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The inductive sensor arrangement for detecting metal objects hidden in a surrounding medium comprises a pair of field coils for generating an alternating magnetic flux by a sequential excitation with an AC-current and a pair of sense coils respectively mounted inside each associated field coil in an

The inductive sensor arrangement for detecting metal objects hidden in a surrounding medium comprises a pair of field coils for generating an alternating magnetic flux by a sequential excitation with an AC-current and a pair of sense coils respectively mounted inside each associated field coil in an orientation to the axes of each of said field coils such that essentially no voltage is induced in said sensor coils in an environment free of a metallic object. If a metallic object comes into the vicinity of the inductive sensor four characteristic voltage value sets are produced by the sense coil pair which become subject of an algorithmic processing for defining a position and distinction criterion in respect to said hidden metallic object. The sensor arrangement has the advantage of a single point measurement resulting in an accurate position discrimination for a hidden metallic object like a rebar in concrete.

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The inductive sensor arrangement for detecting metal objects hidden in a surrounding medium comprises a pair of field coils for generating an alternating magnetic flux by a sequential excitation with an AC-current and a pair of sense coils respectively mounted inside each associated field coil in an

The inductive sensor arrangement for detecting metal objects hidden in a surrounding medium comprises a pair of field coils for generating an alternating magnetic flux by a sequential excitation with an AC-current and a pair of sense coils respectively mounted inside each associated field coil in an orientation to the axes of each of said field coils such that essentially no voltage is induced in said sensor coils in an environment free of a metallic object. If a metallic object comes into the vicinity of the inductive sensor four characteristic voltage value sets are produced by the sense coil pair which become subject of an algorithmic processing for defining a position and distinction criterion in respect to said hidden metallic object. The sensor arrangement has the advantage of a single point measurement resulting in an accurate position discrimination for a hidden metallic object like a rebar in concrete. on-inverting input, the non-inverting input receiving the electric potential at the source terminal of the second MOSFET transistor. 6. The transformer as recited in claim 1, further comprising: a storage element storing the output signal of the comparator and providing the output signal for diagnostic purposes. 7. The transformer as recited in claim 6, wherein the storage element is a microcontroller. 8. The transformer as recited in claim 1, further comprising: a capacitor in parallel between a positive input terminal and a zero potential, upstream from the first MOSFET transistor. 9. The transformer as recited in claim 1, wherein the constant-current transformer is adapted for use in cooperation with a plurality of power modules in a parallel connection. 10. The transformer as recited in claim 1, wherein the constant-current transformer is adapted for use in forming interleaved buck converters, wherein each of a plurality of power modules are driven in a phase-displaced manner. 11. A method for detecting and preventing reverse currents in a step-down constant-current transformer, the step-down constant-current transformer being used to convert an input d.c. voltage into a lower output d.c. voltage, comprising the steps of: connecting a first controllable switch including a first MOSFET transistor in series between a first input terminal and a choke; connecting a capacitor in parallel to the first input terminal and a second input terminal; connecting a second controllable switch including a second MOSFET transistor in parallel, upstream from the choke, forming a synchronous rectifier; driving the first and second MOSFET transistors with a control unit; monitoring a voltage across the second MOSFET transistor for a reverse current condition, the reverse current condition being defined by measurement of an electric potential at a center tap of a half-bridge formed by the first and second MOSFET transistors at a comparator; and blocking the second MOSFET transistor to prevent a reverse current upon the occurrence of the reverse current condition, wherein the comparator receives the center tap potential at an inverting terminal. 12. The method as recited in claim 11, wherein the control unit driving the first and second MOSFET transistors is a pulse-width control unit.