Samsung Electro-mechanics Co., Ltd.

University of Seoul Industry Cooperation Foundation

Solum Co., Ltd.

Jae Shin Lee

Bo Hyun Hwang

Jung Sun Kwon

Sang Hyun Cha

Deuk Hee Park

Seung Kon Kong

Joon Youp Sung

Jung Hyun Kim

Dae Hoon Han

Seo Hyung Kim

Joong Ho Choi

Yun Joong Lee

Chang Seok Lee

Yeun Joong Lee

Jung Eui Park

Yong Seong Roh

Change Seok Lee

Jung Chul Gong

Chang Sik Yoo

Yu Jin Jang

Young Jin Moon

Jeong Mo Yang

Kang Yoon Lee

Joo Hyung Lee

Gyu Hyeong Cho

Hong Jin Kim

Chang Bae Lee

Changsik Yoo

Youn Joong Lee

Jeong In Cheon

Jong Tae Hwang

Jin Yong Jeon

Jun Hyeok Yang

Hyun Sik Kim

Seung Ryung Ryu

Ho Joon Jang

Yung Jin Moon

There is provided a multi-output power supply capable of maintaining power balancing between multiple output powers by fixing a switching duty until a voltage level reaches a predetermined voltage level during an initial stage of a soft-start operation, the multi-output power supply including a power supply unit switching an input power and outputting a plurality of powers having levels determined according to the switching, and a controller controlling a soft switching operation of the power supply unit during an initial operation and fixing a switching duty of the power supply unit to a preset switching duty according to a result of a comparison between a preset reference voltage level and an operating voltage determining whether the soft switching operation is performed or not during the soft switching operation.

Multi-output power supply

There is provided a multi-output power supply apparatus capable of maintaining multiple output voltages in a balanced state by limiting a variable range of a switching duty according to a load state. The multi-output power supply apparatus includes: a power supply unit switching input power to output a plurality of voltages whose power levels are determined according to the switching operation; and a controller detecting power states of at least some of the plurality of voltages from the power supply unit, and limiting a range of a switching duty of the power supply unit to a pre-set range when the detected power states correspond to a pre-set limited power state.

Multi-output power supply apparatus enhancing a power imbalance between multiple outputs

There is provided a power supply apparatus capable of precisely control a primary side switching frequency at a secondary side by receiving fed-back information regarding a power state at the secondary side without a separate expensive circuit or a complicated circuit. The power supply apparatus includes: a power supplying unit having a primary side and a secondary side having different ground electrical characteristics, switching power input to the primary side, and transferring the switched power to the second side electrically insulated from the primary side to supply the power; a controlling unit provided on the secondary side and receiving fed-back information regarding a power state of the power supplying unit to control a maximum value and a minimum value of a switching frequency of the primary side; and a transferring unit transferring a control signal from the controlling unit to the primary side of the power supplying unit.

Power supply apparatus

Disclosed herein are a PWM control circuit, a flyback converter, and a PWM control method. The PWM control circuit includes: a peak storing and reference signal generating unit storing a peak value of one period of a feedback signal from a secondary side output and inverting the peak signal and outputting the inverted peak signal as a reference signal; and a PWM control signal generating unit generating a PWM control signal by using an output obtained by comparing the reference signal with a reference waveform from the peak storing and reference signal generating unit. In addition, the flyback converter including the same and the method for controlling PWM are proposed.

PWM control circuit, flyback converter and method for controlling PWM

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

There is provided a light emitting diode driving apparatus capable of uniformly maintaining current balance between light emitting diode channels. The light emitting diode driving apparatus includes: a DC to DC converting unit converting the direct current power into settable driving power; a detecting unit detecting voltage drops generated in each of a plurality of light emitting diode channels each having a plurality of light emitting diodes; a converting unit converting an analog value into a digital value; and a driving unit differentially setting duty cycles of switching signals according to the digital values from the converting unit to drive the plurality of light emitting diode channels.

Light emitting diode driving apparatus

There is provided an apparatus for driving a light emitting diode (LED), capable of distributing current stress applied to the LED. The apparatus includes an LED part including a plurality of LED units respectively including at least one LED, the plurality of LED units being connected in parallel to a power input terminal to which rectified power in sine wave form is supplied, and, among the plurality of LED units connected in parallel, a termination end of the LED unit in a front end being connected to a middle of an adjacent LED unit; and a current source unit including a plurality of current sources respectively connected to termination ends of the plurality of LED units and allowing corresponding current to flow through the plurality of LED units.

Apparatus for driving light emitting diode

There is provided a light emitting diode driving apparatus, including: a power supplying unit converting input power into driving power according to a control and supplying the converted driving power to a light emitting diode channel; a driving unit controlling current flowing in the light emitting diode channel according to a pulse width modulation (PWM) dimming signal from the outside; and a controlling unit comparing a reference level set by a duty of the PWM dimming signal with a detection voltage level of the light emitting diode channel and controlling a power converting operation of the power supplying unit according to the comparison result.

Provided is a PWM driving circuit and a PWM driving method. The PWM driving circuit includes a dimmer switching unit turning on a first switch to apply a first reference signal varied according to an input voltage of a system when an output voltage level of a dimmer is a reference level or less, and turning on a second switch to apply a second reference signal, unrelated to the input voltage of the system, when the output voltage level of the dimmer is more than the reference level, an error amplification unit comparing the first reference signal or the second reference signal with an output detection signal to amplify an error and outputting an error amplification signal, and a PWM control signal generating unit comparing the error amplification signal of the error amplification unit with a predetermined reference waveform to output a PWM control signal.

PWM driving circuit and PWM driving method

Disclosed herein is a light emitting diode (LED) driving apparatus including: at least one energy storages connected in series with each other; a plurality of LEDs each connected in parallel with each of the energy storages; and a switching control unit selectively connecting the at least one energy storages according to a level of applied voltage to charge/discharge voltage in/from the selected energy storages and control driving of the LEDs by the charging/discharging operation. Therefore, it is possible to easily drive the LEDs without a converter.

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 are provided an LED driving apparatus and an LED driving method thereof. The LED driving apparatus includes: a light emitting unit including one or more LEDs, a rectifying unit rectifying an input signal to generate a first signal; a signal conversion unit inverting a waveform of a first signal to generate a second signal; and an operation unit arithmetically operating the first and second signals. A plurality of AC signals each having a different waveform are arithmetically operated to generate a signal having a small amount of a ripple component, and an LED is driven by the signal, thus preventing a lifespan of the LED from being shortened by omitting a smoothing electrolytic capacitor, one of main causes shortening the lifespan of an LED driving circuit.

LED driving apparatus and method

Provided is an LED driving apparatus. The LED driving apparatus includes a plurality of LED groups each comprising one or more diodes, a switch group comprising a plurality of switch units connected respectively to the LED groups to drive the connected LED group when a control signal is activated, and a switch controlling unit configured to compare an input voltage of the LED groups with an output voltage of the LED groups, calculate a comparison value, and generate the control signal according to the comparison value. Accordingly, the LED driving apparatus drives the LED groups selectively according to the difference between the input voltage of the LED group and the output voltage of the LED group, thereby overcoming the problem of heat generation by forward voltage distribution.

There is provided an LED circuit including a light emitting unit including a plurality of light emitting diodes; and a switching unit switching to apply only positive voltage of an AC power supply to an anode of the light emitting unit. Through this, the LED circuit can reduce complexity of a driving circuit. Further, lifespan and efficiency of the LED circuit may be improved since an electrolytic capacitor and a bridge circuit are not used. Further, any one light emitting diode may be prevented from determining the lifespan of all of the light emitting diodes since all of the light emitting diodes are driven at all times, thereby improving the lifespan of the light emitting diode.

Growing community of inventors

Gyunggi-do, South Korea

Jae Shin Lee