Front-end circuit apparatus for impedance measurements and the like

摘要

This disclosure is concerned with a novel front-end circuit for impedance measuring circuits and the like, involving separately or alternately operated grounding switches for connecting the free terminals of unknown and standard impedances, series-connected at a common terminal, to ground, for enabling separate selected voltage measurements between the unknown and standard, and with the series-connected impedances fed from a floating transformer; the circuit avoiding errors due to low switch impedances and obviating dependence upon capacitance from either side of the unknown impedance to ground and upon the series impedance involved in connections or leads to the unknown impedance.