Silvio
Well-known member
Hi Pichou
I still do not know your input voltage but I am assuming it is 12v (correct me if I am wrong)
It will be better to put 2 snubbers across each primary winding (Your topology is push pull from what I can see)
You can also fit an 18v zener across drain source so that any voltage generated during switch off will be shorted out with the zener
Try lower capacitance with your snubber like 10nf and work out again the resistor value
Through experience I found that when the pwm is working in full duty not much noise is generated and usually the output inductor is not needed, this can generate a spike back to the primary winding. This is why the secondary snubber is needed
Having spikes in your wave forms can disturb the operation of the pwm signal to the gates
You need to use better symmetry in your trafo try to interleave the windings together if possible Primary and secondary side by side and wound together to the best possible way due to different turns in each winding.
I still do not know your input voltage but I am assuming it is 12v (correct me if I am wrong)
It will be better to put 2 snubbers across each primary winding (Your topology is push pull from what I can see)
You can also fit an 18v zener across drain source so that any voltage generated during switch off will be shorted out with the zener
Try lower capacitance with your snubber like 10nf and work out again the resistor value
Through experience I found that when the pwm is working in full duty not much noise is generated and usually the output inductor is not needed, this can generate a spike back to the primary winding. This is why the secondary snubber is needed
Having spikes in your wave forms can disturb the operation of the pwm signal to the gates
You need to use better symmetry in your trafo try to interleave the windings together if possible Primary and secondary side by side and wound together to the best possible way due to different turns in each winding.