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).
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Publication number: 20060114697Abstract: In 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: ApplicationFiled: August 5, 2004Publication date: June 1, 2006Inventor: Masayuki Yasumura
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Patent number: 7054167Abstract: A switching power supply circuit achieves improvement of the power conversion efficiency while a high power factor is maintained, in which the power factor of a current resonance converter is improved by feeding back a switching output to a rectification current path to selectively interrupt the rectification current, thereby to expand the conduction angle of ac input current. This allows elimination of a power choke coil to achieve improvement of the power conversion efficiency. Further, the magnetic flux density of an insulating converter transformer is set lower than a predetermined level, so that secondary side rectification current normally maintains a continuous mode irrespective of a variation of the load or the input voltage. This decreases the power loss that appears when the secondary side rectification current is placed into a discontinuous mode and thereby achieves further improvement of the power conversion efficiency.Type: GrantFiled: November 5, 2004Date of Patent: May 30, 2006Assignee: Sony CorporationInventor: Masayuki Yasumura
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Publication number: 20060077600Abstract: A secondary side series resonant circuit formed by at least one secondary winding and a secondary side series resonant capacitor is provided together with a secondary side series resonant circuit forming a current resonant converter, whereby a coupling type resonant circuit is formed by magnetic coupling of an isolated converter transformer. For this coupling type resonant circuit to obtain a unimodal characteristic, a gap G formed in a core of the isolated converter transformer PIT is set to about 2.4 mm, and a coupling coefficient k is set to k=0.65 or lower. Thereby, the variable control range of switching frequency can be reduced, and a wide range-ready configuration can be realized. Also, since the variable control range of the switching frequency can be thus reduced, cross regulation of secondary side direct-current output voltage ?Eo can be improved.Type: ApplicationFiled: September 13, 2005Publication date: April 13, 2006Applicant: Sony CorporationInventor: Masayuki Yasumura
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Publication number: 20060062025Abstract: 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: ApplicationFiled: September 1, 2005Publication date: March 23, 2006Applicant: Sony CorporationInventor: Masayuki Yasumura
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Publication number: 20060037461Abstract: 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: ApplicationFiled: August 13, 2004Publication date: February 23, 2006Inventor: Masayuki Yasumura
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Publication number: 20050281059Abstract: 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: ApplicationFiled: June 2, 2005Publication date: December 22, 2005Applicant: Sony CorporationInventor: Masayuki Yasumura
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Publication number: 20050270805Abstract: 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: ApplicationFiled: May 31, 2005Publication date: December 8, 2005Applicant: Sony CorporationInventor: Masayuki Yasumura
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Patent number: 6956749Abstract: A switching power supply circuit includes a converter transformer in which an output obtained by switching a direct current voltage of a converter through resonance is transmitted from the primary side to the secondary side. The switching power supply circuit further includes, on the secondary side of the converter transformer, a secondary step-up winding wound on a portion of a core together with a primary winding, and a low voltage secondary winding wound on another portion of the core. On the secondary side of the converter transformer, an alternating voltage obtained from the step-up winding is utilized to produce a direct current high voltage, and an alternating voltage obtained from the low voltage secondary winding is utilized to produce a direct current low voltage. Consequently, two different direct current outputs including the direct current high voltage and the direct current low voltage are obtained from the converter transformer.Type: GrantFiled: March 5, 2002Date of Patent: October 18, 2005Assignee: Sony CorporationInventor: Masayuki Yasumura
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Publication number: 20050168087Abstract: A switching power supply circuit including a configuration for power factor correction is disclosed which minimizes ripples and achieves a high power conversion efficiency. For power factor correction of a composite resonance converter including a partial resonance voltage circuit combined with a current resonance converter according to a half-bridge connection, a power factor correction circuit is configured such that primary side series resonance current obtained by a primary side series resonance circuit is regenerated and fed back as electric power to a smoothing capacitor. An insulating converter transformer of the composite resonance converter is formed such that the magnetic flux density therein is set so as to allow a secondary side rectification current to exhibit a continuous mode irrespective of any variation of the secondary side dc output voltage.Type: ApplicationFiled: December 21, 2004Publication date: August 4, 2005Applicant: Sony CorporationInventor: Masayuki Yasumura
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Publication number: 20050099826Abstract: A switching power supply circuit achieves improvement of the power conversion efficiency while a high power factor is maintained, in which the power factor of a current resonance converter is improved by feeding back a switching output to a rectification current path to selectively interrupt the rectification current, thereby to expand the conduction angle of ac input current. This allows elimination of a power choke coil to achieve improvement of the power conversion efficiency. Further, the magnetic flux density of an insulating converter transformer is set lower than a predetermined level, so that secondary side rectification current normally maintains a continuous mode irrespective of a variation of the load or the input voltage. This decreases the power loss that appears when the secondary side rectification current is placed into a discontinuous mode and thereby achieves further improvement of the power conversion efficiency.Type: ApplicationFiled: November 5, 2004Publication date: May 12, 2005Inventor: Masayuki Yasumura
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Publication number: 20050068792Abstract: A switching power supply circuit is disclosed which can achieve a high power conversion efficiency and besides achieve reduction of the circuit scale and the cost by simplification in circuit configuration. The switching power supply circuit includes a synchronous rectification circuit of the winding voltage detection system on the secondary side of a resonance converter. The coupling coefficient of an insulating converter transformer or the induced voltage level per one turn of the secondary winding is set so that the magnetic flux density of the insulating converter transformer may be lower than a fixed level thereby to maintain the secondary side rectification current in a continuous mode even in a heavy load condition.Type: ApplicationFiled: September 28, 2004Publication date: March 31, 2005Inventor: Masayuki Yasumura
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Patent number: 6839245Abstract: A switching power supply circuit ready for worldwide use is disclosed which suppresses a variation of a pulse voltage to be fed back when the alternating-current input varies. The switching power supply circuit includes a composite resonance type converter of a switching frequency control scheme wherein a voltage resonance pulse voltage generated in a primary side voltage resonance converter is fed back to a rectification diode through a high speed diode and an inductance or a transformer. An active clamp circuit is provided on the primary side to clamp the voltage resonance pulse voltage.Type: GrantFiled: November 15, 2002Date of Patent: January 4, 2005Assignee: Sony CorporationInventor: Masayuki Yasumura
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Patent number: 6831846Abstract: A complex resonance type switching converter provided with a self-excited voltage resonance type converter has a conduction controlling device Q2 connected in series with a control winding Nc of a drive transformer CDT in which a detecting winding NA, a driving winding NB of a self-oscillation driving circuit, and the control winding Nc are wound on an identical core. An amount of current conducted in the conduction controlling device Q2 is varied, whereby a level of a base current flowing from the self-oscillation driving circuit to a base of a switching device Q1 is changed and switching frequency of the switching device Q1 is variably controlled. Thereby a conduction angle and the switching frequency of the switching device are changed simultaneously, and consequently constant-voltage control is effected on a direct-current output on the secondary side of the converter. Use of such a drive transformer CDT makes it possible to prevent variations of the self-oscillation driving circuit and reduce size.Type: GrantFiled: May 14, 2004Date of Patent: December 14, 2004Assignee: Sony CorporationInventor: Masayuki Yasumura
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Publication number: 20040196671Abstract: A complex resonance type switching converter provided with a self-excited voltage resonance type converter has a conduction controlling device Q2 connected in series with a control winding Nc of a drive transformer CDT in which a detecting winding NA, a driving winding NB of a self-oscillation driving circuit, and the control winding Nc are wound on an identical core. An amount of current conducted in the conduction controlling device Q2 is varied, whereby a level of a base current flowing from the self-oscillation driving circuit to a base of a switching device Q1 is changed and switching frequency of the switching device Q1 is variably controlled. Thereby a conduction angle and the switching frequency of the switching device are changed simultaneously, and consequently constant-voltage control is effected on a direct-current output on the secondary side of the converter. Use of such a drive transformer CDT makes it possible to prevent variations of the self-oscillation driving circuit and reduce size.Type: ApplicationFiled: May 14, 2004Publication date: October 7, 2004Inventor: Masayuki Yasumura
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Publication number: 20040141340Abstract: A switching power supply circuit includes a converter transformer in which an output obtained by switching a direct current voltage of a converter through resonance is transmitted from the primary side to the secondary side. The switching power supply circuit further includes, on the secondary side of the converter transformer, a secondary step-up winding wound on a portion of a core together with a primary winding, and a low voltage secondary winding wound on another portion of the core. On the secondary side of the converter transformer, an alternating voltage obtained from the step-up winding is utilized to produce a direct current high voltage, and an alternating voltage obtained from the low voltage secondary winding is utilized to produce a direct current low voltage.Type: ApplicationFiled: February 27, 2004Publication date: July 22, 2004Inventor: Masayuki Yasumura
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Patent number: 6747883Abstract: In a complex resonance type switching power supply circuit including: a series resonant circuit formed by a leakage inductance component having a primary-side winding of an isolation converter transformer driven by switching devices formed by half-bridge coupling and a primary-side series resonant capacitor connected in series with the primary-side winding; and a partial voltage resonance circuit connected in parallel with one of the switching devices mentioned above, for effecting partial voltage resonance in time with the turning off of the switching devices, an auxiliary switching device of a series circuit is provided connected in parallel with the primary-side series resonant capacitor, formed by the auxiliary switching device and a capacitor, and is operated only during a period when the switching device connected in parallel with a primary-side partial resonance capacitor is on.Type: GrantFiled: January 30, 2003Date of Patent: June 8, 2004Assignee: Sony CorporationInventor: Masayuki Yasumura
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Patent number: 6731521Abstract: A circuit that includes a combination of a current resonance type converter of a switching frequency controlling system with a partial-voltage resonance circuit is configured such that, in order to improve the power factor where the load power is 150 W or more and the circuit employs an input double-voltage rectification system, a series resonance capacitor or inductor is connected in series to a tertiary winding wound on the primary side of an isolation converter transformer, so that the voltage is fed back to a rectification circuit composed of a high-speed recovery type diode.Type: GrantFiled: December 6, 2002Date of Patent: May 4, 2004Assignee: Sony CorporationInventor: Masayuki Yasumura
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Patent number: 6687137Abstract: A switching power supply circuit includes an insulating converter transformer where the insulating converter transformer has a gap formed therein so that a coupling which is efficient for a loose coupling is obtained; switching circuit, a primary side parallel resonance circuit formed from a leakage inductance component from the primary winding of the insulating converter transformer and a capacitance of a parallel resonance capacitor and a secondary side series resonance circuit including a secondary side series resonance capacitor and a secondary winding of the insulating converter transformer; a dc output voltage production means for performing a voltage multiplying full-wave rectification operation to produce a secondary side dc output voltage substantially equal to twice the input voltage level; and a constant voltage control means for varying a switching frequency of the switching element in order to perform constant voltage control of the secondary side output voltage.Type: GrantFiled: June 3, 2002Date of Patent: February 3, 2004Assignee: Sony CorporationInventor: Masayuki Yasumura
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Publication number: 20030198062Abstract: The present invention relates to a circuit which includes a combination of a current resonance type converter of a switching frequency controlling system with a partial voltage resonance circuit is configured such that, in order to improve the power factor where the load power is 150 W or more and the circuit employs an input double voltage rectification system, a series resonance capacitor or inductor is connected in series to a tertiary winding wound on the primary side of an isolation converter transformer so that the voltage is fed back to a rectification circuit composed of a high speed recovery type diode.Type: ApplicationFiled: December 6, 2002Publication date: October 23, 2003Inventor: Masayuki Yasumura
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Publication number: 20030155901Abstract: In a complex resonance type switching power supply circuit including: a series resonant circuit formed by a leakage inductance component having a primary-side winding of an isolation converter transformer driven by switching devices formed by half-bridge coupling and a primary-side series resonant capacitor connected in series with the primary-side winding; and a partial voltage resonance circuit connected in parallel with one of the switching devices mentioned above, for effecting partial voltage resonance in timing of turning off of the switching devices, an auxiliary switching device of a series circuit connected in parallel with the primary-side series resonant capacitor and formed by the auxiliary switching device and a capacitor is operated only during a period when the switching device connected in parallel with a primary-side partial resonance capacitor is on, and during this period, the capacitor of the series circuit is connected in parallel with the primary-side series resonant capacitor.Type: ApplicationFiled: January 30, 2003Publication date: August 21, 2003Inventor: Masayuki Yasumura