A resonant half-bridge flyback power converter includes: a first transistor and a second transistor which form a half-bridge circuit; a transformer and a resonant capacitor connected in series and coupled to the half-bridge circuit; and a switching control circuit configured to generate a first driving signal and a second driving signal to control the first transistor and the second transistor respectively for switching the transformer to generate an output voltage. The first driving signal is configured to magnetize the transformer. The second driving signal includes at most one pulse between two consecutive pulses of the first driving signal. The switching control circuit generates a skipping cycle period when an output power is lower than a predetermined threshold. A resonant pulse of the second driving signal is skipped during the skipping cycle period. The skipping cycle period is increased in response to the decrease of the output power.

A redundant power supply apparatus includes at least two power inlets, at least two power supply units, and a common component. Each power inlet is connected to an AC power source. Each power supply unit has an input side and the at least two power supply units having a common output side, each input side is connected to the power inlet, and each power supply unit is configured to convert the AC power source into a DC power source. The common component is connected at the common output side and configured to receive DC power sources. Accordingly, the redundant power supply apparatus is provided to improve reliability of redundant operations between multiple external power sources without using mechanical switches.

Power module includes transformer unit including primary and secondary windings and magnetic core; first and second capacitor units coupled to first terminal of primary winding of transformer unit through first node; first and second external pins respectively coupled to first terminal of first capacitor unit and second terminal of second capacitor unit; first and second switch units coupled to second terminal of primary winding of transformer unit thorough second node; third and fourth external pins respectively coupled to first terminal of first switch unit and second terminal of second switch unit; secondary-side circuit coupled to secondary winding; and fifth and sixth external pins electrically coupled to first and second output terminals of secondary-side circuit, respectively. First external pin is coupled to one of third and fourth external pins selectively.

The invention provides a driver circuit for driving an LED arrangement which uses a switch mode power converter, for example a flyback ringing choke converter, which comprises a main switch (e.g. bipolar transistor) and a sub-circuit for generating a current for the control terminal of the main switch. The sub-circuit in some examples makes use of an auxiliary winding as a voltage supply, and further comprises a ramp circuit for generating a ramp voltage from the voltage supply and a voltage follower, such as a control transistor, connected between the voltage supply and the control input of the main switch. By ramping up the current of the main switch, the losses arising as a result of the current flowing to the control input of the main switch are reduced. One set of examples makes use of a flyback ringing choke converter, which enables low cost implementation and good efficiency. The driver is able to receive a wide range of input voltages, by ensuring that the power loss is kept low. In particular, by ramping up the control current of the main switch, the losses arising as a result of the current flowing are reduced.

A dual-pulse MIG welding power source based on SiC power devices may include a main circuit and a digital control circuit. The main circuit may include a power frequency rectifier filter module, a first SiC high frequency inverter module, a first high frequency transformer, and a first SiC fast full-wave rectifier filter module connected sequentially. The power frequency rectifier filter module may be connected to a three-phase AC power supply, and the first SiC fast full-wave rectifier filter module may be connected to a load. The digital control circuit may include a digital human-machine interaction module, a core control module, a SiC high-frequency drive module, a load voltage and current detection feedback module, and a wire feeding control module. The digital human-machine interaction module may be connected to the core control module.

Switched mode power supply (SMPS) with a control circuitry and method of operating such a SMPS are described. The control circuitry includes a first driver to drive an input switch in response to a driving signal, a pulse circuit to generate a pulse signal in response to the driving signal, a timer circuit to generate a delayed signal in response to the pulse signal and a second driver to drive to the output switch in response to the delayed signal.

A voltage regulator circuit comprises a plurality of voltage regulator phases, a first load output coupled to the plurality of voltage regulator phases for providing a first output voltage, a first coupling inductor having a first winding and a second winding, the first winding coupled in series between a first voltage regulator phase of the plurality of voltage regulator phases and the first load output, a second load output coupled to the second winding for providing a second output voltage, and a first switch coupled in series with the second winding. A method comprises detecting a startup event; determining an installed processor type; retrieving a configuration parameter value; providing a first output voltage at a first load output; providing, at a second load output coupled to the second winding, a second output voltage; and controlling a first duty cycle of a first switch coupled in series with the second winding.

A direct current (DC)-DC converter includes a transformer and a gas tube-switched inverter circuit. The transformer includes a primary winding and a secondary winding. The gas tube-switched inverter circuit includes first and second inverter load terminals and first and second inverter input terminals. The first and second inverter load terminals are coupled to the primary winding. The first and second inverter input terminals are couplable to a DC node. The gas tube-switched inverter circuit further includes a plurality of gas tube switches respectively coupled between the first and second inverter load terminals and the first and second inverter input terminals. The plurality of gas tube switches is configured to operate to generate an alternating current (AC) voltage at the primary winding.

A direct current (DC)-DC converter includes a transformer and a gas tube-switched inverter circuit. The transformer includes a primary winding and a secondary winding. The gas tube-switched inverter circuit includes first and second inverter load terminals and first and second inverter input terminals. The first and second inverter load terminals are coupled to the primary winding. The first and second inverter input terminals are couplable to a DC node. The gas tube-switched inverter circuit further includes a plurality of gas tube switches respectively coupled between the first and second inverter load terminals and the first and second inverter input terminals. The plurality of gas tube switches is configured to operate to generate an alternating current (AC) voltage at the primary winding.

A control method for an active clamp converter has steps of: detecting a state of the load; when the state of the load is a light-load state, using a skipping mode to control a switch frequency of a master switch; when the state of the load is not the light-load state, using an ACF mode to control the switch frequency of the master switch. In the skipping mode, the switch frequency is decreased when the state of the load is getting light, thus providing an energy efficiency power saving function for the light-load state. In the ACF mode, the master switch is controlled to turn on while a reverse current is generated, thus the switching loss of the master switch is reduced.