University of Seoul Industry Cooperation Foundation

Samsung Electro-mechanics Co., Ltd.

Korea Institute of Science and Technology

Solum Co., Ltd.

Joong Ho Choi

Yong Seong Roh

Jae Shin Lee

Chang Sik Yoo

Yu Jin Jang

Young Jin Moon

Jeong Mo Yang

Chang Seok Lee

Sang Hyun Cha

Kang Yoon Lee

Deuk Hee Park

Hong Jin Kim

Hwan Chul Cho

Yun Joong Lee

Jeong Pyo Park

Jong Woo Lee

Jung Chul Gong

Young Jun Park

Je Hyuk Ryu

Byung Joo Hong

Hyung Gu Park

Ji Hwan Kim

Joo Hyung Lee

Hye Jin Lee

Changsik Yoo

Je Hyeon Yu

Jung Sun Kwon

Dae Hoon Han

Seo Hyung Kim

Joon Youp Sung

Yeun Joong Lee

Dong Hyeon Seo

Seong Jin Oh

Jung Yeon Kim

Seung Ryung Ryu

Joo Young Lee

Ho Joon Jang

Hyeon Seon Yu

Yung Jin Moon

Soo Hyun Moon

A wireless power transmitter includes an amplifier configured to amplify a power; a transmitter configured to resonate the power amplified by the amplifier; and a reference signal provider configured to provide a reference signal to the amplifier and change a frequency of the reference signal.

Wireless power transmitter

A rectifier includes: a rectifying circuit configured to rectify alternating current (AC) power into direct current (DC) power through a switching operation; a driver configured to apply a switching signal to the rectifying circuit; and a signal modulator configured to select a parameter from among parameters of the switching signal based on a frequency of the switching signal, and adjust the selected parameter.

Rectifier and method of controlling the same

A gate driving circuit may include: a bias unit receiving an input signal having preset high and low signal levels, including a first N-MOSFET turned on in the case in which the input signal has the high level and a first P-MOSFET turned on in the case in which the input signal has the low level, and supplying bias powers by the turning-on of the first N-MOSFET and the first P-MOSFET; and an amplifying unit including a second N-MOSFET turned on by receiving the bias power supplied from the first N-MOSFET in the case in which the input signal has the high level and a second P-MOSFET turned on by receiving the bias power supplied from the first P-MOSFET turned on in the case in which the input signal has the low level and providing a gate signal depending on the turning-on of the second N-MOSFET and the second P-MOSFET.

Gate driving circuit including constant current sources, and switching apparatus and power supply apparatus having the same

Disclosed herein are a start-up circuit capable of reducing a leakage current to reduce power consumption, and a power device using the same. The start-up circuit includes: a bias unit connected between a first power source and a second power source and allowing a first current to flow from the first power source to the second power source according to a predetermined voltage; a first start unit connected to the bias unit and driving a second current to apply the predetermined voltage to the bias unit, and stopping driving the second current when a voltage received from the second power source reaches a first voltage; and a second start unit connected to the bias unit and driving a third current, the predetermined voltage being applied to the bias unit by the third current, and stopping driving the third current upon receiving a stop signal.

Start-up circuit and power device using the same

There are provided a phase shift circuit and a power factor correction circuit including the same. The phase shift circuit includes a switching circuit unit charging power in or discharging power from a capacitor through a plurality of switching devices and comparing a voltage of the capacitor with a predetermined reference voltage, and a clock generating unit generating a reference clock signal based on an output of the switching circuit unit, wherein the switching circuit unit turns the plurality of switching devices on or off, based on currents from inductors respectively included in a main circuit and a sub-circuit of a power factor correction circuit to determine a polarity of the voltage of the capacitor.

Phase shift circuit and power factor correction circuit including the same

A phase shift circuit may include a ramp generation unit charging or discharging a capacitor connected to a switch device to generate a ramp signal, a reference signal generation unit generating a predetermined reference signal from the ramp signal, and a comparison unit comparing the ramp signal with the reference signal to generate a clock signal, wherein at least one of the reference signal generation unit and the comparison unit changes a negative or positive value of offset components included in the reference signal or the ramp signal within every operating period of the switch device.

There is provided a power factor correction circuit including: a power conversion circuit unit controlling an inductor current according to a switching signal applied to a main switch to convert an external input voltage into an output voltage having a predetermined range; an imbalance detection circuit outputting an imbalance state signal when the external input voltage is in an unbalanced state by using the inductor current; and a soft start circuit unit performing soft starting by adjusting the switching signal when the imbalance state signal is output by the imbalance detection circuit unit.

Power factor correction circuit

There is provided an illumination driving apparatus for a light emitting diode, the apparatus including: a light emitting unit including M number of light emitting diodes (LEDs) connected in series and driven by an output voltage rectified in a rectifying unit; an LED switch unit including N number of LED switches connected in parallel with at least N number of the M LEDs, respectively, and connected in series; an LED switch control signal generating unit comparing the output voltage of the rectifying unit with each of the first to Nth preset reference voltages to generate N number of LED switch control signals controlling the LED switch unit; and an LED switch controlling unit transferring the N number of LED switch control signals to the LED switch unit.

Illumination driving apparatus for light emitting diode and method thereof

There are provided a power supply device switching power input to a primary side to supply the power to a predetermined load connected to a secondary side electrically insulated from the primary side and a control circuit thereof. The control circuit generates a predetermined PWM signal to apply the PWM signal to a dimming switch connected to an end of the load and controls a switching frequency of the primary side, based on a control voltage generated according to a feedback signal according to the power supplied to the load and the PWM signal, and the control voltage maintains a constant difference between a minimum voltage level and a maximum voltage level regardless of a duty of the PWM signal.

Power supply device and control circuit thereof

The present invention relates to an IC circuit. In an embodiment, an IC circuit includes: an RT terminal connected to an external; a current mirroring unit conducting a channel current between internal voltage power and the RT terminal and generating an internal reference current mirrored with the channel current; a negative feedback unit receiving the internal reference current, equalizing voltages of an RT terminal connection terminal and an internal reference current output terminal of the current mirroring unit to make the internal reference current constant, and providing the internal reference current inside the IC circuit; and an IC state indicating unit having a transistor, which operates complementarily with the current mirroring unit, connected between the RT terminal and a ground and providing the state of an IC or a system to the RT terminal by being linked with the complementary operation of the current mirroring unit.

IC circuit

There is provided a power factor correction circuit capable of correcting a power factor of a power converting module through increasing an input current by switching a main switching element of a power converting module on the basis of a first reference wave having a slope based on a first signal and an error voltage, in particular, by limiting a switching frequency on the basis of a first reference wave having a slope based on a second signal lower than a first signal and an error voltage when the switching frequency of the main switching element increases because an input voltage of the power converting module is low.

Power factor correction circuit for correcting power factor

A fixture-compatible, dimmable illumination driving apparatus including: a rectifying unit rectifying a phase-controlled waveform of an alternating current (AC) power; a comparing unit comparing an output waveform of the rectifying unit with a first voltage according to a preset reference clock; a reference voltage generating unit generating a reference voltage corresponding to the number of high signals higher than the first voltage among outputs of the comparing unit during one cycle of the output waveform; and a pulse width modulation (PWM) signal generating unit generating a PWM signal from the reference voltage and a feedback voltage.

Illumination driving apparatus

A relaxation oscillator includes a ramp wave generator configured to generate a ramp wave by complementary first capacitor module charged and discharged according to a first switching signal and second capacitor module charged and discharged according to a second switching signal, a negative feedback circuit unit configured to generate a compensation voltage for compensating an error between the ramp wave and a reference voltage through a feedback of the ramp wave, and a switching signal generator configured to generate the first switching signal and the second switching signal from the compensation voltage and the ramp wave, including a peak voltage storage unit configured to store a peak voltage of the ramp wave that is controlled to be equal to the reference voltage based on the compensation voltage and a peak voltage transfer unit configured to transfer the peak voltage of the ramp wave to the negative feedback unit.

Relaxation oscillator

A scent diffusion apparatus and method contains individual original scents for a plurality of scents to be diffused, constructs information on position information of the contained original scents and information on various scents to be diffused in a database, and mixes the original scents of the desired scent properly at a desired point in time based on the scent information, to thereby spray the desired scent. The scent diffusion method includes providing a plurality of scent spraying units containing original scents, heating the original scents via a heater, evaporating the original scents, and diffusing the evaporated scent with the air via an air supply pump. Thus, a desired scent can be transferred to a selected subject under correct concentration. The scent diffusion apparatus uses scent cartridges containing the original scents, such as cartridges used in an existing ink-jet printer, and uses the same control commands as those of a general personal computer or ink-jet printer compatibly. Thus, the scent diffusion apparatus can control an amount of diffusion precisely, be manufactured in a compact fashion, and used in connection with a general purpose computer in which almost all kinds of operating systems supporting an ink-jet printer are incorporated.

Scent diffusion apparatus and method

Growing community of inventors

Gyunggi-do, South Korea

Joong Ho Choi