Comments on Flyback converter design
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Flyback converter design
Hi guys,I'm designing a multiple output flyback converter with 2 outputs at 10v@1 Amp and 5v @ 2 Amps .Input is 20 V dc
Im having some problem with the implementation of closed loop. Open loop response comes out fine but i dont know how to control two outputs with a single control loop.
Any help would be much appreciated. Im using Spice simulation(ltspice) and matlab simulink.
If anyone have some simulation files or schematics , it would be immensely helpful.
Thank you
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Try searching for "multiple outputs flyback". Basically, you can't control each, individually, instead you make the voltage feedback as the average between the outputs. Here's a quick'n'dirty test to show what I mean, with a simple voltage mode concoction (don't give it too much thought for the values, they work enough for this example):
R3, R4, and R5 form a combined resistive divider which make the averaged value of the outputs appear at their junction. This is the one that the loop considers to follow. The disadvantage is that whatever perturbation exists on one output, only, will affect the other(s), too: R2 is the load for the 24 V (give or take) jumps from 50 Ω to 150 Ω, and you can see how the 12 V output drops a little. It's still stabilized, but it's the average of the outputs that is monitored, not any output in particular.
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