A calibration method of the zero-drift for testing system of electronic transformer characteristics

Drift problem exists widely in electronic transformer test systems, and is found to have significant effect on describing the steady state characteristics and dynamic characteristics for electronic transformer. The output offset and drift problem of the high-performance and high-precision amplifier is the major cause leading to a drift in characteristic testing system. In this paper, a mixed automatic drift compensation method for dc amplifiers has been presented. By using hardware circuit to measure the drift, with software algorism compensation for several times, the drift of the electronic transformer test system has been solved. The proposed method has been verified by developing an electronic transformer test system.