Off-line, Half-bridge Converter

Output ripple voltage Output regulation Cost target  

This is going to be a eurrent-mode eontrolled half-bridge topology. It will have soft-start to minimize the start-up surge of the system. The power supply must meet UL, CSA, and VDE safety regulations. 

It is deeided that the power supply will operate at an operating frequency of 100 KHz, and the controller IC will be an MC34025R 

I will be using an E-E core since it has the largest wire area of all the core styles. The large wire area will be needed for all the additional insulating layers required for the VDE certification. No air-gap is needed for bipolar forwardmode converters. The core material is going to be 3C8 (Ferroxcube) or F (Magnetics, Inc.) material. This material will yield reasonable core losses at this frequency. 

The estimated core size for this application is approximately 1.3 inches (33 mm) on each side. The closest sized core is Magnetics part number F-43515. I will request that core and also F-44317, which is the next core size larger, just in case the windings grow beyond the limits of the window area. 

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A Zero Voltage Switched Quasi-resonant Off-line Half-bridge Converter... 

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