Patent ID: 9055619
Filing Date: 2015-06-09
Classification: H05B

Abstract:
1. In an electrical ballast system having a rippled DC source driving a toroidal current transformer with a core having an exterior surface, a primary winding, and two secondary windings with said primary winding connected in series to a lamp load circuit conducting a current with varying amplitude and said secondary windings connected to two transistors' gate, the improvement comprising a semi gap in said core extending from said exterior surface a predetermined distance and said semi gap having two opposing surfaces that converge interiorly in said core wherein said semi gap defines two opposing surfaces in said core disposed at an angle with respect to each other that extends from 40 to 50 degrees defining a wedge-like reduced core area to limit the output voltage amplitude of said secondary winding to a predetermined voltage amplitude limit compatible with said transistor gates when said reduced core area is magnetically saturated, keeping a linear relationship between said current and said output voltage up to said limit, and keeping a non-linear relationship between said current and said output voltage after said limit so that said output voltage is attenuated sufficiently to minimize the use of power-limiting protective circuits and wasted energy.