I have built an AC/AC cuk converter for an assignment I am doing. It works as such, I provide 50V AC in and I get an adjustable voltage out from 0V to 50V AC, depending on the duty cycle of the PWM that I gate to the MOSFETs. I have included a schematic below, drive circuit as not been shown.
![IMG](http://i59.tinypic.com/1ze8obc.png)

It works extacly as I have explained. However, I would like to incorporate some sort of rudementry simple short circuit protection.

Any ideas would help, thanks.