Abstract: There is provided a light emitting diode power supply apparatus capable of limiting a rise in a voltage level of a power supplied to a light emitting diode even in the case in which driving of the light emitting diode is stopped for a long period of time. The light emitting diode power supply apparatus includes: a power supply unit supplying a driving power set under a control to a light emitting diode; and a controlling unit selecting one of a detection voltage obtained by detecting a current flowing to the light emitting diode and a voltage provided according to an operation state of the light emitting diode to control a power supply operation of the power supply unit.

Abstract: 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.

Abstract: There are provided a power supply apparatus switching a 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 generating a predetermined PWM signal to apply the generated PWM signal to a dimming switch connected to an end of the load and controlling a switching frequency of the primary side based on a control voltage generated according to a feedback signal depending on the power supplied to the load and the PWM signal, wherein a voltage variation amount of the control voltage may be constantly maintained regardless of a duty of the PWM signal.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: The present invention relates to a light emitting diode driver that integrates a light emitting diode control function and a power switching control function at a secondary side insulated from a primary side in a power supply circuit, without using a photo coupler to control power switching at the primary side.

Abstract: 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.

Abstract: The present, invention relates to a light emitting diode driver that integrates a light emitting diode control function and a power switching control function at a secondary side insulated from a primary side in a power supply circuit, without using a photo coupler to control power switching at the primary side.