An arrangement for transferring information between the secondary and primary circuit of a transformer wherein control information is transferred to the primary circuit of a power transformer by means of auxiliary windings in the same transformer. The auxiliary windings are arranged in pairs in the transformer core branches in such a manner that the magnetic fluxes (.PHI..sub.c) do not induce a voltage in the energy-transferring windings (pw1, pw2), and the voltages induced in the auxiliary windings by the magnetic flux (.PHI..sub.p) corresponding to the energy transfer are opposite both in the primary-side winding pair (cw1a, cw1b) and in the secondary-side winding pair (cw2a, cw2b). Thus the transfer of a control signal and the transfer of energy will not disturb one another. The transformer may be implemented as a planar structure on a printed circuit board.

A pulsewidth modulated DC to DC converter is disclosed which includes an inductor having first and second windings. A transformer having a plurality of primary windings is selectively coupled across a DC source through first and/or second inductor windings by a plurality of switching devices. The first and second inductor windings provide a low current through first and third paths in first and third transformer windings during first and third periods of a cycle. The first inductor winding provides a high current through second and fourth paths in second and fourth transformer windings during second and fourth periods of a cycle, respectively.

An integrated magnetic assembly for use in the direct current output circuit of a high frequency electronic switching power supply, comprising magnetic core sections for the output transformer and inductor windings and a common magnetic core segment completing the magnetic flux paths for the transformer and inductor windings. An auxiliary winding on one or both of the core sections is supplied with energy from the capacitor of a snubber circuit connected across the primary side of the magnetic output circuit. This auxiliary winding is magnetically coupled to the secondary side of the magnetic circuit to transfer energy to the power supply output during a portion of the switched current cycle.

DC-to-dc switching converters that deliver non-pulsating output current use a conventional transformer and a flyback transformer with primary windings recurrently connected in series to the primary d-c energy source and with secondary windings alternately connected to the output load.

The present invention provides a resonant power converter for changing the magnitude of a DC voltage. The converter includes a common magnetic core with three legs (an "EE" core). The core has primary and secondary windings wound onto a first outside leg, and a tank winding and control windings wound onto a second outside leg. Control switch means are provided for effecting alternate pulses of current flow through the primary winding to effectuate alternate flux flow, the control switch means and the primary winding having a predetermined parasitic capacitance with a predetermined delay time between the termination of a given pulse and initiation of the succeeding pulse. The secondary windings are oriented to conduct alternately in phase with the alternate flux flow, there being inherent in the first leg of the transformer a magnetizing inductance, such that the magnetizing current will be great enough to charge said parasitic capacitance in a controlled fashion.