A Series Resonant Converter (SRC-series resonant converter) with a bridge inverter according to its power part structure is similar to classical converters with voltage inverters. A series resonant circuit consisting of induction and capacity is referred to specific elements of the diagram. Due to resonance the processes in SRC power circuit acquire harmonic character. However, resonant phenomena lead to additional division of operating cycle into intervals and origination of various SRC operating modes on altering of converter's frequency or inverter's pulse width. The number of possible modes increases upon the use of active power valves in the rectifier. Therefore it is reasonable to define a connection between SRC's switching algorithms and its operating modes.