SPICE-aided design of a variable inductor in LED driver applications

This paper presents a design, simulation and evaluation procedure of a variable inductor (VI) for a recently proposed DC-grid LED driver. The design procedure is based on the use of SPICE behavioral modelling to implement the different elements of the equivalent reluctance model of the VI. Thus, the model merges both electrical and magnetic behavior of the VI, including magnetic and geometric features. The basic components of the model are presented in detail, making it possible their use in future designs of VI and other complex magnetic devices. Experimental results from both VI and LED driver prototypes are provided to compare with the simulation results. Obtained outcomes prove that the proposed design and modelling technique is an excellent way to verify theoretical designs and attain further insight about the operation of these complex magnetic devices.