Converters perform their functions using power electronics (solid-state semiconductor) devices periodically switched on and off at certain frequency. Numerous circuit topologies have been developed for these converters, and new ones are evolving every year. A number of computer software programs, such as PSPICE and SABER, are available to analyze such converters in great detail. However, the following sections present the basic circuits and the voltage, current, and power relationships at the input and output terminals of some widely used converters, leaving details for more advanced books dedicated to the subject of power electronics.