Samsung Electro-mechanics Co., Ltd.

Jong Rak Kim

Hyo Young Kim

Sung Hun Oh

Jin Hwan Kim

Min Jin Kim

Ju Rae Kim

Kyoung Ho Yoon

Jung Heyn Park

Sang Kyoo Han

Sung Soo Hong

Chung Wook Roh

Yoon Seok Seo

Won Sik Chong

Jeong Hyun Park

Sug Chin Sakong

Young Gun Hong

Gie Hyoun Kweon

Hoy Young Kim

Suh Woo Choi

There is provided a boost converter capable of reducing voltage stress within each element thereof, without using a separate loss snubber circuit, by clamping a voltage applied to an output diode to correspond to a difference between an input voltage and an output voltage. The boost converter includes a transformer including a primary winding receiving an input power and a secondary winding electromagnetically coupled to the primary winding and having a preset turn ratio therewith; a switching unit switching the input power transferred to the primary winding on and off according to a preset duty ratio; a stabilizing unit including an output diode rectifying the power outputted from the secondary winding to stabilize an output power; and a clamping unit clamping a voltage applied to the output diode to correspond to a difference between the input power and the output power during a switching on operation of the switching unit.

Boost converter for reducing voltage stress

There are provided a current balance circuit having a protection function that prevents the current balance circuit from being damaged during a preset time period by maintaining a constant level of power being supplied to the lamp, and a power supply. The current balance circuit having the protection function includes a current balance unit maintaining current balance of lamp driving power supplied to a lamp unit including a plurality of lamps, and a protection unit detecting the lamp driving power supplied to the lamp unit from the current balance unit, cutting-off the lamp driving power after a preset time period when the lamp operates abnormally, and controlling a voltage level of the lamp driving power to a preset reference voltage level or lower during the preset time period.

Current balance circuit having protection function, and power supply

A lamp driving circuit includes a first printed circuit board and a second printed circuit board. The first printed circuit board includes a switching unit for switching an input power source, a control unit for controlling the switching unit, an inverter transformer connected to the switching unit, and a voltage conversion unit for converting a feedback reference current for controlling an output current applied from the inverter transformer into a reference voltage and applying the reference voltage to the control unit. The voltage conversion unit is connected to the inverter transformer and the control unit. The voltage conversion unit is connected to a first feedback terminal. The second printed circuit board includes a plurality of balance coils connected to a plurality of lamps so that the same output currents are applied to the lamps, a second feedback terminal connected to the first feedback terminal, and a current conversion unit connected to the second feedback terminal.

Lamp driving circuit

The present invention relates to a light emitting device (LED) driving apparatus that constantly maintains the average current flowing onto a plurality of channels. The light emitting device (LED) driving apparatus includes: a LED light source unit in which at least one LED channel is connected in parallel; at least one current detector that is disposed on a low end of a LED channel of the LED light source unit to detect the current flowing onto respective LED channels; at least one channel current controller that generates control signal controlling the average current of the channels by comparing current detected from the channels with reference wave; and a switching element that controls the average current of the LED channels in a PWM scheme according to the control signals.

Light emitting device driving apparatus and method for driving the same

The present invention provides a connector including: a printed circuit board including a guide hole and a locking hole; a plurality of connection pads provided on a top surface of the printed circuit board; a housing which is mounted on the printed circuit board and including a guide inserted into the guide hole and a locking unit inserted into the locking hole, which are protrudingly formed on a bottom surface of the housing; a plurality of terminals inserted and fixed into the housing so that one ends are positioned inside the housing and the other ends are projected to an outside of the housing; and terminal units in contact with top surfaces of the connection pads by being connected to the one ends of the terminals inside the housing.

Connector

In accordance with the present invention, a multi-output transformer includes a primary bobbin provided with one primary winding unit with one input terminal and one ground terminal; a secondary bobbin provided with n(n: positive integer) number of secondary winding units with two output terminals respectively; a primary coil wound around the one primary winding unit; secondary coils wound around each of the n secondary winding units; and a pair of cores inserted into insertion holes formed inside the primary bobbin and the secondary bobbin respectively to separate the primary bobbin and the secondary bobbin.

Multi-output transformer

There is provided a backlight unit having a protection circuit using a center-tap, the backlight unit including: a current balancing unit including a plurality of primary coils individually transmitting the lamp driving power from an inverter unit to the lamps, and a plurality of secondary coils each formed of one conductor having a center-tap, and receiving an electromagnetically induced voltage from each of the plurality of primary coils, the one end and the center-tap of each of the plurality of secondary coils connected in series with the one end and the center-tap of the neighboring secondary coil to form at least one closed loop and maintain current transmitted to each of the lamps balanced; a sensing unit sensing a variation in current of the closed loop and a variation in current of the primary coil from the current balancing unit; and a determination unit determining whether each of the lamps performs an abnormal operation or not.

Backlight unit having protection circuit using center-tap

There is provided an integrated type transformer that reduces the volume by integrating a plurality of transformers transmitting power for driving a plurality of lamps in an inverter circuit for an LCD into one transformer structure. An integrated type transformer according to an aspect of the invention includes a bobbin unit including a bobbin body having a predetermined length and a through hole therein in a longitudinal direction of the bobbin unit, and a core unit including an inner core inserted into the through hole of the bobbin unit, and an outer core formed along one surface in the longitudinal direction among outer circumferential surfaces of the bobbin unit and electromagnetically coupled to the inner core to form one magnetic path.

Integrated type transformer

There is provided a backlight unit that determines whether a lamp performs an abnormal operation by detecting a voltage that is induced in a power conversion transformer without using a complicated and expensive detection circuit. A backlight unit having a protection circuit using induced voltage detection according to an aspect of the invention includes an inverter part including a primary coil receiving power and at least one secondary coil converting the power from the primary coil to AC power set beforehand, a lamp part including at least one lamp receiving the AC power from the inverter part to emit light, a detection part including conductors detecting voltages electromagnetically induced in the secondary coil, and an abnormality determining part comparing detection voltages from the detection part with a reference voltage set beforehand.

Backlight unit having protection circuit using induced voltage detection

A backlight inverter using electromagnetic induction and full-wave rectification at a second side of a main transformer includes a drive unit for generating a first voltage and a main transformer having first and second coils. The main transformer converts the first voltage from the drive unit into a second voltage, and outputs an AC current of the second voltage to both ends of a lamp. An auxiliary transformer has a first auxiliary coil formed on a current line connecting between the second coil of the main transformer and the lamp and a second auxiliary coil inductively coupled with the first auxiliary coil. The auxiliary transformer detects the current flowing to the lamp. A full-wave rectifier rectifies the current detected by the auxiliary transformer, and a drive controller controls the PWM duty of the first voltage based on a voltage from the full-wave rectifier.

Backlight inverter for inductively detecting current

The present invention relates to a transformer. In the transformer, secondary winding sections are placed in both sides of a primary winding section, all terminals of the secondary winding sections are used as output terminals, and an input terminal is placed in the opposite side to the output terminals. Therefore, a return wire in the high-voltage output side does not need to be provided, and a sufficient insulation separation distance is secured in the relation with a printed circuit board, which makes it easy to implement a circuit. Further, improved efficiency is obtained over a conventional transformer, there is a significant reduction in cost, and products using the transformer can be small in size. The transformer includes a bobbin composed of one primary winding section having one input terminal and one ground terminal and 2n (n: positive number) secondary winding sections, each secondary winding section having two output terminals; a primary coil wound around the primary winding section; secondary coils wound around the 2n secondary winding sections; and a pair of cores that are respectively inserted into an insertion hole formed inside the bobbin.

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Gyunggi-do, South Korea

Jong Rak Kim