Apparatus for stabilizing high-gain direct current transistorized summing amplifier

Claim 1

A STABILIZED OPERATIONAL AMPLIFIER COMPRISING A HIGH GAIN TRANSISTORIZED AMPLIFIER COUPLED TO PASS DIRECT CURRENTS FROM AN INPUT TERMINAL TO AN OUTPUT TERMINAL THEREOF, A FEEDBACK RESISTOR COUPLED BETWEEN THE OUTPUT TERMINAL AND AN INPUT SUMMING JUNCTION, AN INPUT SUMMING RESISTOR COUPLED TO PASS INPUT SIGNALS TO THE SUMMING JUNCTION, A SPURIOUS CURRENT DETECTING IMPEDANCE COUPLED BETWEEN THE SUMMING JUNCTION AND THE INPUT TERMINAL OF THE HIGH GAIN AMPLIFIER, SAID DETECTING IMPEDANCE BEING OPERABLE TO ESTABLISH AN ERROR POTENTIAL AT SUMMING JUNCTION CORRESPONDING TO SPURIOUS CURRENTS WHICH MAY EXIST AT THE INPUT TERMINAL OF THE HIGH GAIN AMPLIFIER TO CAUSE UNDESIRABLE DRIFT IN THE SIGNAL PASSED BY THE HIGH GAIN AMPLIFIER, A DRIFTLESS DIRECT CURRENT COUPLED AMPLIFIER COUPLED BETWEEN THE SUMMING JUNCTION AND THE INPUT TERMINAL OF THE HIGH GAIN AMPLIFIER, SAID DRIFTLESS AMPLIFIER BEING OPERABLE TO GENERATE AN OUTPUT CURRENT FOR EFFECTIVELY CANCELLING THE SPURIOUS CURRENT AND IN RESPONSE TO THE ERROR POTENTIAL APPEARING AT THE SUMMING JUNCTION WHEREBY THE SIGNAL PASSED BY THE OPERATIONAL AMPLIFIER IS STABILIZED WITH RESPECT TO DRIFT RESULTING FROM THE SPURIOUS CURRENT, AND A SECOND DRIFTLESS DIRECT CURRENT COUPLED AMPLIFIER COUPLED TO THE HIGH GAIN AMPLIFIER AND RESPONSIVE TO SPURIOUS POTENTIALS AT THE INPUT TERMINAL THEREOF, SAID SECOND DRIFTLESS DIRECT CURRENT COUPLED AMPLIFIER HAVING AN OUTPUT TERMINAL COUPLED TO THE HIGH GAIN AMPLIFIER FOR STABILIZING SIGNALS PASSED BY THE OPERATIONAL AMPLIFIER WITH RESPECT TO DRIFT CAUSED BY SAID SPURIOUS POTENTIALS.