thereof. The leading end portions of the plurality of cantilever supports defining the fitting hole are uniformly kept in close contact with a peripheral surface of the inner conductor.Type: ApplicationFiled: July 18, 2007Publication date: January 31, 2008Applicant: NEC MICROWAVE TUBE, LTD.Inventors: Kazuhito SOGA, Akihiko Nemoto
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Patent number: 7315134Abstract: Control of an output pulse width by a PWM control circuit is stopped and the initial pulse string having a fixed pulse width is outputted in order to obtain a power supply voltage rise within a predetermined time period at the time of turning on the power. During normal operation, the voltage detected by a voltage detecting circuit is captured by a PWM control circuit, and the pulse width of the output pulse string is adjusted according to the detected voltage in order to keep the power supply voltage constant.Type: GrantFiled: November 10, 2004Date of Patent: January 1, 2008Assignee: NEC Microwave Tube, Ltd.Inventor: Junichi Matsuoka
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Publication number: 20070279009Abstract: A power supply apparatus has a series regulator for generating a predetermined power supply voltage from a DC voltage output from the rectifying circuit, and a capacitor bank of rectifying capacitors for stabilizing the power supply voltage. The power supply apparatus also has a charging bypass circuit connected between input and output terminals of the series regulator. The charging bypass circuit is turned on or off by an externally supplied drive signal, When a drop of the power supply voltage is detected, the charging bypass circuit is turned on.Type: ApplicationFiled: May 29, 2007Publication date: December 6, 2007Applicant: NEC MICROWAVE TUBE, LTD.Inventor: Junichi KOBAYASHI
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Publication number: 20070241845Abstract: A pillbox vacuum window of the present invention has a first metal part and a second metal part. The first metal part includes a ceramic disk formed with a metallization layer in a peripheral area thereof, a larger diameter cylindrical portion, and a smaller diameter cylindrical portion having an inner diameter smaller than that of the larger diameter cylindrical portion, and coupled to the larger diameter cylindrical portion to form a step section at a joint, where the ceramic disk is fitted into the step section. The second metal part includes a cylindrical portion, where the cylindrical portion is inserted into the step section of the first metal part while the ceramic disk is placed in the step section of the first metal part.Type: ApplicationFiled: April 11, 2007Publication date: October 18, 2007Applicant: NEC MICROWAVE TUBE, LTD.Inventor: Tetsuo MACHIDA