Apparatus for direct measurement of capacitance and dissipation factor of capacitors

Claim 1

APPARATUS FOR CONTINUOUSLY MEASURING THE CAPACITANCE OF A CAPACITOR COMPRISING AN ALTERNATING CURRENT POWER SOURCE HAVING AN OUTPUT CURRENT SUBSTANTIALLY INDEPENDENT OF AN IMPEDANCE LOAD CREATED BY THE CAPACITOR UNDER MEASUREMENT, MEANS FOR CONTROLLABLY VARYING THE OUTPUT CURRENT OF SAID SOURCE, MEANS FOR CONNECTING SAID POWER SOURCE TO THE CAPACITOR UNDER MEASUREMENT, MEANS FOR DETECTING THAT PORTION OF THE VOLTAGE ACROSS THE CAPACITOR WHICH IS 90* OUT OF PHASE WITH THE CURRENT THROUGH THE CAPACITOR, A DIRECT CURRENT SOURCE, FEEDBACK MEANS CONNECTED TO THE OUTPUT OF SAID DETECTING MEANS AND SAID CURRENT VARYING MEANS FOR COMPARING THE OUTPUT SIGNAL THEREFROM WITH AN INDEPENDENT DIRECT CURRENT REFERENCE SIGNAL APPLIED THERETO SUPPLIED FROM A DIRECT CURRENT SOURCE COMNECTED TO SAID FEEDBACK MEANS BETWEEN SAID DETECTING MEANS AND SAID CURRENT VARYING MEANS AND FOR APPLYING ANY ERROR SIGNAL TO SAID CURRENT VARYING MEANS TO MAINTAIN CONSTANT THE QUADRATURE COMPONENT OF THE VOLTAGE ACROSS THE CAPACITOR, AND MEANS FOR MEASURING THE CURRENT THROUGH THE SAID CAPACITOR WHICH IS IN PHASE WITH THE QUADRATURE COMPONENT OF THE VOLTAGE THEREACROSS.