Current balancing circuit for use with chromatographic system detector

Abstract

An improvement is disclosed for use in a chromatographic system of the type including detector means providing a detector output signal indicative of the level of a component sought to be determined, detector output amplifier means for receiving the signal, an error signal balancing loop connected to the amplifier output to provide a balancing signal in feedback relationship to the amplifier, and means for adjusting the sensitivity range of the amplifier. The improvement, which enables adjustment of the error signal through the feedback loop, comprises control means connected in the feedback loop for varying the sensitivity range of the amplifier in accordance with a desired mode of system operation, the control means providing a bit correction pattern for feeding into the feedback loop in accordance with the output signal of the amplifier; digital-to-analog conversion means in the loop for converting the bit stream pattern to a first resolution level; and resistor network and switching means in the feedback loop for further resolving the error signal output from the digital-to-analog conversion means, and providing the further resolved signal in feedback relationship to the amplifier to effect balancing of same.

Dependencies are inferred from the claim text.