This paper presents a low-cost and a low power auxiliary DC-DC converter for regulating the inductance of main power inductor of power electronic converters. A Variable Inductor (VI) is a current controlled power inductor which can be used for improving the performance of power electronic converters. Particularly in applications with dynamic load variations, this device can be very beneficial in reducing the core size, and the current ripple in power electronic converters. In this paper a digitally controlled 12V-3V buck converter is built in order to provide a controlled current for regulating the effective inductance of the power inductor and its performance is validated through experimental evaluation.