LED flood light 50won August 9th, 2012 at 7:23 AM
Abstract: This paper presents a work in discontinuous mode (DCM) dual-output, single-stage flyback power factor correction (PFC) converter drive method of the bright high power LED. In order to avoid the cross effects of the converter two outputs, the application of time-division multiplexing method independent adjustment of each output branch current, improve the reliability of the drive; this method is only used in a magnetic component to achieve two-way constant stream output, thereby reducing the cost of the drive; converter operating in DCM, fixed-frequency, fixed duty cycle, the availability of high power factor. Finally, simulation and experiment to verify the correctness and validity of the results of this study.
Today, LED 120w has been widely used in LCD backlighting, automobiles, traffic lights and general lighting. According to IEC 61000-3-2 C-class regulations, the need for LED general lighting greater than 25W drive power factor correction (Power of high power LED 1w Factor Correction PFC), low-cost power factor correction program to become concerned about the research topic.
AC / DC converter, active Power Factor Correction (Active PowerFactor Correction. APFC) circuit is a two-stage PFC circuit, before a circuit is used for power of LED 3w factor correction, after the stage as a DC / DC converter. Due to the existence of two cascaded power stage, this type of circuit size and cost is usually higher, and therefore, there have been other APFC topology such topology PFC circuit and DC / DC converter are integrated, they share active power switch, a single-stage AC / DC converter, thus reducing the cost of this APFC circuit is now widely used in the ballast in the charger.
Multi-output converter as LED 10w driver can be realized with a converter to meet the needs of a number of different levels of constant current output, thereby reducing the cost of the drive. Traditional multi-output converter, such as transformer coupling method, the weighted feedback regulation can achieve constant voltage output of the multi-channel multi-channel constant current output, but can not be achieved. Based on this, this paper proposes a dual output single-stage Flyback PFC topologies.
Such topology in DCM to achieve a constant voltage output of the brightest independent regulator, but also realize the brightest independent constant-current output regulation and power factor correction. In order to avoid the cross effects of the converter two outputs, the application of time-division multiplexing method independent adjustment of each output branch current, which allows each drive different types of LED flood light 50w , and drive the way in which failure will not affect the other slip of the normal output, improve the reliability of the drive; Because this method is only used in a magnetic component to achieve a two-way constant current output, does not require high voltage energy storage capacitor after the rectifier bridge, thereby reducing the cost of the drive. Converter operating in DCM, fixed-frequency, fixed duty cycle, but also to obtain a higher power factor. Finally, through simulation and experimental verification of the correctness and validity of the results of this study.