KR-20260062675-A - LLC RESONANT CONVERTER FOR LED LAMP AND LIGHTING APPARATUS USING THE SAME

KR20260062675AKR 20260062675 AKR20260062675 AKR 20260062675AKR-20260062675-A

Abstract

The present invention relates to an LLC resonant converter for an LED lamp and a lighting device using the same. More specifically, the invention relates to an LLC resonant converter for an LED lamp and a lighting device using the same, which can improve EMI and efficiency while supplying constant current to an LED lamp by including a filter unit that prevents overvoltage with respect to an input AC voltage, a first rectifier unit and a second rectifier unit that convert the AC voltage into a DC voltage, and a resonant LLC converter unit that prevents blinking while maintaining a high power factor. To solve the above problem, the LLC resonant converter for an LED lamp and the lighting device using the same according to the present invention comprises: a filter unit that filters overvoltage and noise included in an input AC power source; a first rectifier unit that converts the AC power source filtered by the filter unit into a pulsating DC power source and outputs a smoothed pulsating DC power source; and a second rectifier unit that supplies the smoothed power source converted by the first rectifier unit as a constant voltage DC power source. The system is composed of an LLC resonant converter unit that outputs the DC power output from the second rectifier unit as the operating power for the LED lamp, wherein the LLC resonant converter unit includes: a control IC that generates a square wave using switching and controls the driving of the switching; a resonant tank that generates resonance by the switched square wave of the control IC; a transformer that converts the square wave output from the resonant tank into the operating power for the LED lamp; and a rectifier circuit that rectifies and smooths the operating power for the LED lamp output from the transformer.

Inventors

문재호

Assignees

주식회사 케이비텍

Dates

Publication Date: 20260507
Application Date: 20241029

Claims (6)

A filter section that filters overvoltage and noise included in the input AC power supply; A first rectifier that converts the AC power filtered by the above filter unit into pulsating AC power and smooths and outputs the converted pulsating AC power; A second rectifier that supplies the smoothed power converted by the first rectifier as a constant voltage DC power; and LLC resonant converter unit that outputs the DC power output from the second rectifier unit as the operating power for the LED lamp; It consists of, The above LLC resonant converter section is, A control IC that generates a square wave using switching and controls the driving of the switching; A resonance tank that generates resonance by the switched square wave of the above control IC; A transformer that converts a square wave output from the above-mentioned resonant tank into an operating power source for the above-mentioned LED lamp; and A rectifier circuit that rectifies and smooths the operating power of the LED lamp output from the transformer; LLC resonant converter for LED lamps including
In claim 1, The above control IC is, A first control module including a first switching element and controlling the duty cycle of a square wave based on the output resonant current; and A second control module including a second switching element and removing residual ripple current in the first control module during the operation time when the first switching element of the first control module is turned ON; LLC resonant converter for LED lamps including
In claim 2, The above-mentioned first control module is composed of an outer terminal and an inner control unit, wherein The above terminal is, It is composed of a floating reference terminal (HB1), a second control module driving terminal (LX1), a power supply terminal (VB), a current sensing input terminal (CS), and a drain terminal (HV1), and The above control unit is, A current feedback unit that limits or feeds back the sensing current value based on the sensing current value input to the above current sensing terminal (CS) and converts to a formal mode; A current adjustment unit that adjusts the current based on the feedback current value of the above current feedback unit; A PWM correction unit that corrects a PWM signal based on the sensing current value of the current feedback unit and the adjustment current of the current adjustment unit; A first driver unit that drives the on/off of the duty cycle based on a PWM signal adjusted by the above PWM correction unit; A second control module driving unit that outputs a PWM signal adjusted by the above PWM correction unit to the second control module driving terminal (LX1); and A first switching element (SW1) in which the drain is connected to the drain terminal (HV), the gate is connected to the first driver unit, and the source is connected to the floating reference terminal (HB1); LLC resonant converter for LED lamps including
In claim 3, The above second control module is composed of an outer terminal and an inner control unit, The above terminal is, It is composed of a start terminal (HV2) connected to the floating reference terminal (HB1) of the first control module to receive the operation of the first control module, a power supply terminal (VCC), a drive terminal (LX2) connected to the second control module drive terminal (LX1) of the first control module, a ground terminal (GND) connected to ground, and a drain terminal (HB2). The above control unit is, A start unit that outputs a start signal to an operation signal input to the start terminal (HV2); A voltage compensation unit that compensates the voltage of a signal input from the above driving terminal (LX2); A driver logic unit that determines drive logic based on the start signal of the above start unit and the voltage compensated by the above voltage compensation unit; A second driver unit that drives on/off to eliminate ripple current based on logic determined by the above driver logic unit; and A second switching element (SW2) in which the drain is connected to the drain terminal (HB2), the gate is connected to the second driver unit, and the source is connected to the ground terminal (GND); LLC resonant converter for LED lamps including
In claim 1, The above LLC resonant converter section is an LLC resonant converter for LED lamps composed of a half bridge.
A lighting device using an LLC resonant converter for an LED lamp according to any one of claims 1 to 5.

Description

LLC Resonant Converter for LED Lamp and Lighting Apparatus Using the Same The present invention relates to an LLC resonant converter for an LED lamp and a lighting device using the same, and more specifically, to an LLC resonant converter for an LED lamp and a lighting device using the same that can improve EMI and efficiency while supplying constant current to an LED lamp by including a filter section that prevents overvoltage with respect to an input AC voltage, a first rectifier section and a second rectifier section that convert the AC voltage into a DC voltage, and an LLC resonant converter section that prevents blinking while maintaining a high power factor. LEDs (Light Emitting Diodes) have the advantages of being smaller and having a longer lifespan compared to conventional light sources, as well as consuming less power and being highly efficient because electrical energy is directly converted into light energy. Due to these characteristics, they are gaining popularity as lighting devices that replace conventional incandescent or fluorescent lamps, not only for display devices in various electronic equipment but also for indoor and outdoor lighting, signage lighting, and general residential lighting. In order to use LEDs in lighting devices, LED modules composed of multiple LEDs are used, and these LED modules must be supplied with a constant current to emit light properly and maintain their lifespan. Since the LED module of the above LED lighting uses a DC power supply, a switching mode power supply (hereinafter referred to as 'SMPS') is used to rectify the commercial AC power supply of 220 volts into DC and convert the rectified DC voltage into a DC voltage of the required size. Meanwhile, as the adoption of high-power home appliances expands, the 'blinking' phenomenon in LED lamps is emerging as a concern for LED lighting manufacturers. The aforementioned blinking refers to a phenomenon in which LED lights momentarily flicker when inverter (pulse) type heating appliances, such as bidets, induction cooktops, and instant water heaters, are turned on or off. This is caused by a short-duration voltage sag, which fluctuates the instantaneous voltage input to the SMPS. While momentary voltage drops affect LED lights and other home appliances, the blinking phenomenon is easily visible to the user and has been regarded as a defect in LED lighting devices. Accordingly, as a technology for detecting abnormalities in the input power supply, Registered Patent Publication No. 10-2345908 discloses an input power supply abnormality and self-fault detection SMPS circuit and an LED converter device including the same. The above technology includes a fuse connected to an input AC power source; a first shunt resistor and a second shunt resistor connected in parallel to each end of the fuse; a rectifier diode with one end connected to the connection point of the first shunt resistor and the second shunt resistor; a third resistor connected in parallel to the other end of the rectifier diode; a first capacitor connected in parallel to the other end of the rectifier diode; a second capacitor connected in parallel to the other end of the rectifier diode; and an output section connected to both ends of the second capacitor. In addition, as a technology for preventing light flickering caused by rapid load fluctuations, Registered Patent Publication No. 10-2353592 discloses a driving circuit for an LED lighting device equipped with a function to prevent light flickering caused by rapid load fluctuations of a high-power electrical device. The above technology includes: a filter circuit that receives commercial power and filters and stabilizes the voltage of the input power; a rectifier circuit that rectifies and smooths the stabilized AC voltage into DC voltage; a transformer circuit that converts the rectified and smoothed DC voltage into a set voltage magnitude and outputs it according to an input control signal; an oscillation circuit that generates the rectified and smoothed DC voltage according to a control signal; a constant voltage control circuit that cancels out the transient voltage of the power output from the oscillation circuit by constant voltage control; and a constant current control circuit that cancels out the transient current of the power output from the constant voltage control circuit by constant current control and outputs it to the power output terminal connected to an LED module. FIG. 1 is a configuration diagram of an LLC resonant converter for an LED lamp according to the present invention. FIG. 2 is a circuit diagram according to one embodiment of an LLC resonant converter for an LED lamp according to the present invention, FIG. 3 is a circuit diagram of an LLC resonant converter section applied to an LLC resonant converter for an LED lamp according to the present invention. FIGS. 4 and FIGS. 5 are block diagrams of a first control module and a second control module applied to an LLC resonant co