A rectifier has a d.c. return terminal and two d.c. output terminals. The elements of the rectifier are connected so that d.c. currents through the output terminals are discontinuous and that the sum of these currents is continuous d.c. output. Switches are provided to connect the d.c. output terminals to a common supply terminal for a load, or to isolate the output termnals from each other and from the load.

A symmetrical ac power system provides a balanced ac output, whose maximum voltage with respect to a reference ground potential is one-half the ac output voltage, and which is derived from a single phase ac source through the use of an isolation transformer having a center-tapped secondary winding. The center tap is connected to the output power load circuit as a ground reference potential with respect to the symmetrical ac output so as to constitute the reference ground potential for the power supply and load. Since symmetrical ac power is applied to the load by the system, reactive load currents, other power artifacts, EMI and RFI emissions and other interference and noise components ordinarily resulting from the application of conventional ac power to the load are reduced or eliminated by appearing as equal inversely phased signal elements which cancel one another. In order to maximize the performance of the symmetrical power system, the isolation transformer has a bifilar-wound secondary winding.

A converter circuit includes a magnetic core, a primary winding, a secondary winding, a main rectification circuit, and an auxiliary rectification circuit. The primary winding and the secondary winding are wound around the magnetic core. The main rectification circuit and the auxiliary rectification circuit are both connected to the secondary winding and produce output voltages having different magnitudes. The auxiliary voltage powers the control and drive circuits for both the primary switches and the synchronous rectifiers used for the main rectification circuit.

An energy-feedback clamping circuit of a power converter is proposed. The converter includes a transformer coupled to a full-wave rectifier circuit. The clamping circuit includes: two clamping diodes having two anodes coupled to each other at a common-anode terminal and two cathodes coupled to two terminals of a secondary winding of the transformer, a first clamping capacitor having a first terminal coupled to a cathode of a first rectifying diode of the rectifier circuit and a second terminal coupled to the common-anode terminal, a second clamping capacitor having a first terminal coupled to a connecting node of the output filtering inductor and capacitor of the rectifier circuit and a second terminal coupled to the common-anode terminal, and a converter circuit having an input terminal coupled to the second clamping capacitor and an output terminal for offering a power source.

A d.c. power supply for computer logic circuits which is sensitive to brief interruptions in a.c. source power. The power supply includes an input transformer providing first and second a.c. voltages which are rectified to first and second d.c. voltage, the second d.c. voltage being of greater magnitude than the first d.c. voltage. A linear voltage regulator receives the first d.c. voltage as normal input and provides a third d.c. voltage of lesser magnitude than the first d.c. voltage. A storage capacitor is charged by the second d.c. voltage. A differential amplifier detects an interruption in source power and causes the storage capacitor to be connected to the input of the regulator whereby the regulator output is maintained during a brief interruption in source power by the discharge current of the storage capacitor.