Patent ID: 6262563
Filing Date: 2001-07-17
Classification: G01R,Y10S

Abstract:
Apparatus for evaluating admittance of an electrochemical cell or battery at a discrete frequency comprising:current excitation circuitry adapted to be coupled to said cell or battery and adapted to pass a periodic current through said cell or battery, said periodic current characterized by a smallest period equal to the reciprocal of said discrete frequency;current sensing and processing circuitry coupled to said current excitation circuitry and adapted to provide a current signal in response to said periodic current;voltage sensing and processing circuitry coupled to said cell or battery and adapted to provide a voltage signal in response to a periodic voltage across said cell or battery;current sampling and converting circuitry coupled to said current sensing and processing circuitry and adapted to provide digital representations of sampled values of said current signal, said sampled values obtained at discrete current sampling times synchronized with said periodic current and uniformly distributed in time over half-period or full-period intervals of said smallest period of said periodic current;voltage sampling and converting circuitry coupled to said voltage sensing and processing circuitry and adapted to provide digital representations of sampled valves of said voltage signal, said sampled values obtained at discrete voltage sampling times synchronized with said periodic current and uniformly distributed in time over half-period or full-period intervals of said smallest period of said periodic current; and,computation and control circuitry coupled to said current excitation circuitry, to said current sampling and converting circuitry, and to said voltage sampling and converting circuitry, said computation and control circuitry adapted to initiate said current sampling times, to initiate said voltage sampling times, and to numerically combine said digital representations of said sampled values of said current signal and said digital representations of said sampled values of said voltage signal to evaluate said admittance.