Flyback converter derivation of Vin/Vout

Ian0

Joined Aug 7, 2020
13,097
In a flyback converter why do we assume that $\Delta I_{on}=\Delta I_{off}$?
So that the average input current remains constant.
I assume you are referring to a boost converter with a single-winding inductor, not an isolated flyback converter with a multi-winding inductor.
 

BobTPH

Joined Jun 5, 2013
11,463
What would hapoen if it was not the case?

Suppose dI/dt x t(on) was greater than dI/dt x t(off). What would the current look like over time?
 

Thread Starter

Samantha Groves

Joined Nov 25, 2023
151
Yes something else as well:

I am trying to understand how
So that the average input current remains constant.
I assume you are referring to a boost converter with a single-winding inductor, not an isolated flyback converter with a multi-winding inductor.
No im refering to a flyback converter with a isolated output.
 

Thread Starter

Samantha Groves

Joined Nov 25, 2023
151
I have one more question:I have been studying for a exam for quite some time and here are my notes

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The result in the last equation according to the videos I have been watching is wrong it should be ND/1-D.Where am I wrong?I cant find my error.
 
Last edited:

Ian0

Joined Aug 7, 2020
13,097
I have one more question:I have been studying for a exam for quite some time and here are my notes

View attachment 315259
The result in the last equation according to the videos I have been watching is wrong it should be ND/1-D.Where am I wrong?I cant find my error.
First thoughts say that it is because there is no current in the primary when current flows in the secondary, and vice versa, but I‘ll have to think about it!
 
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