Samsung Electro-mechanics Co., Ltd.

Jae Han Yoon

Dong Kyun Ryu

Peel Sik Jeon

Seung Heun Yang

Ki Mok Kim

Won Chan Choi

Jeong Rak Lee

Kyung Hyun Kim

Sung Uk Lee

Yun Seop Shin

Tai Sung Kim

Kyung Su Han

Nam Su Koo

An apparatus for driving a light emitting part includes a DC/DC converter for supplying an amplified driving voltage to the light emitting part; a constant current circuit for controlling a current flowing through the light emitting part; a converter controller for controlling the DC/DC converter and the constant current circuit; a current sensor for sensing and converting a current flowing to an anode of the light emitting part into a voltage; a feedback controller for controlling a feedback current according to a magnitude of the voltage from the current sensor; an optical coupling part for performing optical coupling to transmit the feedback current as a feedback voltage; and a main controller for determining whether an over-current is occurring according to a magnitude of the feedback voltage and stopping an operation of the converter controller when the over-current is occurring.

Apparatus for driving light emitting device with over-current and over-voltage protection

There is provided an alternating current (AC) detection circuit for power supply, the AC circuit including: a rectifying part rectifying an AC voltage; a voltage division part dividing the voltage rectified by the rectifying part according to a preset division ratio; a voltage stabilization circuit part stabilizing the voltage divided by the voltage division part; and a first square wave generating part comparing the voltage stabilized by the voltage stabilization circuit part with an internal reference voltage, and generating a first square wave signal having a duty ratio according to comparison results between the stabilized voltage and the internal reference.

AC detection circuit for power supply

Provided is a switching mode power supply circuit for plasma display panel, which includes an EMI filter unit, a PFC unit, an output unit, and a standby unit. The EMI filter unit may include a first line filter connected to a commercial line input power, a first capacitor and discharge resistor connected to the first line filter, a second line filter connected to the first capacitor and discharge resistor, a second capacitor connected to the second line filter, and a relay unit disposed between the first line filter and the first capacitor and discharge resistor. The standby unit may be connected to a contact point of the first line filter and the relay unit.

Switching mode power supply circuit for plasma display panel

The present invention relates to a switching mode power supply circuit for a plasma display panel comprising an input unit, a PFC (Power Factor Correction) unit, an output unit and a standby unit, wherein the standby unit includes a standby block for outputting a standby voltage by being connected to an AC filter stage of the input unit, a sequence block for sequentially applying power of the output unit and a control block which is connected between the standby block and the sequence block and inputs the standby voltage outputted from the standby block to the sequence block only in case that a PS_ON signal is applied.

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Jeollabuk-do, South Korea

Jae Han Yoon