Many applications require DC/DC conversion. So many, that it is estimated that the world market will exceed 35 billion dollars by 2020. But for many circuit designers, the DC/DC converter is a “black box”; a component to fulfil a function just like other components such as inductors or transistors. As a general purpose functional block, DC/DC converters can be used everywhere and anywhere they may be needed; there is no “typical” area of application. This final section explores some of the more unusual ways in which DC/DC converters can be used to illustrate just how wide the field of applications for DC/DC converters is.