New DC-DC converters with an energy storage reactor

New DC-DC power converters with an energy storage reactor are presented. In the conventional converter circuits of an energy storage reactor, there is an extraordinary increase of the output voltage due to the excess magnetic energy, when the reactor current becomes discontinuous for the light-load. This phenomenon can be removed by making use of a dummy load or a reactor of sufficiently large inductance. However, the use of the dummy load makes the efficiency poorer and the size as well as the weight becomes larger if the inductance of the reactor is increased. In the converter circuits presented, the excess magnetic energy, which is stored in the reactor and undissipated in the load circuit, can be recovered to the input power source through the additional transistor and diode. With these converter circuits, the dummy load can be removed for any load condition and further the inductance of the reactor can be made smaller.