AN-4140 Transformer Design Consideration for Offline Flyback Converters Using Fairchild Power Switch ( FPS TM ) 1
For flyback coverters, the transformer is the most important factor that determines the performance such as the efficiency, output regulation and EMI. Contrary to the normal transformer, the flyback transformer is inherently an inductor that provides energy storage, coupling and isolation for the flyback converter. In the general transformer, the current flows in both the primary and secondary winding at the same time. However, in the flyback transformer, the current flows only in the primary winding while the energy in the core is charged and in the secondary winding while the energy in the core is discharged. Usually gap is introduced between the core to increase the energy storage capacity.
Design, implementation and comparative analysis of an 18-pulse input flyback converter based switched mode power supply
Switch Mode Power Supply forms an integral component of the modern day power supply systems. Owing to multiple voltage conversion requirements, there is need for a SMPS system which not only mitigates the system harmonics but also provides an efficient and reliable power conversion. In this paper, an 18-pulse input fly-back converter based SMPS system has been proposed which intends to overcome the drawbacks associated with existing 18-pulse input power supply system, based on performance parameters and overall system cost. The proposed system has been designed, implemented and thoroughly analyzed using MATLAB Simulink. Also a comparative study with the existing system has been carried based on the obtained performance parameters.
Brushite-collagen composites for bone regeneration.
Brushite-based biomaterials are of special interest in bone regeneration due to their biocompatibility and biodegradability; on the other hand, collagen is a well-known osteoconductive biomaterial. In the present study a new brushite-collagen composite biomaterial is reported. This new biomaterial was prepared by combining citric acid/collagen type I solutions with a brushite cement powder. The obtained biomaterial was a cement paste, with improved handling properties. The effect of collagen on the setting reaction of brushite cement was studied, and was found to speed up the cement setting reaction. The cement paste set into a hard ceramic material within 18.5+/-2.1min and had compressive strength similar to that of spongeous bone (48.9+/-5.9MPa in dry conditions and 12.7+/-1.5MPa in humid conditions). The combination of collagen with citric acid revealed an interesting synergistic effect on the compressive strength of the composite material. Moreover, this new biomaterial had excellent cohesion properties (ninefold better than brushite cement), and high cellular adhesion capacity (threefold higher than brushite cement). The composite biomaterial described in this study combines good handling properties, compressive strength, cohesion and cell adhesion capacity, along with the osteoconductive and biodegradable properties inherent in brushite and in collagen-based biomaterials.