A dual-input power conversion system includes a first primary side power network comprising a first hold-up capacitor, wherein the first primary side power network has inputs configured to be coupled to a first power source, and outputs coupled to a transformer, a second primary side power network comprising a second hold-up capacitor, wherein the second primary side power network has inputs configured to be coupled to a second power source, and outputs coupled to the transformer, and a secondary side power network having inputs coupled to a secondary side of the transformer, and outputs coupled to a load, wherein the first primary side power network and the second primary side power network are configured such that a voltage across one of the first hold-up capacitor and the second hold-up capacitor is maintained by a voltage reflected from the secondary side to a corresponding primary side.

A flyback converter and forward converter is described that include an input coil, a primary switch connected in series with the input coil, and an output coil magnetically coupled to the input coil. The input coil has an input side connected to an input of the circuit and a switch side connected to the primary switch. The converter further includes an input side clamp circuit, the input side clamp circuit including an energy store and a switch arrangement controlled such that the leakage inductance energy stored, in use, in the energy store, can be discharged to the input side of the input coil.

A method involves controlling, for a duration of a first modulation period, a first average off-time of a main switch of a power converter such that the first average off-time of the main switch corresponds to a first intermediate valley number of multiple intermediate valley numbers, an average of the intermediate valley numbers corresponding to a target number of valleys of a resonant waveform at a drain node of the main switch. A second intermediate valley number of the intermediate valley numbers is selected upon expiration of the first modulation period. A difference of the second intermediate valley number and the first intermediate valley number is equal to a fractional valley number offset. A second average off-time of the main switch is controlled for a duration of a second modulation period such that the second average off-time of the main switch corresponds to the second intermediate valley number.

A power conversion device includes first and second current detectors. A coil is connected a first power terminal through the first and second current detectors. A first switch has a source terminal connected to the coil and a second semiconductor switch has a drain terminal connected to the coil. A first diode is connected between a drain terminal of the first semiconductor switch and a second power supply terminal. A second diode is connected between a source terminal of the second semiconductor switch and the second power terminal. A capacitor is connected in parallel with the first and second diodes. A control circuit is configured to turn the first and second semiconductor switches on or off based on current detections of the first and second current detectors.

A power stage controller includes: a reference circuit having a first reference input and a reference output, the first reference input adapted to be coupled to an input terminal of a power stage, and the reference circuit configured to adjust a reference voltage at the reference output responsive to whether a voltage at the first reference input is below a threshold; and a comparator having a current sense input, a second reference input, and a comparator output, the current sense input adapted to be coupled to a current terminal of the power stage, the second reference input coupled to the reference output, and the comparator output coupled to a driver input of a driver circuit configured to configured to control a driver output adapted to be coupled to a gate of a transistor of the power stage and responsive to the driver input.

An isolated switched-mode power converter converts power from an input source into power for an output load. Power switches within a primary-side power stage control the amount of power input to the power converter and, ultimately, provided to the output load. A digital controller on the secondary side of the power converter generates signals to control the power switches. This controller also senses a rectified voltage on the secondary side of the power converter and uses this sensed voltage to detect fault conditions of the primary side. For example, the sensed rectified voltage is used to detect undervoltage or overvoltage conditions of the input power source of the power converter, or faulty power switches within the primary-side power stage.

A resonant converter and a manufacturing method of a transformer thereof are provided. The resonant converter includes a full bridge circuit, an element, a first branch circuit, a second branch circuit and a secondary winding. The full bridge circuit includes a first node and a second node. The element includes an inductor or a capacitor. The first branch circuit includes a first primary winding. The second branch circuit includes a second primary winding, and the first and second primary windings have the same turn number. The transformer is constructed by the first and second primary windings and the secondary winding. The first branch circuit, the element and the second branch circuit are sequentially coupled in series between the first and second nodes. The first branch circuit and the second branch circuit are symmetrically located with respect to the element. The first and second branch circuits have the same impedance.

The invention relates to enhanced adjusting of the control variables for a DC-DC converter comprising multiple DC-DC converter modules (30-1, 30-2). For this purpose, alongside the conventional controlling of the individual DC-DC converter modules, an additional correction variable (K-1, K-2) is determined which can be added to the control variable (R4-1, R4-2). In particular, the correction variable can take into account individual properties of the DC-DC converter modules, such as component tolerances or similar. For this purpose, correction values suitable for the individual DC-DC converter modules can be determined in advance and stored in a non-volatile storage means. Using these previously stored links, the control variables for the individual DC-DC converter modules can be individually adjusted.

A lighting system includes two or more lighting fixtures, each comprising a housing, at least one light source mechanically supported by the housing, at least one pipe thermally coupled to the housing to carry a fluid coolant, an AC power port, and at least one network communications port. The AC power ports of respective lighting fixtures are coupled together with a plurality of industrial power cables without using one or more conduits for the plurality of industrial power cables. The network communications ports of the respective lighting fixtures are coupled together with a plurality of waterproof network communications cables. In one example, a lighting system kit comprises two or more lighting fixtures having an AC power port comprising an industrial type connector. The kit further comprises multiple industrial power cables and one or more industrial drop tee cables.

Systems and methods for providing a constant current controller for use in constant current welding applications are described. In one embodiment, a current controller controls the output current of the welding torch without directly measuring the output current of the welding torch. The current controller controls or sets a current in a primary winding of a transformer in an inverter of a welding power supply to control the output current of the welding torch.