Maximum allowed pulse width in 50hz push pull inverter

[azadfalah]

Hello friends,
Considering the possibility of current asymmetry in the branches of a center-tapped transformer used in a push pull converter

What is the maximum allowable pulse width to prevent transformer saturation?

*My schematic has a reset winding that is not in the schematic below.

Thanks

 

[BradtheRad]

Fifty percent duty cycle (per winding) is feasible if your load draws light current. Light load brings out the ramping-up effect as each pulse goes through the primary.

However the tendency is to load the secondary by taking greater Amperes, such that square waves go through the primary. In that event It's not easy to observe saturation. One indicator is when efficiency drops severely. Supply power reaches a point where the flux field fails to build beyond a maximum point. The excess power does not convey through the transformer.