Buck-Boost converter

hi clever ppl .. i am designing a buck-boost converter on simulink... i have an input of 50v and i want an output of 12v.... using these parameters i have calculated the duty cycle which is 0.19...can someone plss help me calcuate the values of C and L in the circui.....RL is 5ohms...i have attached the circuit if the helps...

Whatever your circuit does, I don't believe it will give you +12V out.

Why are you trying to design a buck-boost converter? Unless you need a output voltage greater than the input voltage you only need a buck converter.

What is Rs?

is jus resistor to represent the resistance on the wire

whu!, glad you cleared that up, and I thought the Rs resistor was just to limit the short circuit created by the coil.