Magnification of the input impedance of a magnetizing winding by electronic means

The problem of reducing the exciting current drawn by a winding for establi shing flux in a magnetic core has been receiving considerable attention ove r the years. Conventionally, quality materials of high permeability and low loss have been employed for this purpose. The 'two-stage' principle has al so been applied along with buffer amplifiers for increasing the input imped ance, especially of inductive voltage dividers. In this paper, we propose a n alternative electronic feedback compensation technique employing an i-to- i converter for achieving the above goal in both single-core and two-stage arrangements. A quantitative analysis of the circuit is presented to determ ine the factor of improvement attainable in the two cases. Experimental res ults on a model, two-core arrangement are provided, to establish the feasib ility of the proposed technique.