Patents by Inventor Chung-wook Roh

Chung-wook Roh 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: 20240021923
    Abstract: In an embodiment a power apparatus includes a fuel cell configured to supply power to an inverter of a vehicle, a supercapacitor configured to assist the fuel cell, a bidirectional converter configured to charge and discharge the fuel cell and the supercapacitor and a controller configured to drive the vehicle by controlling the supercapacitor to be charged and discharged depending on a current required by the inverter for driving the vehicle and to assist the fuel cell.
    Type: Application
    Filed: November 7, 2022
    Publication date: January 18, 2024
    Inventors: Yong Hwi Lee, Young Woo Noh, Chung Wook Roh, Hee Seong Jeong, Dong Woo Kwon, Gun Woo Park, Kang Hyun Woo
  • Patent number: 9844099
    Abstract: An induction heating apparatus in accordance with the present disclosure includes a coil; an inverter unit configured to have a switching device turned on and off to supply power to the coil; a first controller configured to generate a first threshold current based on information about a coil current flowing in the coil and an input voltage applied to the coil, and generate a clock signal by comparing the coil current with the first threshold current; and a switch driver configured to generate a switch driving signal to turn on or off the switching device of the inverter unit by dividing a frequency of the clock signal.
    Type: Grant
    Filed: October 8, 2014
    Date of Patent: December 12, 2017
    Assignee: SAMSUNG ELECTRONICS CO., LTD.
    Inventors: Chang Sun Yun, Ki Hyeon Park, Chung-Wook Roh, Sang Eon Kim
  • Publication number: 20150201467
    Abstract: An induction heating apparatus in accordance with the present disclosure includes a coil; an inverter unit configured to have a switching device turned on and off to supply power to the coil; a first controller configured to generate a first threshold current based on information about a coil current flowing in the coil and an input voltage applied to the coil, and generate a clock signal by comparing the coil current with the first threshold current; and a switch driver configured to generate a switch driving signal to turn on or off the switching device of the inverter unit by dividing a frequency of the clock signal.
    Type: Application
    Filed: October 8, 2014
    Publication date: July 16, 2015
    Applicant: Samsung Electronics Co., Ltd.
    Inventors: Chang Sun YUN, Ki Hyeon PARK, Chung-Wook ROH, Sang Eon KIM
  • Patent number: 8810213
    Abstract: A power control method for tracking a Maximum Power Point (MPP) in a photovoltaic system including a solar cell and a boost converter. The power control method includes finding the MPP by applying a continuous ON/OFF signal to the boost converter as a first control signal for controlling a duty ratio of the boost converter, and maintaining an operating point of the photovoltaic system at the MPP by applying a second control signal for controlling the duty ratio to the boost converter depending on a constant-voltage command. In tracking an MPP in a photovoltaic system, an MPPT algorithm may remain at the MPP, without self oscillation, improving fast dynamic characteristics upon a change in solar radiation.
    Type: Grant
    Filed: July 8, 2011
    Date of Patent: August 19, 2014
    Assignee: Samsung Electronics Co., Ltd
    Inventors: Yong-Woo Kim, Sang-Keun Ji, Sung-Soo Hong, Chung-Wook Roh, Sang-Kyoo Han
  • Patent number: 8508144
    Abstract: The power supply includes: an electromagnetic interference filter including a first filter which has a pair of electromagnetically coupled cores having at least two leg parts, first and second bobbins each having a tube-shaped body part having a penetration hole into which each of the leg parts is inserted and having a winding region defined as the circumference of the outer peripheral surface of the body part, and first and second coils respectively wound around the first and second bobbins to remove common mode electromagnetic interference included in power transmitted from a power line, the electromagnetic interference filter removing differential mode electromagnetic interference due to leakage inductance formed due to the leakage of magnetic flux flowing through the cores; a power factor corrector correcting a power factor of the power where the electromagnetic interference is removed; and a power converter switching the power-factor-corrected power into a driving power having a predetermined voltage lev
    Type: Grant
    Filed: April 26, 2011
    Date of Patent: August 13, 2013
    Assignee: Samsung Electro-Mechanics Co., Ltd.
    Inventors: Sang Kyoo Han, Sung Soo Hong, Mi Ran Baek, Chung Wook Roh, Hee Seung Kim, Jae Sun Won, Ku Yong Kim, Jae Cheol Ju, Don Sik Kim, Dong Jin Lee
  • Patent number: 8446103
    Abstract: There is provided a lamp driver including: a power supplying part switching an input power, supplying a driving power to at least one lamp, and controlling brightness of the at least one lamp according to a dimming signal; a signal supplying part supplying a first comparison result signal obtained by comparing a current sensing signal sensing a current flowing through the at least one lamp with a reference signal having a current level set beforehand when the dimming signal is a logic high signal, and supplying a second comparison result signal having a voltage level set beforehand when the dimming signal is a logic low signal; and a controlling part controlling the switching of the power supplying part according to a signal being supplied by the signal supplying part.
    Type: Grant
    Filed: September 21, 2010
    Date of Patent: May 21, 2013
    Assignee: Samsung Electro-Mechanics Co., Ltd.
    Inventors: Sang Kyoo Han, Sung Soo Hong, Chung Wook Roh, Sang Gab Park, Young Seung Roh, Hyo Joong An, Heung Gyoon Choi, Han Hee Lee
  • Patent number: 8373354
    Abstract: There is provided a backlight unit driver capable of driving multi-channel lamps of a backlight unit, especially LED lamps, by supplying a driving power to the lamps using a single transformer and maintaining the current balance of the driving power supplied to each of the lamps.
    Type: Grant
    Filed: February 7, 2011
    Date of Patent: February 12, 2013
    Assignee: Samsung Electro-Mechanics, Co., Ltd.
    Inventors: Sang Kyoo Han, Sung Soo Hong, Chung Wook Roh, Sang Gab Park, Kyu Min Park, Young Seung Roh, Heung Gyoon Choi, Nam Jin Park
  • Patent number: 8305058
    Abstract: The present invention relates to power supplies, and more particularly, to a power supply having a maximum power point tracking function that can reduce manufacturing costs and circuit size by using a maximum power point tracking section with a simplified circuit in a solar photovoltaic power generator supplying power using sunlight instead of using a micro controller, the maximum power point tracking section that controls power switching according to a result of integration of a value obtained by dividing a power variation by a voltage variation to track a maximum power value.
    Type: Grant
    Filed: October 31, 2008
    Date of Patent: November 6, 2012
    Assignee: Samsung Electro-Mechanics Co., Ltd.
    Inventors: Jin Wook Kim, Sung Soo Hong, Sang Kyoo Han, Chung Wook Roh, Jong Sun Kim, Sang Hun Lee, Jae Sun Won, Dong Seong Oh, Jong Hae Kim
  • Patent number: 8274805
    Abstract: There is provided a high voltage power supply capable of reducing voltage stress of a voltage multiplying device. The high voltage power supply includes: a power converter switching on/off and converting an input direct current power into a direct current power having a preset voltage level; and a voltage multiplier including a first multiplying cell multiplying the voltage level of the direct current power from the power converter, wherein the first multiplying cell includes: first and second capacitors charging the direct current power from the power converter, respectively; a first diode providing a path for transferring the direct current power when the power converter is switched off; and a second diode providing a path for transferring the direct current power when the power converter is switched on.
    Type: Grant
    Filed: October 27, 2008
    Date of Patent: September 25, 2012
    Assignee: Samsung Electro-Mechanics Co., Ltd.
    Inventors: Jin Wook Kim, Sug Chin Sakong, Sung Soo Hong, Sang Kyoo Han, Chung Wook Roh, Jong Sun Kim, Dong Seong Oh, Jae Sun Won, Jong Hae Kim
  • Publication number: 20120176102
    Abstract: A power control method for tracking a Maximum Power Point (MPP) in a photovoltaic system including a solar cell and a boost converter. The power control method includes finding the MPP by applying a continuous ON/OFF signal to the boost converter as a first control signal for controlling a duty ratio of the boost converter, and maintaining an operating point of the photovoltaic system at the MPP by applying a second control signal for controlling the duty ratio to the boost converter depending on a constant-voltage command. In tracking an MPP in a photovoltaic system, an MPPT algorithm may remain at the MPP, without self oscillation, improving fast dynamic characteristics upon a change in solar radiation.
    Type: Application
    Filed: July 8, 2011
    Publication date: July 12, 2012
    Applicant: Samsung Electronics Co., Ltd.
    Inventors: Yong-Woo KIM, Sang-Keun Jl, Sung-Soo Hong, Chung-Wook Roh, Sang-Kyoo Han
  • Publication number: 20120153857
    Abstract: The power supply includes: an electromagnetic interference filter including a first filter which has a pair of electromagnetically coupled cores having at least two leg parts, first and second bobbins each having a tube-shaped body part having a penetration hole into which each of the leg parts is inserted and having a winding region defined as the circumference of the outer peripheral surface of the body part, and first and second coils respectively wound around the first and second bobbins to remove common mode electromagnetic interference included in power transmitted from a power line, the electromagnetic interference filter removing differential mode electromagnetic interference due to leakage inductance formed due to the leakage of magnetic flux flowing through the cores; a power factor corrector correcting a power factor of the power where the electromagnetic interference is removed; and a power converter switching the power-factor-corrected power into a driving power having a predetermined voltage lev
    Type: Application
    Filed: April 26, 2011
    Publication date: June 21, 2012
    Applicant: SAMSUNG ELECTRO-MECHANICS CO., LTD.
    Inventors: Sang Kyoo HAN, Sung Soo HONG, Mi Ran BAEK, Chung Wook ROH, Hee Seung KIM, Jae Sun WON, Ku Yong KIM, Jae Cheol JU, Don Sik KIM, Dong Jin LEE
  • Patent number: 8120278
    Abstract: The present invention provides an LED driving circuit including: an inverter unit for switching an input power source; a plurality of transformers including a plurality of primary windings connected to the inverter unit and connected to each other in series and a plurality of secondary windings each of which is coupled with each of the primary windings; a plurality of rectification units each of which is connected to each of the secondary windings; and a plurality of LEDs each of which is connected to each of the rectification units.
    Type: Grant
    Filed: May 28, 2009
    Date of Patent: February 21, 2012
    Assignee: Samsung Electro-Mechanics Co., Ltd.
    Inventors: Heung Gyoon Choi, Sung Soo Hong, Sang Kyoo Han, Chung Wook Roh, Sang Ho Cho, Sang Hyun Lee, Sung Ho Kim, Tae Hyung Kang, Jae Sun Won
  • Patent number: 8107262
    Abstract: There is provided a variable switching frequency type power supply that can achieve high efficiency by fixing a switching duty cycle to 50% and varying switching frequency. A variable switching frequency type power supply according to an aspect of the invention may include: a switching unit switching input power; a transformation unit converting a voltage level of the power switched by the switching unit into a predetermined voltage level; a rectification unit rectifying the power converted by the transformation unit; and a control unit fixing a switching duty cycle of the switching unit to a predetermined switching duty cycle, and varying switching frequency of the switching unit according to a voltage level of output power.
    Type: Grant
    Filed: December 10, 2008
    Date of Patent: January 31, 2012
    Assignee: Samsung Electro-Mechanics Co., Ltd.
    Inventors: Jae Sun Won, Sung Soo Hong, Chung Wook Roh, Sang Kyoo Han, Jong Sun Kim, Dong Seong Oh, Tae Won Heo, Dong Joong Kim, Don Sik Kim, Hak Ryong Kim
  • Publication number: 20110234111
    Abstract: There is provided a lamp driver including: a power supplying part switching an input power, supplying a driving power to at least one lamp, and controlling brightness of the at least one lamp according to a dimming signal; a signal supplying part supplying a first comparison result signal obtained by comparing a current sensing signal sensing a current flowing through the at least one lamp with a reference signal having a current level set beforehand when the dimming signal is a logic high signal, and supplying a second comparison result signal having a voltage level set beforehand when the dimming signal is a logic low signal; and a controlling part controlling the switching of the power supplying part according to a signal being supplied by the signal supplying part.
    Type: Application
    Filed: September 21, 2010
    Publication date: September 29, 2011
    Applicant: SAMSUNG ELECTRO-MECHANICS CO., LTD.
    Inventors: Sang Kyoo Han, Sung Soo Hong, Chung Wook Roh, Sang Gab Park, Young Seung Roh, Hyo Joong An, Heung Gyoon Choi, Han Hee Lee
  • Publication number: 20110222849
    Abstract: Disclosed herein is an optical transmission apparatus for visible light communication. The optical transmission apparatus includes a power conversion unit, a drive unit, an encoding unit, a control unit, and a detection unit. The power conversion unit provides Direct Current (DC) power to the lighting LED lamps. The drive unit is operated using a switching drive method and supplies operating current to the lighting LED lamps. The encoding unit is connected to an external network, receives and encodes data, and provides it to the drive unit. The control unit controls the operation of the power conversion unit, the drive unit, and the encoding unit. The detection unit measures the strength of a visible light signal sent by the lighting LED lamps.
    Type: Application
    Filed: January 11, 2011
    Publication date: September 15, 2011
    Applicant: KOOKMIN UNIVERSITY INDUSTRY-ACADEMIC COOPERATION FOUNDATION
    Inventors: Sang-Kyoo HAN, Sung-Soo Hong, Byung-Jun Jang, Chung-Wook Roh
  • Publication number: 20110204804
    Abstract: There is provided a backlight unit driver capable of driving multi-channel lamps of a backlight unit, especially LED lamps, by supplying a driving power to the lamps using a single transformer and maintaining the current balance of the driving power supplied to each of the lamps.
    Type: Application
    Filed: February 7, 2011
    Publication date: August 25, 2011
    Applicant: SAMSUNG ELECTRO-MECHANICS CO., LTD.
    Inventors: Sang Kyoo HAN, Sung Soo HONG, Chung Wook ROH, Sang Gab PARK, Kyu Min PARK, Young Seung ROH, Heung Gyoon CHOI, Nam Jin PARK
  • Patent number: 7940032
    Abstract: A power supply having a maximum power point tracking function that controls power switching so that a detected power value is within a reference range having a maximum power point in a predetermined current-voltage curve includes: a converter section switching input power and converting the switched input power into predetermined DC power; and a maximum power point tracking section detecting a power value determined according to a switching operation of the converter section among power values included in a predetermined power-voltage curve, and controlling the switching operation of the converter section so that the detected power value is located within a predetermined reference range having a maximum power value among the power values included in the power-voltage curve.
    Type: Grant
    Filed: October 31, 2008
    Date of Patent: May 10, 2011
    Assignee: Samsung Electro-Mechanics Co., Ltd.
    Inventors: Jin Wook Kim, Sung Soo Hong, Chung Wook Roh, Sang Kyoo Han, Jong Sun Kim, Jae Sun Won, Dong Seong Oh, Dea Min Jang, Jong Hae Kim
  • Patent number: 7915757
    Abstract: Disclosed is a multi-output DC/DC converter controlling power-conversion switching in synchronization with a frequency of one output voltage among multiple output voltages in an LLC resonant DC/DC converter. The multi-output DC/DC converter includes a power conversion circuit performing alternate switching on an input DC voltage to output multiple DC voltages including a first DC voltage and a second DC voltage each having a preset voltage level, and a control circuit controlling the alternate switching of the power conversion circuit in synchronization with a preset resonant frequency.
    Type: Grant
    Filed: October 1, 2008
    Date of Patent: March 29, 2011
    Assignee: Samsung Electro-Mechanics Co., Ltd.
    Inventors: Jong Hae Kim, Sug Chin Sakong, Sung Soo Hong, Chung Wook Roh, Sang Kyoo Han, Jong Sun Kim, Dong Seong Oh
  • Publication number: 20100237799
    Abstract: The present invention provides an LED driving circuit including: an inverter unit for switching an input power source; a plurality of transformers including a plurality of primary windings connected to the inverter unit and connected to each other in series and a plurality of secondary windings each of which is coupled with each of the primary windings; a plurality of rectification units each of which is connected to each of the secondary windings; and a plurality of LEDs each of which is connected to each of the rectification units.
    Type: Application
    Filed: May 28, 2009
    Publication date: September 23, 2010
    Applicant: Samsung Electro-Mechanics Co., Ltd.
    Inventors: Heung Gyoon CHOI, Sung Soo Hong, Sang Kyoo Han, Chung Wook Roh, Sang Ho Cho, Sang Hyun Lee, Sung Ho Kim, Tae Hyung Kang, Jae Sun Won
  • Patent number: 7663322
    Abstract: There is provided a backlight driving system for a liquid crystal display that can reduce size and weight of a product because a DC-DC converter is not used when commercial AC power is converted into lamp driving power. A backlight driving system for a liquid crystal display according to an aspect of the invention includes a power supply unit converting commercial alternating current (AC) power into direct current (DC) power having a voltage level set beforehand, an inverter unit converting the DC power from the power supply unit into AC power at a one-to-one conversion ratio set beforehand, a boosting unit boosting the AC power from the inverter unit into lamp lighting power set beforehand; and a lamp group receiving the lamp lighting power from the boosting unit to emit light.
    Type: Grant
    Filed: March 7, 2008
    Date of Patent: February 16, 2010
    Assignee: Samsung Electro-Mechanics Co., Ltd.
    Inventors: Jin Wook Kim, Dong Seong Oh, Jong Duck Kim, Sug Chin Sakong, Sung Soo Hong, Sang Kyoo Han, Chung Wook Roh, Dea Min Jang, Sung Ho Kim, Jin Woo Cho, Kwang Seung Cho