Radiation hardened magnetic voltage and/or current reference produced by a saturable, two core transformer with first harmonic nulling

A magnetic based reference to produce a stable voltage or current and comprising:

• magnet means to generate a magnetic field;
• magnetic field detector means to sense the magnetic field generated by said magnet means and provide an AC output signal that is indicative of the sensed magnetic field;
• said magnetic field detector means including a saturable core transformer comprising at least two magnetic cores, each of said magnetic cores having a respective primary and secondary winding wound therearound and a common control winding wound therebetween, the primary windings of said cores being interconnected with one another and the secondary windings of said cores being interconnected with one another, and each of said primary windings being in phase with one another and each of said secondary windings being in phase opposition with one another;
• means responsive to the output signal from said magnetic field detector means to provide a fed back current to the control winding which is wound between the cores of the saturable core transformer of said detector means by which to cancel the magnetic field sensed thereby;
• load means to receive the fed back current provided to said control winding, such that the current through said load means and the voltage across said load means produce said stable current and voltage, respectively;
• AC voltage source means for providing an AC input voltage signal to the primary windings of the cores of said saturable core transformer;
• first variable impedance means connected across the primary winding of a first of the two magnetic cores of said saturable core transformer and second variable impedance means connected across the primary winding of the second magnetic core;
• and
• means responsive to the output signal generated by said detector means by which to adjust the impedance of said first and/or second variable impedance means such that the parallel impedance of said first variable impedance means and the primary winding of said first magnetic core is equal to the parallel impedance of said second variable impedance mans and the primary winding of said second magnetic core to thereby null the first harmonic of the AC input voltage signal, such that the AC output signal provided by said magnetic field detector means is the second harmonic of said AC input voltage signal.