# High Frequency Transformer

Discussion in 'The Projects Forum' started by Peytonator, May 11, 2011.

1. ### Peytonator Thread Starter Active Member

Jun 30, 2008
105
3
Hi there,

I built a high frequency transformer:

• f = 80kHz (square wave)
• 15 primary turns, 45 secondary (turns ratio 3)
• Ferrite core
All my calculations tell me that I'm not loading the source or saturating, but I get strange waveforms on the primary and secondary.. I can't seem to post the image (too big), but the positive plateau slopes downwards and the negative upwards. It does a little kink at each transition. What's going wrong and how do I fix this?

Thanks

2. ### kubeek AAC Fanatic!

Sep 20, 2005
4,687
805
Is that a halfbridge? If you can´t post images here, post it for example on imageshack a put here the link.

Jul 7, 2009
1,585
141
There are a gazillion free programs out there to resize pictures for you. IrfanView is one.

4. ### wayneh Expert

Sep 9, 2010
12,376
3,226
It's an inductor. What makes you think anything is wrong?

Dec 26, 2010
2,147
300
It sounds as if the primary inductance is too low. Do you know the Specific Inductance (Al) value of the core?

The inductance is given by L = N$^{2}$ * Al , so with N=15 you would have L = 225 * Al.

Dec 26, 2010
2,147
300
Right enough, how important is it to preserve flat tops and bottoms anyway - and for that matter, how much tilt are we talking about: 10%, 50%, or what?

I think you are going to need to get to grips with posting images.