voltage issue with push pull transfomer

[EMitter]

Hi all,

I am using push pull transformer in my project which accepts 48v input and produces 600v output voltage but here in design my transformer is not producing 600v if i apply 48v at the primary side ,instead it is producing 220v. And also if i look at the the voltage at primary its drops from 48v to 20v.
Transformer voltage ratio is 1:12

Here i am driving push pull transformer using mosfet which takes pulse as shown in figure.

Please say where i am going wrong.

thank you.

 

[ronsimpson]

What are the values for the parts? R, C =? What diode? What transistors?
What transformer? Part number? Data sheet?

if i look at the the voltage at primary its drops from 48v to 20v.

Is the VCC48 dropping to 20V?
Why do you pulse each gate 6 times?
I do not understand D5, D6?

 

[dr pepper]

A push pull trans doubles the voltage at the primary, so if you want 600v out from 48 in then 1:6 would be closer.

Does the voltage on the fets drop to zero when they are on?

Have you left headroom flux density wise in the transformer primary calcs, ie are you sure the trans isnt saturating.

 

[KeepItSimpleStupid]

Frequency? Is the transformer core OK for the frequency your operating at?

 

[ronsimpson]

The core is probably in saturation.

 

[RCinFLA]

One problem with power push pull configuration like this is perfect balance between the duty cycle to the two MOSFET's. If the duty cycle is just a bit longer on one half the cycle there will be a magnetic bias that builds up in the core saturating it.

There are several techniques to modulate the duty cycle correction feedback system to ensure balance on the core. Most involve an extra winding that is used for the feedback correction.

 

[dr pepper]

Depending what control ic you use you can have dc component from the control ic, esp if the load current has an ac waveform, I think rc just touched on this.
A cap in series with the trans common might be a good idea.

You can put a low ohm resistor inline wth the trans common and 'scope it, you'll be able to see if the trans is saturating, and if theres a significatnt dc component across the primary.