Inductive coupling circuit

Claim 1

A NUCLEAR RESONANCE DETECTION SYSTEM COMPRISING: THREE INDUCTORS, TWO OF SAID INDUCTORS BEING INDUCTIVELY COUPLED TOGETHER HAVING A MUTUAL INDUCTANCE OF M1, 2, A FRIST TERMINAL OF ONE OF SAID TWO INDUCTORS COMPRISING ONE TERMINAL OF A FIRST EXTERNAL CIRCUIT MEANS, A FIRST TERMINAL OF THE OTHER OF SAID TWO INDUCTORS COMPRISING ONE TERMINAL OF SECOND EXTERNAL CIRCUIT MEANS, A SECOND TERMINAL OF EACH OF SAID TWO INDUCTORS BEING ELECTRICALLY CONNECTED TOGETHER, A THIRD INDUCTOR HAVING AN INDUCTANCE L3 HAVING A FIRST END CONNECTED TO SAID COMMON TERMINAL BETWEEN SAID FIRST TWO INDUCTORS AND THE OTHER END SERVING AS A COMMON TERMINAL TO SAID FIRST AND SECOND EXTERNAL CIRCUIT MEANS, SAID THIRD INDUCTOR BEING FREE OF MUTAUL INDUCTIVE COUPLING WITH EITHER OF SAID FIRST TWO INDUCTORS WHEREIN THE INDUCTANCE OF SAID THIRD INDUCTOR IS SUBSTANTIALLY EQUAL AND OPPOSITE TO THE NUTUAL INDUCTANCE OF SAID FIRST INDUCTORS SATISFYING THE EQUATION:L3=-M1,2, A VARIABLE FREQUENCY A.C. GENERATOR MEANS FOR APPLYING A SIGNAL TO ONE OF SAID TWO EXTERNAL CIRCUITS, DETECTION MEANS CONNECTED TO THE OTHER OF SAID TWO EXTERNAL CIRCUITS, MEANS FOR CHANGING THE INDUCTANCE OF SAID THIRD INDUCTOR TO UNBALANCE THE SAID EQUATION WHEREBY ENERGY WILL BE COUPLED FROM SAID GENERATOR MEANS TO SAID DETECTION MEANS COMPRISING: A MAGNETICALLY POLARIZED NUCLEAR SAMPLE LOCATED WITHIN SIAD THIRD INDUCTOR, AND MEANS FOR VARYING THE FREQUENCY OF HE A.C. GENERATOR THROUGH A RANGE OF FREQUENCIES SUCH THAT WHEN A NUCLEAR RESONANT CONDITION OCCURS IN SAID SAMPLE, THE INDUCTANCE OF SAID THIRD INDUCTOR WILL VARY.