Patents by Inventor Masayuki Yasumura

Masayuki Yasumura has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Publication number: 20070081365
    Abstract: In the switching power supply circuit disclosed in the present invention, the DC voltage is supplied to the primary winding in the converter transformer and the AC voltage is generated. First and second series resonant circuit are formed, and the resonant frequency of the first and second series resonant circuits are set to be substantially equal to each other. A parallel resonant circuit is formed, and the resonant frequency of the parallel resonant circuit is set higher than the resonant frequencies of the first and second series resonant circuits. The secondary winding includes first and second secondary windings so that currents are extracted from the first and second secondary windings, respectively, and a ratio of the number of turns of the first secondary winding to that of the second secondary winding is defined so that magnitudes of the currents are substantially equal to each other.
    Type: Application
    Filed: August 23, 2006
    Publication date: April 12, 2007
    Applicant: Sony Corporation
    Inventor: Masayuki Yasumura
  • Publication number: 20070076443
    Abstract: A switching power supply circuit includes a switching element, a converter transformer, a secondary-side rectifying and smoothing circuit, a switching element control unit, a choke coil, a primary-side series resonant circuit, a primary-side parallel resonant circuit, and a series circuit. The switching element implements switching for a direct-current (DC) voltage to convert the voltage into an alternating-current (AC) voltage. The choke coil is supplied with the voltage and is connected to one winding end of the primary winding and one terminal of the switching element. The primary-side series resonant circuit connects a primary-side series resonant capacitor, having a resonant frequency dominated by a leakage inductance. The primary-side parallel resonant circuit connects a primary-side parallel resonant capacitor in parallel to the switching element, having a resonant frequency.
    Type: Application
    Filed: September 26, 2006
    Publication date: April 5, 2007
    Applicant: Sony Corporation
    Inventor: Masayuki Yasumura
  • Patent number: 7193868
    Abstract: A wide-range compatible voltage resonant converter provides high efficiency and allows use of low-breakdown-voltage products for a circuit. The voltage resonant converter is provided with a secondary-side parallel resonant circuit and a secondary-side series resonant circuit, and a loose coupling state is established in which the coupling coefficient of an isolation converter transformer is about 0.7 or less. Thus, a constant-voltage control characteristic is obtained as a sharp unimodal characteristic, which narrows the switching frequency control region required for stabilization of an output voltage. In addition, a primary-side parallel resonant frequency, a secondary-side parallel resonant frequency and a secondary-side series resonant frequency are set so that a favorable power conversion efficiency is obtained. Moreover, an active clamp circuit is provided to suppress the peak level of a resonant voltage pulse to thereby allow use of low-breakdown-voltage products for a switching element and so on.
    Type: Grant
    Filed: March 6, 2006
    Date of Patent: March 20, 2007
    Assignee: Sony Corporation
    Inventor: Masayuki Yasumura
  • Publication number: 20070035971
    Abstract: A switching power supply circuit includes a rectifier inputting and rectifying an alternating-current voltage to produce a rectified voltage; a smoothing unit smoothing the rectified voltage; a switching unit including a switching element operable to perform a switching operation; a switching drive unit operable to drive the switching element; an isolation converter transformer including primary and secondary windings with a coupling coefficient to obtain adequate zero voltage switching in an intermediate load condition; a primary-side parallel resonant circuit including a leakage inductance component and a capacitance of a primary-side parallel resonant capacitor to make the switching unit exhibit voltage resonant operation; a secondary-side series resonant circuit including a leakage inductance component and a capacitance of a secondary-side series resonant capacitor; a secondary-side direct-current output voltage producing unit producing a secondary-side direct-current output voltage by a rectifying operat
    Type: Application
    Filed: June 30, 2006
    Publication date: February 15, 2007
    Applicant: Sony Corporation
    Inventor: Masayuki Yasumura
  • Publication number: 20070024255
    Abstract: Enhancement of the power conversion efficiency and reduction of switching noise of a power supply circuit are achieved. The power supply circuit includes, on the primary side, a composite resonance type converter formed from a current resonance type converter and a partial voltage resonance circuit in combination, and is configured so as to produce a plurality of secondary side DC output voltages. A particular one of the plural secondary side DC output voltages is controlled to a constant voltage by variably controlling the switching frequency of a primary side switching converter. Each of the remaining secondary side DC output voltages is controlled to a constant voltage by adjusting the level of control current to be supplied to a controlling winding of a control transformer in response to the level of the secondary side DC output voltage to adjust the inductance of a controlling winding of the control transformer inserted in a rectification current path.
    Type: Application
    Filed: November 13, 2003
    Publication date: February 1, 2007
    Applicant: Sony Corporation
    Inventor: Masayuki Yasumura
  • Patent number: 7170761
    Abstract: A switching power supply circuit includes a primary side series resonant circuit forming a current resonant converter, and a secondary side series resonant circuit formed by at least a secondary winding and a secondary side series resonant capacitor, whereby a coupling type resonant circuit is formed by magnetic coupling of an isolated converter transformer. In order to obtain a unimodal characteristic for this coupling type resonant circuit, the total coupling coefficient of the isolated converter transformer is set to 0.65 or lower. For power factor improvement, a power factor improving circuit of a power regeneration system or a voltage feedback system is provided.
    Type: Grant
    Filed: June 2, 2005
    Date of Patent: January 30, 2007
    Assignee: Sony Corporation
    Inventor: Masayuki Yasumura
  • Patent number: 7167384
    Abstract: A switching power circuit in which a synchronous rectification circuit of the winding voltage detection system by use of a resistance device is provided on the secondary side of a compound resonance type converter, whereby a high power conversion efficiency can be obtained, and a reduction in the circuit scale through circuit simplification can be had. The gap length of an insulated converter transformer is enlarged to set the coupling coefficient at about 0.8, and the numbers of turns of the primary winding and the secondary windings are so set that the induced voltage level in the secondary winding is not more than 2 V/T. This causes the secondary-side rectified current to be in a continuous mode even under a heavy load condition by setting the magnetic flux density of the core in the insulated converted transformer to be not more than a predetermined value.
    Type: Grant
    Filed: August 13, 2004
    Date of Patent: January 23, 2007
    Assignee: Sony Corporation
    Inventor: Masayuki Yasumura
  • Patent number: 7158389
    Abstract: A switching power supply circuit having a power factor improving function that makes it possible to improve power conversion efficiency and reduce size and weight of the circuit. A complex resonant converter is formed by at least combining a current resonant converter of a half-bridge coupling system on a primary side with a partial resonant voltage circuit. Power factor improvement is made by performing voltage feedback of a switching output of the complex resonant converter to a rectification current path by a power factor improving transformer (a loosely coupled transformer VFT), interrupting a rectification current by a rectifier diode, and thereby increasing a conduction angle of an alternating input current. Thus, for example, the power supply circuit having a power factor improving circuit does not need to employ a configuration in which a choke coil is inserted in a commercial alternating-current power supply line.
    Type: Grant
    Filed: November 28, 2003
    Date of Patent: January 2, 2007
    Assignee: Sony Corporation
    Inventor: Masayuki Yasumura
  • Publication number: 20060285367
    Abstract: The invention aims at putting a single ended resonance type converter capable of obtaining a ZVS operation over an overall corresponding load region to practical use. A switching power supply circuit includes a primary side switching converter of a class-E resonance type, and a choke coil of a primary side series resonance circuit of the class-E resonance type converter is used as a primary winding of an insulating converter transformer. With this structure, a choke coil winding to be inserted into an input line of a DC input voltage is arranged between a positive-polarity end portion of a smoothing capacitor, and a node between the primary winding and a primary side series resonance capacitor. Thus, a resonance pulse voltage generated in the choke coil winding is superimposed on an AC voltage in the primary winding. Also, a primary series resonance current is caused to separately flow through the choke coil winding.
    Type: Application
    Filed: June 8, 2006
    Publication date: December 21, 2006
    Applicant: Sony Corporation
    Inventor: Masayuki Yasumura
  • Patent number: 7145785
    Abstract: A power supply circuit is disclosed which performs constant voltage control by switching frequency control and is ready for a wide range while the necessary control range of the switching frequency control is reduced. The circuit includes a primary side series resonance circuit forming a current resonance type converter, and a secondary side series resonance circuit formed from secondary windings and secondary side series resonance capacitors while a coupling type resonance circuit by electromagnetic coupling of an insulating converter transformer is formed. To obtain a single-humped characteristic from the coupling type resonance circuit, a gap of approximately 1.6 mm is formed in the core of the insulating converter transformer so as to achieve a coupling coefficient of 0.65 or less. A secondary side DC output voltage is produced from outputs of the secondary windings so as to cope with a heavy load condition.
    Type: Grant
    Filed: September 1, 2005
    Date of Patent: December 5, 2006
    Assignee: Sony Corporation
    Inventor: Masayuki Yasumura
  • Publication number: 20060239039
    Abstract: A switching power supply circuit having a power factor improving function that makes it possible to improve power conversion efficiency and reduce size and weight of the circuit. A complex resonant converter is formed by at least combining a current resonant converter of a half-bridge coupling system on a primary side with a partial resonant voltage circuit. Power factor improvement is made by performing voltage feedback of a switching output of the complex resonant converter to a rectification current path by a power factor improving transformer (a loosely coupled transformer VFT), interrupting a rectification current by a rectifier diode, and thereby increasing a conduction angle of an alternating input current. Thus, for example, the power supply circuit having a power factor improving circuit does not need to employ a configuration in which a choke coil is inserted in a commercial alternating-current power supply line.
    Type: Application
    Filed: November 28, 2003
    Publication date: October 26, 2006
    Applicant: SONY CORPORATION
    Inventor: Masayuki Yasumura
  • Publication number: 20060227576
    Abstract: The present invention provides a voltage resonant converter that achieves ZVS over the entire allowable load range. A switching power supply circuit includes a class-E resonant converter as its primary-side switching converter that is supplied with a DC input voltage arising from the rectification and smoothing of a commercial AC voltage by a rectifier circuit (including a smoothing capacitor Ci). A choke coil of a primary-side series resonant circuit in the class-E switching converter is used as a primary winding N1 in an isolation converter transformer PIT. The total coupling coefficient between the primary side and secondary side is set to about 0.65 by the coupling coefficient of the isolation converter transformer PIT itself and equivalent parallel connection between a choke coil L10 and the primary winding N1. The resonant frequency fo1 of a primary-side parallel resonant circuit and the resonant frequency fo2 of the primary-side series resonant circuit are set to almost the same value of about 60 kHz.
    Type: Application
    Filed: April 5, 2006
    Publication date: October 12, 2006
    Applicant: Sony Corporation
    Inventor: Masayuki Yasumura
  • Publication number: 20060209576
    Abstract: A wide-range compatible voltage resonant converter provides high efficiency and allows use of low-breakdown-voltage products for a circuit. The voltage resonant converter is provided with a secondary-side parallel resonant circuit and a secondary-side series resonant circuit, and a loose coupling state is established in which the coupling coefficient of an isolation converter transformer is about 0.7 or less. Thus, a constant-voltage control characteristic is obtained as a sharp unimodal characteristic, which narrows the switching frequency control region required for stabilization of an output voltage. In addition, a primary-side parallel resonant frequency, a secondary-side parallel resonant frequency and a secondary-side series resonant frequency are set so that a favorable power conversion efficiency is obtained. Moreover, an active clamp circuit is provided to suppress the peak level of a resonant voltage pulse to thereby allow use of low-breakdown-voltage products for a switching element and so on.
    Type: Application
    Filed: March 6, 2006
    Publication date: September 21, 2006
    Applicant: Sony Corporation
    Inventor: Masayuki Yasumura
  • Patent number: 7110268
    Abstract: The present invention provides a power supply circuit performing constant voltage control by switching frequency control and achieving minimization of a necessary control range of the switching frequency control and implementation of a configuration ready for a wide range. A switching power supply circuit includes a switching circuit, a switching driving unit, an insulating converter transformer, a primary side series resonance circuit, a secondary side series resonance circuit, a secondary side DC output voltage production unit, a constant voltage control circuit, and a composite coupling coefficient setting mechanism.
    Type: Grant
    Filed: May 31, 2005
    Date of Patent: September 19, 2006
    Assignee: Sony Corporation
    Inventor: Masayuki Yasumura
  • Publication number: 20060192774
    Abstract: A switching power supply circuit ready for a wide range and including a power factor improving function is disclosed which can achieve reduction in cost, reduction in size and weight of the circuit and reduction of the power loss by reducing the number of converter sections with respect to the number of stages in a starting order of secondary side DC output voltages. A plurality of switching converters (101), (102) are of the composite resonance type wherein a partial resonance voltage circuit is combined with a switching converter of the current resonance type according to a half-bridge connection system. Changeover control is performed such that a rectification circuit serves as a voltage doubler rectification circuit at an AC voltage equal to or lower than 150 V, but serves as a full-wave rectification circuit at another AC voltage equal to or higher than 150 V.
    Type: Application
    Filed: December 19, 2003
    Publication date: August 31, 2006
    Applicant: Sony Corporation
    Inventor: Masayuki Yasumura
  • Publication number: 20060187687
    Abstract: An abnormal operation in which a current flows through a switching device before the end of an off period of the switching device at medium load is eliminated by setting the coupling coefficient of an isolated converter transformer to about 0.7 or lower. A primary side parallel resonance frequency and a secondary side series resonance frequency are set so as to obtain favorable power conversion efficiency characteristics.
    Type: Application
    Filed: January 24, 2006
    Publication date: August 24, 2006
    Applicant: Sony Corporation
    Inventor: Masayuki Yasumura
  • Patent number: 7095629
    Abstract: A switching power supply circuit in which, in order to both provide high power conversion efficiency of a complex resonant converter having a synchronous rectifier circuit and reduce a circuit scale and cost by simplifying the circuit, a synchronous rectifier circuit of a winding voltage detection system is provided on a secondary side of the complex resonant converter, a coupling coefficient is decreased to about 0.8 by setting a gap length in an isolated converter transformer to about 1.5 mm, and numbers of turns of a primary winding and secondary windings are set such that a level of a voltage induced per turn (T) of the secondary windings is 2 V/T. Thus, since magnetic flux density at a core of the isolated converter transformer is decreased to a certain value or lower, a secondary side rectified current can be in a continuous mode even under a condition of heavy load.
    Type: Grant
    Filed: August 5, 2004
    Date of Patent: August 22, 2006
    Assignee: Sony Corporation
    Inventor: Masayuki Yasumura
  • Publication number: 20060176714
    Abstract: A voltage resonant converter is provided with a secondary side parallel resonant circuit, and an isolated converter transformer PIT is set in a state of loose coupling at a coupling coefficient k=about 0.7 or lower. Thus a steep unimodal characteristic is obtained as a constant-voltage control characteristic to reduce a control range of switching frequency which range is necessary for stabilization. A primary side parallel resonance frequency fo1 and a secondary side parallel resonance frequency fo2 are set so as to obtain favorable power conversion efficiency characteristics.
    Type: Application
    Filed: January 26, 2006
    Publication date: August 10, 2006
    Applicant: Sony Corporation
    Inventor: Masayuki Yasumura
  • Publication number: 20060164870
    Abstract: A wide-range compatible switching power supply circuit employs switching frequency varying control and allows enhancement of its AC to DC power conversion efficiency when a large AC input voltage is used. A coupled resonant circuit employing electromagnetic coupling by an isolation converter transformer is formed by providing a series resonant circuit both on the primary side and on the secondary side of the transformer. In order to achieve a unimodal output characteristic in the coupled resonant circuit, the length of a gap formed in a core of the isolation converter transformer is set to about 2.0 mm, and a coupling coefficient is set to about 0.8 or less. Thus, the switching frequency variable control range can be narrowed, which allows a wide-range compatible configuration.
    Type: Application
    Filed: January 3, 2006
    Publication date: July 27, 2006
    Applicant: Sony Corporation
    Inventor: Masayuki Yasumura
  • Publication number: 20060126364
    Abstract: A switching power supply circuit which can achieve enhancement of the power conversion efficiency is disclosed. In a composite resonance converter wherein a current resonance type converter constructed on the primary side and a primary side partial voltage resonance circuit are combined, a primary side DC input rectification circuit is formed from a full-wave rectification circuit. Further, a gap G of the core of an insulating converter transformer (PIT) is set to 2.0 mm to set the coupling coefficient of the primary winding (N1) and the secondary winding (N2) to approximately 0.81 of a loose coupling state. Further, the numbers of turns of the primary winding (N1) and the secondary winding (N2) are selected so that the induced voltage per one turn of the secondary winding (N2) is 2 V or less.
    Type: Application
    Filed: August 8, 2003
    Publication date: June 15, 2006
    Inventor: Masayuki Yasumura