A parallel resonant constant current power supply

In the past, resonant converters have generally been analyzed and characterized for constant output voltage power supplies. When applied to power supplies, in which output current is regulated, the topological requirements of a resonant converter differ. This means, a resonant converter topology not suitable for constant voltage power supplies may become attractive for constant current power supplies. This fact is illustrated here. The operation of a parallel resonant converter (PRC) as a constant current power supply is presented. A PRC operating at resonant frequency gives constant output current. If designed properly, the output current can become nearly independent of load over a wide range of switching frequency. Repeated simulations and laboratory experiments on prototype converter verify the analysis.