How do you calculate the output voltage of a discontinuous inductor boost converter?
That's the problem &mdash; a discontinuous-mode boost converter with no feedback does not have a well-defined output voltage.

Depending on the on time of the switch during each cycle, the value of the inductance and the input voltage, a certain amount of energy is stored in the coil. When the switch opens, this energy is dumped to the output. If the output is only a capacitor, the capacitor voltage will rise indefinitely until something breaks down.

If there's a resistance, the output voltage and current will rise until the average power dissipated matches the input power (energy per switching cycle &times; switching frequency).

With this type of converter, if the load is variable, then you have to use feedback to vary the input power to match, usually by varying either the duty cycle or the frequency of the switching (or sometimes both).