Abstract: A power-factor corrected AC/DC converter has three half-bridge legs, electrically coupled with each other in parallel, each leg having a pair of switches. Each switch of the pair is electrically coupled to the other in series via a respective node that is electrically coupled through an inductor to an AC line. The converter has a fourth half-bridge leg electrically coupled with the other legs to form an electrically parallel circuit. The fourth leg has a pair of switches electrically coupled to each other in series via a fourth node, which is selectively electrically coupleable to a neutral or a second AC line. The converter has a controller that operates the three legs as a 3-channel interleaved AC/DC boost converter and couples the fourth node to the neutral or second AC line if the input is single-phase, and as a 3-phase AC/DC boost converter if the input is three-phase.

Abstract: A single-stage AC/DC converter includes a boost PFC AC/DC converter and a half-bridge split-capacitor DC/DC converter. The boost PFC AC/DC converter includes a boost inductor, and the half-bridge split-capacitor DC/DC converter includes an inductor in series with a primary winding of a transformer. A method of operation of a single-stage AC/DC converter that includes a boost PFC AC/DC converter and a half-bridge split-capacitor DC/DC converter includes modulating a switching frequency of at least one switch. The method may further include maintaining a constant duty cycle, for example a duty cycle of 0.5. An implementation of the boost inductor in a boost PFC AC/DC converter of a single-stage AC/DC converter includes a variable boost inductor, such as two inductors of approximately equal inductance, and a boost inductor switching circuit, such as two single-pole, double-throw relays.

Abstract: Methods and apparatus for zero current detection and discontinuous conduction mode digital detection for a boost power factor correction converter based on a digital signal processor are disclosed. By effectively using resources in a processor with integrated high-speed comparators, simple detection can be accomplished with cost and performance over alternative detection methods. The methods and apparatus can be employed in an adaptive digital controller for mixed-conduction mode in the converter and can provide for lower total harmonic distortion and greater power factors than a non-adaptive controller.

Abstract: A method and apparatus for circuit conditioning, such as for providing power factor correction, is provided, using existing or minimal additional circuitry, at minimal or no additional cost to the manufacture of the circuit. The circuit conditioning is implemented by controlling an output side of the circuit based on a value sensed on the output side of the circuit and a relationship between the output side and an input side of the circuit.