Patent ID: 6803776
Filing Date: 2004-10-12
Classification: G01R

Abstract:
A current comparator-based bridge for measuring accurately an electrical parameter of an unknown element having two current terminals and two potential terminals, said bridge comprising:a current source for serially flowing a first electrical current through the unknown element and a current comparator; a buffer circuit bridging the unknown element and a reference element, each having two current terminals and two potential terminals for flowing a second electrical current through a reference resistor, a current sensing element and the current comparator; said buffer circuit having first and second buffers and being adapted to equalize voltage drop between the potential terminals of the unknown element and voltage drop between the potential terminals of the reference element, a quadrature circuit connected to the sensing element for generating a quadrature component of the second electrical current through the current comparator; and a controller circuit for controlling and sensing an ampere-turn balance in the current comparator to derive the electrical parameter of the unknown element in relation to the reference element.