An order may be received for an apparatus such as a power converter or other power device, where the apparatus may be housed in a packing box. A configuration device may be programmed with information responsive to details of the order and an ID associated with the apparatus. A label or other identifying object may be created or configured (e.g., printed) and attached to the apparatus or may otherwise accompany the apparatus prior to dispatch of the packing box. The label may provide details of operating parameters of the apparatus responsive to the details of the order. Upon receipt and unpacking of the packing box, the configuration device may be connected to the apparatus, thereby to causing the apparatus to become configured.

A welding-type power supply includes a controller, a preregulator, a preregulator bus, and an output converter. The controller has a preregulator control output and an output converter control output. The preregulator receives a range of inputs voltages as a power input, and receives the preregulator control output as a control input, and provides a preregulator power output signal. The preregulator includes a plurality of stacked boost circuits. The preregulator bus receives the preregulator output signal. The output converter receives the preregulator bus as a power signal and receives the output converter control output as a control input. The output converter provides a welding type power output, and includes at least one stacked inverter circuit.

An order may be received for an apparatus such as a power converter or other power device, where the apparatus may be housed in a packing box. A configuration device may be programmed with information responsive to details of the order and an ID associated with the apparatus. A label or other identifying object may be created or configured (e.g., printed) and attached to the apparatus or may otherwise accompany the apparatus prior to dispatch of the packing box. The label may provide details of operating parameters of the apparatus responsive to the details of the order. Upon receipt and unpacking of the packing box, the configuration device may be connected to the apparatus, thereby to causing the apparatus to become configured.

A wireless power transmission apparatus including a power transmission coil that transmits electric power; a power transmission-side resonant capacitor that is connected to the power transmission coil and that, with the power transmission coil, forms a power transmission-side resonance circuit; and a self-oscillation circuit that converts a DC voltage to an AC voltage, and that supplies the AC voltage to the power transmission coil. The wireless power transmission apparatus has a state, during power transmission, in which multiple resonance points exist in a combined resonance circuit formed by magnetic coupling of the power transmission-side resonance circuit with a power reception-side resonance circuit formed from a power reception coil and a power reception-side resonant capacitor. In the state, the self-oscillation circuit operates at the lowest frequency among the multiple resonance points.

A multi-input voltage converter includes an output circuit, a first conversion circuit, and a second conversion circuit. The first conversion circuit includes a first voltage receiving module, a first transformer, a first switch. The second conversion circuit includes a second voltage receiving module, a second switch. When the second voltage receiving module receives the second input voltage, the second switch is turned on to operate, and the output circuit outputs the output voltage.

Methods and systems for balancing output currents of parallel connected resonant converters are disclosed. One such method includes matching switching frequencies for a pair of resonant converters. The method also includes carrying AC output currents of resonant tanks of each of the resonant converters through a current controlled voltage source that is coupled to each of the resonant converters of the pair of resonant converters at an AC side of each of the resonant converters of the pair of resonant converters. The method further includes inducing, for the pair of resonant converters, a voltage that is proportional to a difference in the AC currents carried through the current controlled voltage source by passing the AC currents through the current controlled voltage source. The induced voltage is oriented to oppose the greater of the AC currents and to increase the smaller of the AC currents.

A welding-type power supply includes a controller, a preregulator, a preregulator bus, and an output converter. The controller has a preregulator control output and an output converter control output. The preregulator receives a range of inputs voltages as a power input, and receives the preregulator control output as a control input, and provides a preregulator power output signal. The preregulator includes a plurality of stacked boost circuits. The preregulator bus receives the preregulator output signal. The output converter receives the preregulator bus as a power signal and receives the output converter control output as a control input. The output converter provides a welding type power output, and includes at least one stacked inverter circuit.

A switched-mode power supply with near valley switching includes a quasi-resonant converter. The converter includes a switch element that is turned on not only at the valley, but also in a window range of t.sub.NVW close to the valley, where the voltage across the switch element is at its minimum. This advantageously reduces switching loss and maintains a balance between efficiency and frequency variation.

A switched-mode power supply with near valley switching includes a quasi-resonant converter. The converter includes a switch element that is turned on not only at the valley, but also in a window range of t.sub.NVW close to the valley, where the voltage across the switch element is at its minimum. This advantageously reduces switching loss and maintains a balance between efficiency and frequency variation.

An apparatus includes an isolated power converter having an input connected to an input dc power source, a first output and a second output, and a non-isolated power converter having an input connected to the second output of the isolated power converter, wherein the first output of the isolated power converter and an output of the non-isolated power converter are connected in series.