I m studying a flyback converter. The flyback converter is already made. I m just trying to understand how it works. I m actually focusing on the flyback transformer. And in order to better understand how it is designed I need to know if it is working in Continuous Current Mode or in Discontinuous Current Mode. It is a flyback transformer with fractionnal turns. Here is the formula that I used for knowing if it working in CCM or DCM, the formula is not the best ... It is obtained by doing the approximation that the the transformer is ideal... If you have a better formula it would be really nice to hear it !
In the above formula I know each of the parameters, except Vs which is the output voltage of a transformer with one input and one output. Ve is the rectified input from a RMS 230V.
My transformer has several outputs. How can I know Vs ? What I have done : I estimated the power and the current of each output. Then I sum all of this for having the total output power and the total output current for having the "average" output voltage. What do you think about this method ? Do you have any advice ?
The result is a current which is very low (about 30 mA) where as the ouput power is about 40 W and the total current drawn is around 2A5. The primary inductance is about 1.5 mH. The frequency is around 75 KHz. I am relatively surprised that the limit between CCM and DCM is so low ...
Here is what I called a fractionnal transformer (the windings are fractionned in several outputs) (This is not the transformer that I m studying) :
Thank you very much :)