New topologies of fully regulated two-output dc-to-dc converters with small frequency variation range

This paper offers a new solution to the design of two-output dc-to-dc converters having one sole power transistor. The combination of a resonant converter and a tapped-inductor converter is the basis of this new approach which represents an improvement on previous studies. The fact that the dc voltage gain of the resonant converter is a function of the switching frequency but not of the load nor of the duty cycle and the fact that the tapped-inductor converter is a function of the duty cycle but not of the frequency nor of the load, enables the two outputs to be regulated with only small switching frequency variations and with only slight interaction between the two outputs. A prototype of this converter has been built and the results are discussed.