In the world of switching DC/DC converters the Zeta topology is a lesser known relative of the SEPIC topology. Both converters provide a positive output voltage that can be greater than, equal to or less than Vin while avoiding the complexity and cost of a buck-boost converter. The Zeta converter however, has the advantage of significantly reduced output ripple voltage.
By varying the duty cycle of the mosfet we can increase or decrease the DC input voltage by a factor of D/(1-D) (where D is the duty cycle). In the example we have set the duty cycle at 66.7% so with 10V at the input we expect that after the transients settle out to have 20V at the output.
If you want to change the duty cycle just change the
width of all voltage pulse sources (6.67% is 66.7% duty cycle and 10% is 100% duty cycle).
