NOVEL METHOD OF MEASUREMENT OF L AND C

A novel method of measurement of component values of inductors and cap acitors is described. The technique is independent of the voltage acro ss or current through the unknown inductor or capacitor, as it involve s only a set of phase measurements. The unknown capacitor/inductor is connected in series with a known standard resistance and this series c ircuit is excited by a source of required voltage and frequency. The r esistive and reactive parts of the unknown component are measured by m easuring the phase displacement between the three voltages, namely, vo ltage applied, voltage across the inductor/capacitor and the voltage a cross standard resistance. The proposed scheme is verified both by sim ulation as well as by building a prototype. The relationship between t he range of the measurement and obtainable accuracy level is establish ed. For the prototype built, with a one decade span in the measurement range, a commercially acceptable accuracy of +/-2.0% was achieved. Ho wever, this accuracy can be further improved by suitable circuit modif ications.