Transformer for SMPS

[JJMI]

I have tried to make a transformer for my SMPS for a while, but all of these tend to saturate. I saw my distributor carries standard toroid transformers for the use with 115 or 230 VAC. I was wondering if I could use a 50VA backwards, of course with the proper winding ratio. If I could do this, will a 50VA be suitable for switching 40A at 12v with a 100kHz DC-DC controller?

Thank You,
JJMI

 

[jbartos]

Suggestion: It depends. The consumption of DC-DC controller should be obtained first. Any additional foreseeable load should be added. Some design margin should be added, e.g. 15%.

 

[i8flipper]

Hi there,
Why don't you try using a ferrite core from an old television. You can't use a standard iron core to make your transformer at those frequencies.(ie hysteresis)
I built a PWM DC to DC power supply back in college using a ferrite core out of a TV, it worked very well.

Good luck