This paper compares controllers in non-Isolated d.c. - d.c. converter. To maintain a constant voltage is not possible in open loop. To achieve with the help of PI, neural and fuzzy controller. This paper shows three methods neural is the best among the other two. Neural network is giving more output voltage with free from ripple content. This circuit is operating without transformer, to reduce the size, space, weight cost and free from ripple. It is used in charging and discharging in buck mode, speed control of d.c. motor, UPS d.c. servo motor, telecom aircraft and automobiles. The open loop circuit is analyzed with all the passive filters. This circuit is different from other existing d.c.-d.c. step-up converters and possess many advantages including high output voltage with reduced ripple and wide range of control. The open loop is implemented with hardware and simulation results are verified. The performance evaluation of the controllers is tabulated.