Constant-power supply for low impedance loads including a transformer with primary and secondary windings and a magnetic shunt for diverting magnetic flux associated with the windings

摘要

Disclosed is a constant-power supply apparatus (1) for low impedance loads. The apparatus (1) includes a transformer having a primary winding (3) and a secondary winding (4). Magnetic flux generated by a varying primary voltage applied to the primary winding (3) induces a varying secondary voltage on the secondary winding (4). The apparatus (1) also includes a torroidal transformer core (2) over which the primary winding (3) and secondary winding (4) are applied, wherein at least a portion of the secondary winding (4) is spatially separated from the primary winding (3). At least one magnetic shunt (5) is arranged to provide a diversion path for magnetic flux generated by the primary winding (3), which diverts magnetic flux from the secondary winding (4). A control coil is provided in association with the magnetic shunt (5), the control coil being adapted to dynamically modify the reluctance of the magnetic shunt (5) and thereby dynamically modifying the maximum output current capable of being delivered by the power supply (1).