Direct-reading carrier frequency impedance meter

Claim 1

A DIRECT-READING CARRIER FREQUENCY IMPEDANCE METER CONSISTING OF AN INTERNAL VARIABLE-FREQUENCY SOURCE OF ALTERNATING CURRENT, A STANDARD RESISTANCE UNIT, EXTERNAL TERMINALS FOR CONNECTING AN UNKNOWN COMPLEX IMPEDANCE IN SERIES WITH SAID CURRENT SOURCE AND SAID RESISTANCE UNIT, THE IMPEDANCE VALUES OF SAID RESISTANCE UNIT AND SAID UNKNOWN IMPEDANCE BEING OF COMPARABLE MAGNITUDE, DIFFERENTIAL-AMPLIFIER MEANS CONNECTED ACROSS SAID STANDARD RESISTANCE UNIT, THE OUTPUT OF SAID DIFFERENTIAL-AMPLIFIER MEANS PROVIDING A REFERENCE PROPORTIONAL TO THE CURRENT THROUGH SAID STANDARD RESISTANCE UNIT, A REFERENCE-LEVEL INDICATING MEANS CONNECTED WITH THE OUTPUT OF SAID DIFFERENTIAL-AMPLIFIER MEANS; CURRENT-DIVIDING MEANS CONNECTED IN SERIES WITH SAID DIFFERENTIAL-AMPLIFIER MEANS FOR PROVIDING PARALLEL ELECTRICAL CIRCUITS A AND B; A 90-DEGREE PHASESHIFTING DEVICE FOR VARIABLE FREQUENCIES IN SAID B CIRCUIT, SAID PHASE-SHIFTING DEVICE CONSISTING OF TWO R-C SECTIONS IN WHICH THERE IS A 45-DEGREE PHASE SHIFT EACH, SAID R-C SECTIONS EACH CONTAINING A VARIABLE CAPACITOR THE CONTROL MEANS OF WHICH IS GANGED WITH THE CONTROL MEANS OF SAID INTERNAL VARIABLE-FREQUENCY SOURCE OF ALTERNATING CURRENT IN A MANNER SUCH THAT THERE IS A DEPENDENT AND INVERSELY PROPORTIONAL RELATIONSHIP BETWEEN THE CAPACITANCE OF EACH OF SAID VARIABLE CAPACITORS AND THE FREQUENCY OF SAID INTERNAL VARIABLE-FREQUENCY SOURCE OF ALTERNATING CURRENT WHEREBY THE REACTIVE IMPEDANCE OF SAID VARIABLE CAPACITORS IS MAINTAINED CONSTANT THROUGHOUT THE OPERATING RANGE OF SAID CONTROL MEANS OF BOTH SAID INTERNAL VARIABLEFREQUENCY SOURCE OF ALTERNATING CURRENT AND SAID VARIABLE CAPACITORS IN SAID R-C SECTIONS; WAVE-SHAPING MEANS IN EACH OF SAID A AND B CIRCUITS ENERGIZED BY CURRENT IN SAID RESPECTIVE A AND B CIRCUITS FOR PRODUCING A SUCCESSION OF SQUARE WAVES HAVING A DURATION OF ONE-HALF ALTERNATING CURRENT CYCLE AND SPACED BY INTERVALS OF ONE-HALF ALTERNATING-CURRENT CYCLE; AMPLIFYING AND PHASE-INVERTING MEANS FOR DERIVING A PUSH-PULL SIGNAL PROPORTIONAL TO THE VOLTAGE DROP ACROSS SAID UNKNOWN COMPLEX IMPEDANCE; CURRENT-DIVIDING MANS CONNECTED IN SERIES WITH SAID AMPLIFYING AND PHASE-INVERTING MEANS FOR PROVIDING PARALLEL PUSH-PULL CIRCUITS C AND D; GATED-AMPLIFIER MEANS IN EACH OF SAID C AND D CIRCUITS, THE CATHODES OF SAID GATED-AMPLIFIER MEANS IN SAID C CIRCUIT BEING CONNECTED TO THE SQUARE-WAVE VOLTAGE DERIVED FROM SAID A CIRCUIT, AND THE CATHODES OF SAID GATED-AMPLIFIER MEANS IN SAID D CIRCUIT BEING CONNECTED TO THE SQUARE-WAVE VOLTAGE DERIVED FROM SAID B CIRCUIT; A FIRST DIRECT-CURRENT MICROAMMETER ELECTRICALLY CONNECTED IN THE PLATE CIRCUIT OF THE GATEDAMPLIFIER MEANS IN SAID C CIRCUIT WHEREBY THE DEFLECTION OF SAID MICROAMMETER BY THE DIRECT-CURRENT COMPONENT IN THE OUTPUT OF SAID GATED-AMPLIFIER MEANS IN THE C CIRCUIT IS DIRECTLY PROPORTIONAL TO THE RESISTANCE OF SAID UNKNOWN COMPLEX IMPEDANCE; A SECOND DIRECT-CURRENT MICROAMMETER HAVING A ZERO-CENTER SCALE ELECTRICALLY CONNECTED IN THE PLATE CIRCUIT OF THE GATED-AMPLIFIER MEANS IN SAID D CIRCUIT WHEREBY THE POSITIVE AND NEGATIVE DEFLECTION OF SAID ZERO-CENTERED MICROAMMETER BY THE DIRECTCURRENT COMPONENT IN THE OUTPUT OF SAID GATED-AMPLIFIER MEANS IN THE D CIRCUIT IS DIRECTLY PROPORTIONAL TO THE INDUCTIVE AND CAPACITIVE REACTANCE RESPECTIVELY OF SAID UNKNOWN COMPLEX IMPEDANCE.