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A constant voltage inductive power coupling for magnetically transferring electrical power from a power source through an air gap to a load comprising a first electromagnetic inductor connected to a power source to generate a shaped alternating magnetic field, a said inductor with a saturable core s

A constant voltage inductive power coupling for magnetically transferring electrical power from a power source through an air gap to a load comprising a first electromagnetic inductor connected to a power source to generate a shaped alternating magnetic field, a said inductor with a saturable core separated by an air gap from the first inductor and magnetically coupled thereto to receive the shaped magnetic field, the core being responsive to the field to enter a state of magnetic saturation. A coil is electromagnetically coupled to the saturable core and has output leads connected to the load. A capacitor is in electrical communication with the coil to form a tuned circuit that is below resonance at the coupling operating frequency. The magnetic field induced by the first inductor to the second inductor causes voltage in the coil, whose magnitude is determined by the amount of magnetic flux in the core. The saturable core is responsive to any change in input voltage to magnetically counteract such change so as to maintain the core in its state of saturation thereby tending to keep the output voltage constant. Also any increase in load current is associated with a closer approach of the tuned circuit to a resonant condition tending to maintain the output voltage at a constant level. The invention is particularly useful in battery charging circuits or for other applications where the voltage required must be kept at a constant level.

대표청구항 ▼

A constant voltage inductive power coupling for magnetically transferring electrical power from a power source through an air gap to a load, the coupling comprising: electromagnetic means with substantial leakage reactance, responsive to the power source to generate a shaped alternating magnetic fie

A constant voltage inductive power coupling for magnetically transferring electrical power from a power source through an air gap to a load, the coupling comprising: electromagnetic means with substantial leakage reactance, responsive to the power source to generate a shaped alternating magnetic field; a saturable core in spaced-apart relationship to the electromagnetic means to define an air gap there between and magnetically coupled thereto to receive mutual flux of the shaped magnetic field, the core having enlarged poles and a region of reduced cross sectional area such that the region is in a state of magnetic saturation when the amount of magnetic flux that is required to induce the desired constant output voltage is present in the core, thereby tending to limit the output voltage to the desired constant voltage and counteracting any excess electromagnetic force in the electromagnetic means by causing leakage flux from the electromagnetic means; a coil, electromagnetically coupled to the core whereby the magnetic field induces voltage in the coil, the voltage determined by the amount of magnetic mutal flux in the core, said saturable core also providing an inductive component of leakage flux which varies in response to any change in input voltage to said electromagnetic means to magnetically counteract an associated change in said field so as to maintain the core in its state of saturation thereby tending to keep the output voltage from said coil constant; and a capacitor in electrical communication with said coil to form therewith a tuned circuit that is below resonance at operating frequency when said core is in its saturated state, any increase in output current being associated with a closer approach of the circuit to a resonant condition and thereby tending to maintain the output voltage at a constant level.