Patents by Inventor Yungtaek Jang

Yungtaek Jang 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).

  • Patent number: 10476433
    Abstract: A microwave generator includes a power supply, an output circuit, a feedback oscillator, a pulse controller, a signal combination circuit and a semiconductor amplifier. The power supply converts input voltage and input current into output voltage and output current. The output circuit generates a microwave signal to an output terminal of the microwave generator and a feedback signal according to the microwave signal. The feedback oscillator generates an oscillation signal according to the feedback signal. According to a reference signal, the pulse controller generates a pulse signal. According to the oscillation signal and pulse signal, the signal combination circuit generates a control signal. The semiconductor amplifier generates and adjusts an amplified signal according to the control signal. The output circuit generates the microwave signal according to the amplified signal. The output current is adjusted according to the amplified signal.
    Type: Grant
    Filed: June 23, 2017
    Date of Patent: November 12, 2019
    Assignee: DELTA ELECTRONICS, INC.
    Inventors: Yungtaek Jang, Yin-Yuan Chen, Sheng-Hua Li
  • Publication number: 20180013385
    Abstract: A microwave generator includes a power supply, an output circuit, a feedback oscillator, a pulse controller, a signal combination circuit and a semiconductor amplifier. The power supply converts input voltage and input current into output voltage and output current. The output circuit generates a microwave signal to an output terminal of the microwave generator and a feedback signal according to the microwave signal. The feedback oscillator generates an oscillation signal according to the feedback signal. According to a reference signal, the pulse controller generates a pulse signal. According to the oscillation signal and pulse signal, the signal combination circuit generates a control signal. The semiconductor amplifier generates and adjusts an amplified signal according to the control signal. The output circuit generates the microwave signal according to the amplified signal. The output current is adjusted according to the amplified signal.
    Type: Application
    Filed: June 23, 2017
    Publication date: January 11, 2018
    Inventors: Yungtaek Jang, Yin-Yuan Chen, Sheng-Hua Li
  • Patent number: 9705411
    Abstract: A bidirectional buck-boost converter includes at least one soft-switching cell to reduce switching losses by providing soft-switching of all semiconductor devices. A soft-switching cell comprises an active switch coupled in series with an inductor, a two-winding transformer, and a reset-voltage circuit. The soft-switching cells enable the buck and boost rectifiers to turn off with a controlled turn-off rate of their current to minimize their reverse-recovery losses, the power-controlling buck and boost switch to turn on with zero-voltage switching (ZVS), and the switch of the soft-switching cell to turn off with zero-current switching (ZCS).
    Type: Grant
    Filed: December 8, 2015
    Date of Patent: July 11, 2017
    Assignee: Delta Electronics, Inc.
    Inventors: Yungtaek Jang, Milan M. Jovanović
  • Publication number: 20170163163
    Abstract: A bidirectional buck-boost converter includes at least one soft-switching cell to reduce switching losses by providing soft-switching of all semiconductor devices. A soft-switching cell comprises an active switch coupled in series with an inductor, a two-winding transformer, and a reset-voltage circuit. The soft-switching cells enable the buck and boost rectifiers to turn off with a controlled turn-off rate of their current to minimize their reverse-recovery losses, the power-controlling buck and boost switch to turn on with zero-voltage switching (ZVS), and the switch of the soft-switching cell to turn off with zero-current switching (ZCS).
    Type: Application
    Filed: December 8, 2015
    Publication date: June 8, 2017
    Inventors: Yungtaek JANG, Milan M. Jovanovic
  • Patent number: 9490704
    Abstract: Control methods for resonant converters offer improved performance in resonant converters that operate with a wide input-voltage range or a wide output-voltage range (or both) by substantially reducing the switching-frequency range. Reduction in the switching frequency range is achieved by controlling the output voltage with a combination of variable-frequency control and time-delay control. Variable-frequency control may be used to control the primary switches of an isolated resonant converter, while delay-time control may be used to control secondary-side rectifier switches provided in place of diode rectifiers. The secondary-side control may be implemented by sensing the secondary current or the primary current (or both) and by delaying the turning-off of the corresponding secondary switch with respect to the zero crossings in the secondary current or the primary current.
    Type: Grant
    Filed: February 12, 2014
    Date of Patent: November 8, 2016
    Assignee: DELTA ELECTRONICS, INC.
    Inventors: Yungtaek Jang, Milan M. Jovanović
  • Publication number: 20150229225
    Abstract: Control methods for resonant converters offer improved performance in resonant converters that operate with a wide input-voltage range or a wide output-voltage range (or both) by substantially reducing the switching-frequency range. Reduction in the switching frequency range is achieved by controlling the output voltage with a combination of variable-frequency control and time-delay control. Variable-frequency control may be used to control the primary switches of an isolated resonant converter, while delay-time control may be used to control secondary-side rectifier switches provided in place of diode rectifiers. The secondary-side control may be implemented by sensing the secondary current or the primary current (or both) and by delaying the turning-off of the corresponding secondary switch with respect to the zero crossings in the secondary current or the primary current.
    Type: Application
    Filed: February 12, 2014
    Publication date: August 13, 2015
    Applicant: Delta Electronics, Inc.
    Inventors: Yungtaek Jang, Milan M. Jovanovic
  • Patent number: 9006930
    Abstract: A power supply is coupled to an input voltage source. The power supply includes a plurality of converters. Each converter has an input for receiving an input voltage and an output for providing an output voltage. The inputs are connected in series and the outputs are connected in parallel to provide an output voltage. The power supply further includes an output regulating controller coupled to one of the plurality of converters for regulating the output voltage. The power supply further includes one or more input regulating controllers correspondingly coupled to the remaining one or more converters of the plurality of converters for regulating one or more input voltages.
    Type: Grant
    Filed: July 8, 2010
    Date of Patent: April 14, 2015
    Assignee: Delta Electronics Inc.
    Inventors: Yungtaek Jang, Milan Jovanovic, Sheng-Hua Li, Chia-Cheng Yang
  • Patent number: 8891261
    Abstract: A low input-current-harmonic three-phase three-level boost rectifier includes an input stage for receiving a three-phase input voltage in relation to a neutral node and an output stage adapted to couple to at least one load. The rectifier further includes one or more switching converter stages, each having a plurality of serially-connected switches coupled to the neutral node, one of the serially-connected switches operating with a fixed duty cycle while the other of the serially-connected switches operating with a variable duty cycle, the fixed duty cycle being a substantially 50% duty cycle and the variable duty cycle being less than or equal to a substantially 50% duty cycle. The serially-connected switches are coupled to clamping diodes and clamping capacitors.
    Type: Grant
    Filed: April 11, 2013
    Date of Patent: November 18, 2014
    Assignee: Delta Electronics, Inc.
    Inventors: Yungtaek Jang, Milan M. Jovanović
  • Patent number: 8704474
    Abstract: A digital signal processor (DSP) is operable to receive a single-phase back electromotive force signal (back-EMF) fed back from a motor and control an inverter for driving the motor based on the single-phase back-EMF signal. The DSP includes an electrical angle building module, a rotation speed control module, and a pulse width modulation control module. In addition, the DSP further includes a field-weakening compensation module. The field-weakening compensation module is operable to automatically regulate an electrical angle based on a rotation speed of the motor and a set of predetermined compensation parameters so that the DSP can be operable to achieve an adaptive control. Furthermore, a motor control system and method are disclosed herein.
    Type: Grant
    Filed: July 8, 2011
    Date of Patent: April 22, 2014
    Assignee: Delta Electronics, Inc.
    Inventors: Cheng-Chung Li, Yungtaek Jang, Chang-Hsien Tu, Yen-Heng Lin
  • Patent number: 8687388
    Abstract: A low input-current harmonic three-phase boost rectifier includes an input stage for receiving a three-phase input voltage in relation to a neutral node and an output stage adapted to couple to at least one load. The rectifier further includes one or more switching converter stages, each having a plurality of switches coupled to the neutral node, the plurality of switches operating with a fixed duty cycle, the fixed duty cycle being a substantially 50% duty cycle. The rectifier further includes one or more controllers adapted to vary the switching frequency of the plurality of switches based on at least one of a condition of the at least one load or the input voltage and includes one or more decoupling stages, each including one or more inductive elements adapted to inductively decouple the output stage from at least one of the one or more switching converter stages.
    Type: Grant
    Filed: January 31, 2012
    Date of Patent: April 1, 2014
    Assignee: Delta Electronics, Inc.
    Inventors: Yungtaek Jang, Milan Jovanovic
  • Publication number: 20130235626
    Abstract: A low input-current-harmonic three-phase three-level boost rectifier includes an input stage for receiving a three-phase input voltage in relation to a neutral node and an output stage adapted to couple to at least one load. The rectifier further includes one or more switching converter stages, each having a plurality of serially-connected switches coupled to the neutral node, one of the serially-connected switches operating with a fixed duty cycle while the other of the serially-connected switches operating with a variable duty cycle, the fixed duty cycle being a substantially 50% duty cycle and the variable duty cycle being less than or equal to a substantially 50% duty cycle. The serially-connected switches are coupled to clamping diodes and clamping capacitors.
    Type: Application
    Filed: April 11, 2013
    Publication date: September 12, 2013
    Applicant: Delta Electronics, Inc.
    Inventors: Yungtaek Jang, Milan M. Jovanovic
  • Publication number: 20130194838
    Abstract: A low input-current harmonic three-phase boost rectifier includes an input stage for receiving a three-phase input voltage in relation to a neutral node and an output stage adapted to couple to at least one load. The rectifier further includes one or more switching converter stages, each having a plurality of switches coupled to the neutral node, the plurality of switches operating with a fixed duty cycle, the fixed duty cycle being a substantially 50% duty cycle. The rectifier further includes one or more controllers adapted to vary the switching frequency of the plurality of switches based on at least one of a condition of the at least one load or the input voltage and includes one or more decoupling stages, each including one or more inductive elements adapted to inductively decouple the output stage from at least one of the one or more switching converter stages.
    Type: Application
    Filed: January 31, 2012
    Publication date: August 1, 2013
    Applicant: DELTA ELECTRONICS INC.
    Inventors: Yungtaek Jang, Milan Jovanovic
  • Patent number: 8299773
    Abstract: A power supply comprises an input voltage detector that detects a drop in input voltage that corresponds to an input voltage loss. A power converter is coupled to the input voltage detector. The power converter, which may be a boost converter or a power factor correction converter, has a switching device that is actuated in accordance with a duty cycle. A duty cycle adjuster is responsive to detection of the drop in the input voltage to adjust the duty cycle of the switching device in order to limit an input current surge through the switching device below a desired level after the input voltage returns.
    Type: Grant
    Filed: July 10, 2009
    Date of Patent: October 30, 2012
    Assignee: Delta Electronics, Inc.
    Inventors: Yungtaek Jang, Milan M. Jovanovic, Yi-Hsin Leu, Ming-Tsung Hsieh, Wei-Hsin Wen, Chi-Hsing Huang
  • Publication number: 20120200246
    Abstract: A digital signal processor (DSP) is operable to receive a single-phase back electromotive force signal (back-EMF) fed back from a motor and control an inverter for driving the motor based on the single-phase back-EMF signal. The DSP includes an electrical angle building module, a rotation speed control module, and a pulse width modulation control module. In addition, the DSP further includes a field-weakening compensation module. The field-weakening compensation module is operable to automatically regulate an electrical angle based on a rotation speed of the motor and a set of predetermined compensation parameters so that the DSP can be operable to achieve an adaptive control. Furthermore, a motor control system and method are disclosed herein.
    Type: Application
    Filed: July 8, 2011
    Publication date: August 9, 2012
    Applicant: DELTA ELECTRONICS, INC.
    Inventors: Cheng-Chung LI, Yungtaek JANG, Chang-Hsien TU, Yen-Heng LIN
  • Patent number: 8233298
    Abstract: A PFC rectifier comprises a first converter having a first output capacitor and a second converter having a second output capacitor. The first and second capacitors are coupled to each other to increase the output voltage of the PFC rectifier. For example the first or second output capacitors can be serially coupled to each other. At least one or both of the first or second converters comprise buck or buck-boost converters, including inverting or non-inverter buck converters. The first and second converters can also form a bi-directional ac-ac inverter.
    Type: Grant
    Filed: June 5, 2009
    Date of Patent: July 31, 2012
    Assignee: Delta Electronics, Inc.
    Inventors: Yungtaek Jang, Milan M. Jovanović
  • Patent number: 8179698
    Abstract: A power converter system supplies power to one or more loads. The power converter system comprises at least one power converter operating at a desired efficiency; and a power storage system coupled to the at least one power converter for receiving power supplied from the at least one power converter and storing power therein when the at least one power converter operates at an efficiency that is below the desired efficiency.
    Type: Grant
    Filed: March 24, 2009
    Date of Patent: May 15, 2012
    Assignee: Delta Electronics, Inc.
    Inventors: Yungtaek Jang, Milan M. Jovanović, Bruce C. H. Cheng
  • Publication number: 20120007431
    Abstract: A power supply is coupled to an input voltage source. The power supply includes a plurality of converters. Each converter has an input for receiving an input voltage and an output for providing an output voltage. The inputs are connected in series and the outputs are connected in parallel to provide an output voltage. The power supply further includes an output regulating controller coupled to one of the plurality of converters for regulating the output voltage. The power supply further includes one or more input regulating controllers correspondingly coupled to the remaining one or more converters of the plurality of converters for regulating one or more input voltages.
    Type: Application
    Filed: July 8, 2010
    Publication date: January 12, 2012
    Applicant: DELTA ELECTRONICS INC.
    Inventors: Yungtaek Jang, Milan Jovanovic, Sheng-Hua Li, Chia-Cheng Yang
  • Publication number: 20110006748
    Abstract: A power supply comprises an input voltage detector that detects a drop in input voltage that corresponds to an input voltage loss. A power converter is coupled to the input voltage detector. The power converter, which may be a boost converter or a power factor correction converter, has a switching device that is actuated in accordance with a duty cycle. A duty cycle adjuster is responsive to detection of the drop in the input voltage to adjust the duty cycle of the switching device in order to limit an input current surge through the switching device below a desired level after the input voltage returns.
    Type: Application
    Filed: July 10, 2009
    Publication date: January 13, 2011
    Applicant: DELTA ELECTRONICS INC.
    Inventors: Yungtaek Jang, Milan M. Jovanovic, Yi-Hsin Leu, Ming-Tsung Hsieh, Wei-Hsin Wen, Chi-Hsing Huang
  • Publication number: 20090303762
    Abstract: A PFC rectifier comprises a first converter having a first output capacitor and a second converter having a second output capacitor. The he first and second capacitors are coupled to each other to increase the output voltage of the PFC rectifier. Fore example the first or second output capacitors can be serially coupled to each other. At least one or both of the first or second converters comprise buck or buck-boost converters, including inverting or non-inverter buck converters. The first and second converters can also form a bi-directional ac-ac inverter.
    Type: Application
    Filed: June 5, 2009
    Publication date: December 10, 2009
    Applicant: Delta Electronics, Inc.
    Inventors: Yungtaek Jang, Milan M. Jovanovic
  • Publication number: 20090244944
    Abstract: A power converter system supplies power to one or more loads. The power converter system comprises at least one power converter operating at a desired efficiency; and a power storage system coupled to the at least one power converter for receiving power supplied from the at least one power converter and storing power therein when the at least one power converter operates at an efficiency that is below the desired efficiency.
    Type: Application
    Filed: March 24, 2009
    Publication date: October 1, 2009
    Applicant: Delta Electronics, Inc.
    Inventors: Yungtaek Jang, Milan M. Jovanovic, Bruce C.H. Cheng