Abstract:
PURPOSE: A light emitting diode driving circuit is provided to reduce the size of a product by not requiring an additional sensing device and directly detect the voltage and current of an output terminal regardless of the on and off of a power switch. CONSTITUTION: An emitter of a switching element is respectively connected to an inductor, a capacitor, and a step-up/down controller(100). A sensing device is connected to the emitter of the switching device and one side of the capacitor. A diode is connected to the other side of the capacitor and a cathode. A start resistor is connected to the cathode of the diode. A light emitting diode is connected between the other side of the sensing device and the other side of the capacitor. The voltage of a sensing device is fed back to the step-up/down controller.
Abstract:
PURPOSE: An output voltage stabilizing circuit of a boost converter is provided to prevent an output voltage from exceeding an allowable range by forcedly applying a current source to an output terminal. CONSTITUTION: An inductor stores energy by the operation of a power switching device. A capacitor(C31) smooths the voltage outputted from a schottky diode. A serial resistor(R31,R32) divides the output voltage of the capacitor with a preset level. A control and drive unit(31) recognizes the level of the output voltage based on the feedback voltage and controls a power switching device to output the output voltage with a desirable level. A limit power voltage detector(32) outputs a switching control signal(CTL) by detecting the output voltage out of the allowable limit voltage based on the feedback voltage. A switching device(SW31) is turned on with a switching control signal and connects the terminal of the output voltage to a current source.
Abstract:
The present invention relates to a method and an apparatus for wirelessly transmitting power and an apparatus for wirelessly receiving power. According to an aspect of the present invention, the wireless power transmission apparatus transmits power through the mutual resonance of a source resonator and a target resonator; provides power to the source resonator from a power supply unit; and connects the power supply unit to the source resonator based on a control signal through a switching unit. In the said case, the switching unit may include a transistor and a diode.
Abstract:
PURPOSE: A rectifier for wireless power transmission and an input control method thereof are provided to reduce a load for controlling increased output of the rectifier by directly inputting alternating current power and to use an element having a low inner pressure when designing an application circuit connected to the rectifier for wireless power transmission. CONSTITUTION: A rectifier includes a rectifying unit(110), a load unit(120), and a comparing unit(130). The rectifying unit converts inputted alternating current power into direct current power and outputs the direct current power. The load unit is connected to an output terminal of the rectifier. The comparing unit senses an increase in the inputted alternating current power in the rectifying unit and controls the inputted alternating current power. [Reference numerals] (110) Rectifying unit; (120) Load unit; (130) Comparing unit
Abstract:
PURPOSE: A voltage and current bias circuit is provided to ensure stable operation by creating a voltage and a current with a constant output bias. CONSTITUTION: A transistor Q1 has a source connected to a line voltage terminal. A transistor Q2 has a drain electric current increase different from that of the transistor Q1. A transistor Q3 has a source connected to the drain of the transistor Q1. A transistor Q3 has a drain connected to the gate of the transistor Q1. A transistor Q4 has a source connected to the drain of the transistor Q2 and a gate connected to the gate of the transistor Q3.
Abstract:
PURPOSE: A light emitting diode drive circuit for illumination is provided to reduce EMI(Electro-Magnetic Interference) or EMC(Electro-Magnetic Compatibility) by reducing switching noise. CONSTITUTION: A bridge circuit part(410) outputs positive voltage from Vac voltage. A voltage detector(420) determines the size of input voltage. The voltage detector controls an upper switch(440) and a lower switch(450). A voltage-current converter(430) generates current proportional to the input voltage. The upper switch and the lower switch change a connection state of light emitting diode groups(460).
Abstract:
레벨 쉬프터, 상기 레벨 쉬프터를 포함하는 인버터, 및 레벨 쉬프팅 방법이 개시된다. 상기 레벨 쉬프터는 제1 입력신호에 기초하여 제1 전압 또는 제2 전압을 제1 출력전압으로서 출력하고, 제2 입력신호의 상승에지 또는 하강에지에 기초하여 래치신호를 생성하는 제1 출력 전압발생부; 및 상기 래치신호에 기초하여 전하를 충전하고 충전된 전하와 상응하는 전압을 제2 출력전압(V OUT_H )으로서 출력하는 제2 출력 전압발생부를 포함할 수 있다. 본 발명에 의하면, 레벨 쉬프터를 소형으로 제작할 수 있고 동작 특성을 향상시킬 수 있는 효과가 있다. 레벨 쉬프터, 인버터