The converter is an electrical device which converts direct current (DC) to alternate current (AC). The converter is used for emergency backup power in a home. The converter is used in some aircraft systems to convert a portion of the aircraft DC power to AC. The AC power is used mainly for electrical devices like motor, radio, lights and other devices. DC-DC power supplies (which is also called a linear converter or switching regulator) have a small solution size in order to operate and save space. In order to produce the regulated voltage, the power supply should be able to boost up the battery voltage from as low as the battery voltage when it is higher than the required output voltage. Fully encapsulated in a metal case with an isolated baseplate the railway DC-DC converters have an industry standard. The linear the converter has many advantages, such as input to output DC insulation, buck-boost capability, and continuous output current, but it is difficult to control.