Patent ID: 8710847
Filing Date: 2014-04-29
Classification: G01R,H03F

Abstract:
1. A battery testing device to automatically compensate for DC offsets arising from the battery testing device, comprising: an input terminal to receive an excitation response signal comprising a DC bias and an AC response; an op amp coupled to receive and to amplify the response signal, the op amp introducing internal errors manifested in the amplified response signal; a servo integrator coupled to receive the amplified response signal and to determine the DC bias and a rate of change of the amplified response signal, and in response, to produce a servo feedback signal to compensate for the DC bias; a correction circuitry, coupled to receive the servo feedback signal and to output a correction current to the op amp, and to produce the correction current in order to remove the DC bias; an error sensing device, coupled to receive the correction current and to output a feedback control signal, to adjust for the internal errors introduced by the correction circuitry; and an output terminal to output a corrected AC signal.