Forward Converter - Voltage through primary winding Question
The magnitude seems right to me, but the time should not be \$t_{off}\$, but \$\frac{1}{5} t_{on} \$ instead, because the demagnetization ends five time faster than the magnetization during the ON period (due to 5 times bigger reset voltage). After that there is no magnetizing current, the diode D3 stops conducting and the voltage stays zero across the windings.