Hang-Seok
Hang-Seok Choi, Gunpo KR
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20100014331 | Power Converter, Switching Control Device Thereof, And Driving Method Thereof - A power converter according to the present invention includes a power supply unit, an output unit, and a switching controller. The power supply unit includes a primary coil of a transformer that receives an input voltage, a gate electrode, and a switch having a first electrode and a second electrode that is connected to the primary coil. The output unit includes a secondary coil of the transformer, and outputs an output voltage that is converted from the input voltage by the transformer. The switching controller includes a feedback terminal that receives a feedback voltage corresponding to the output voltage, generates a burst voltage by compensating the feedback voltage according to a maximum current value that can flow between the second electrode and the first electrode of the switch, determines whether to perform a burst mode operation according to the burst voltage, and transmits a gate signal according to performance of the burst mode operation to the gate electrode of the switch. | 01-21-2010 |
20100039834 | Power Converter, And Switching Controller And Driving Method Thereof - In a power converter, a primary coil of a transformer receives an input voltage, and a first terminal of a switch is coupled to the primary coil. An output unit includes a secondary coil of the transformer, and outputs an output voltage to which the input voltage is converted by the transformer. A switching controller receives a feedback voltage corresponding to the output voltage and a sensing voltage corresponding to a current flowing between the first terminal and a second terminal of the switch. The switching controller determines whether to perform an operation of a burst mode based on the feedback voltage. The switching controller generates a control signal by comparing the sensing voltage with a comparison voltage during a first period of the burst mode, generates the control signal by comparing the sensing voltage with a voltage corresponding to the feedback voltage during a second period of the burst mode, and transmits the control signal to a control terminal of the switch. | 02-18-2010 |
Hang-Seok Choi, Gyeonggi-Do KR
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20090251929 | Convertor and Driving Method Thereof - A converter and a driving method thereof are provided. The converter includes first and second switches, and generates a square wave signal according to operations of the first and second switches. The converter includes a first capacitor and a primary coil, and resonates a driving voltage by using a driving voltage with the first capacitor and the primary coil so as to generate a driving current. The converter includes a secondary coil that forms the primary coil and the transformer, and generates output power by rectifying a current and a voltage generated in the secondary coil. In addition, the converter detects the phase of the driving current, and increases switching frequencies of the first and second switches if a phase difference of the phase of the driving current and that of the driving voltage is smaller than a predetermined value. | 10-08-2009 |
Hang-Seok Choi, Kunpo KR
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20080259659 | Overload and short protected soft-start converter - A converter and a driving method thereof are provided. The converter can determine the output short state of the converter after the soft start is finished by using a detection signal that corresponds to an input signal while a switched is turned on and that corresponds to an output signal while the switch is turned off, so as to convert the input signal into the output signal according to a switching operation of the switch. The converter can determine the overload state of the converter by using a feedback voltage corresponding to the output signal, and terminate the switching operation when the converter is in an output short state or overload state. | 10-23-2008 |
20090091955 | Quasi resonant switching mode power supply - A switching mode power supply (SMPS) and a driving method thereof are provided. The SMPS includes a power supply block that includes a first switch coupled to a first coil of a primary side of a transformer for converting an input voltage, wherein the power supply block supplies power to a second coil and a third coil of a secondary side of the transformer according to operation of the first switch; and a PWM signal generator determines a turn-on time of the first switch according to the input voltage, and the turn-on time is determined regardless of a power magnitude of an output terminal connected to the second coil. Accordingly, screen noise due to a ripple can be eliminated and stress on the switch breakdown due to excessive power input can be reduced to enable an SMPS with stable driving. | 04-09-2009 |
Hang-Seok Choi, Daejeon KR
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20120066963 | DEVICE FOR PREPARING BIO-OIL, SYSTEM FOR PREPARING BIO-OIL AND METHOD FOR PREPARING BIO-OIL USING THE SAME - A device for preparing bio-oil, a system for preparing bio-oil and a method for preparing bio-oil using the same are provided. Biomass is supplied to an inclined portion of a reactor, and high-temperature hot sand is supplied to an upper side of the biomass supplied to the inclined portion. Then, a heater heats the inclined portion. Thus, the fast pyrolysis performance of the biomass can be enhanced, thereby increasing the yield of bio-oil. Also, combustion gas produced from the heater is supplied to the interior of the reactor, so that the interior of the reactor can be simply formed under a nonoxidizing atmosphere. Accordingly, the device for preparing bio-oil can be manufactured into a very simple structure. | 03-22-2012 |
Hang-Seok Choi, Seoul KR
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20130324058 | Wireless Communication Device - A wireless communication device includes an antenna, a transceiver, a filter circuit and an attenuation circuit. The transceiver includes a transmission electrode and a receive electrode, and communicates with an external device through the antenna. The filter circuit is coupled between the transmission electrode and the antenna, and includes a harmonic trap circuit that eliminates a harmonic element of a carrier frequency of an outgoing signal provided from the transceiver through the transmission electrode. The attenuation circuit is coupled between the receive electrode and the antenna, and provides an incoming signal received through the antenna to the receive electrode after reducing a voltage of the incoming signal. | 12-05-2013 |