A modified Series-Capacitor  ( SC )  High Conversion Ratio  ( HCR )  dc-dc converter is proposed. The proposed converter inherits most of the advantages of the existing SC HCR dc-dc converter and can eliminate the problem of high switch-voltage stress of the existing converter encountered during start-up using a simple circuit modification. Capacitor is required in the proposed converter, total series capacitance of the proposed converter is the same as that of the conventional SC converter. In addition, input capacitance of the proposed converter can be reduced by less than half of that of the SC buck converter. A 1 kW prototype converter is built and tested to verify the performance of the proposed converter. All the converters are derived based on the two basic converters such as buck converter and boost converter. The aims of developing the converters are high efficiency and high gain with fast response. Today’s world demands the low power application devices which is the focus of the researchers. There are so many parameters are involved while developing those converters. A lot of computer software has been developed to design such type of converters. With the help of simulations, the behavior of the system can be easily analyzed without any hardware which can prevent the damage.