Power electronics is the technology associated with efficient conversion, control and conditioning of Electrical Power from its available input into the desired electrical output form. This book is concerned of electrical power processing using electronic devices the key component of which is a switching DC-DC power converter.Electric power generated from renewable energy sources is getting increasing attention and supports for new initiates and developments in order to meet the increased energy demands around the world.Power electronics is an integral part of the power processing and delivery from the energy sources to the utility supply and the electricity consumers. This text book introduces DC-DC converters with using soft switching technology step up voltage from low level to high level with reducing losses and modulation techniques.