Cuk Topology

Little-known but still highly interesting
The topology of the Cuk converter was first published in the 1980s, but it is rarely encountered in practice even today.
However, this circuit concept offers enticing advantages for many power supply applications.
The Cuk converter is a capacitively coupled converter that generates an adjustable output voltage and current by periodically charging a capacitor. As the circuit (in its simplest form) does not provide electrical isolation between the input and output, it is suitable for secondaryside switched-mode power supplies or chargers.