A Flicker-free Electrolytic Capacitor-less AC-DC LED Driver
• The concept of flicker-free electrolytic capacitor-less ac-dc driver for LED lighting is proposed which consists of:
• An electrolytic capacitor-less PFC converter
• A bidirectional buck/boost converter
Proposed Circuit
• A Fly-back converter at DCM is utilized as PFC.
• The bidirectional buck/boost converter is
• chosen as the bidirectional converter because of the simplest
circuit.
A Method of Reducing the Peak-to-Average Ratio of LED Current for Electrolytic Capacitor-Less
AC–DC Drivers
• A method of injecting the third and fifth harmonics into the input current to reduce the peak-to-average ratio of the output current is also proposed.
• A 25 V, 0.35 A output prototype is built and tested in the laboratory, and the experimental results are presented to verify the effectiveness of the electrolytic capacitor-less LED driver and its control method.
A Method of Reducing the Peak-to-Average Ratio of LED Current for Electrolytic Capacitor-Less
AC–DC Drivers
• There is a conflict that if the input power factor is unity, the peak-to-average ratio of the output current is 2;
• And if the peak-to-average ratio of the output current is to be reduced to 1, the input power factor will be zero.
• Therefore, the trade-offs must be balanced.
• This is achievable by injecting some odd harmonics into the input current to reduce the peak-to-average ratio of the output current, while maintaining the input power factor to be higher than 0.9 as required by the regulation standards.
Design of Boost-Flyback Single-Stage PFC Converter for LED Power Supply without Electrolytic Capacitor
for Energy-Storage
• This paper presents the concept of applying large voltage ripple for energy storage into the Boost-Flyback Single Stage PFC converter for the elimination of the electrical capacitor.
Electronic Driver without Electrolytic Capacitor for Dimming High Brightness LEDs
• The converter, operating with a peak current control, keeps the current through the LEDs constant independently of the bus voltage.
• This is carried out internally by self-adjusting the switching frequency of the converter.
Elimination of an Electrolytic Capacitor in AC/DC Light-Emitting Diode (LED) Driver With High Input
Power Factor and Constant Output Current
Elimination of an Electrolytic Capacitor in AC/DC Light-Emitting Diode (LED) Driver With High Input
Power Factor and Constant Output Current
• A 13.5W prototype was designed with PFC:
A Novel Valley-Fill SEPIC-derived Power Supply Without Electrolytic Capacitors for LED Lighting Application
A Novel Valley-Fill SEPIC-derived Power Supply Without Electrolytic Capacitors for LED Lighting Application
A Novel Valley-Fill SEPIC-derived Power Supply Without Electrolytic Capacitors for LED Lighting Application
A Novel Valley-Fill SEPIC-derived Power Supply Without Electrolytic Capacitors for LED Lighting Application
A Novel Valley-Fill SEPIC-derived Power Supply Without Electrolytic Capacitors for LED Lighting Application
A Universal-Input High-Power-Factor PFC Preregulator without Electrolytic Capacitor for PWM Dimming LED Lighting
Application
A Universal-Input High-Power-Factor PFC Preregulator without Electrolytic Capacitor for PWM Dimming LED
Lighting Application
A Universal-Input High-Power-Factor PFC Preregulator without Electrolytic Capacitor for PWM Dimming LED
Lighting Application
A Universal-Input High-Power-Factor PFC Preregulator without Electrolytic Capacitor for PWM Dimming LED
Lighting Application
Cost-Effective Hundred-Year Life for Single-Phase Inverters and Rectifiers in Solar and LED Applications Based on MinimumCapacitance
Requirements and a Ripple Power Port
Cost-Effective Hundred-Year Life for Single-Phase Inverters and Rectifiers in Solar and LED Applications Based on Minimum
Capacitance Requirements and a Ripple Power Port
Cost-Effective Hundred-Year Life for Single-Phase Inverters and Rectifiers in Solar and LED Applications Based on Minimum
Capacitance Requirements and a Ripple Power Port
Current Source Ballast for High Power Lighting Emitting Diodes without Electrolytic Capacitor
Rated Power
Current Source Ballast for High Power Lighting Emitting Diodes without Electrolytic Capacitor
40% Power