A multi-stage driver system includes a switched mode power circuit for providing power to different electrical load(s). Multi-stage driver system includes a control block including at least one microcontroller coupled to control operations of the switched mode power circuit. Switched mode power circuit includes a high voltage region, a low voltage region, and an isolation barrier. High voltage region of the switched mode power circuit includes a switched rectifier and a switched bridge circuit configured to produce a high voltage bidirectional pulse train signal for output to an isolation barrier. Low voltage region of the switched mode power circuit includes a rectification circuit coupled to the isolation barrier and at least one switched converter circuit coupled to the rectification circuit. Control block receives real-time input signals (e.g., analog voltage reading(s)) from the high and low voltage regions and responsively produces control signals to the high and low voltage regions.

An arrangement provides an AC current to a load for direct electrical heating. The arrangement includes a AC-DC-AC converter cell. The converter cell has at least two converter input terminals connected to at least two transformer output terminals. The converter cell has a first converter output terminal and a second converter output terminal, wherein the first converter cell output terminal is adapted to be connected to the load.

A resonant inductive power transfer circuit has a power converter to supply to a load, and the converter is concurrently controlled to create a controlled reactance that substantially compensates for variability in the coupling with the another resonant inductive power transfer circuit and/or changes in the load supplied by the power converter.

Disclosed is a method and a control circuit. The method includes operating a buffer circuit (1) in a first operating mode or a second operating mode. Operating the buffer circuit (1) in the first operating mode includes buffering, by a capacitor parallel circuit including a first capacitor (11) and a second capacitor (12), power (Po) provided by a power source (3) and received by a load (4). Operating the buffer circuit (1) in the second operating mode includes supplying power to the load (4) by the second capacitor (12), and regulating a first voltage (Upn) across the second capacitor (12), wherein regulating the first voltage (Upn) comprises transferring charge from the first capacitor (11) to the second capacitor (12).

According to one aspect of the present disclosure, there is provided an apparatus that includes first, second, and third power converter stages connected to a transformer module. At least one of the first, second, and third power converter stages is a multi-level power converter stage that has multiple configurations to generate different output voltages from an input voltage.

A capacitive element has its terminals coupled together by two thyristors electrically in antiparallel. The discharge of the capacitive element is controlled by the application of a gate current to one thyristor of the two thyristors which is in a reverse-biased state in response to a voltage stored across the terminals of the capacitive element. The reverse-biased thyristor responds to the applied gate current by passing a leakage current to discharge the stored voltage.

A power receiving device of a wireless power transfer system receives power from a power transmitting circuit connected to a power source and having a power transmitting coil. The power receiving device includes a power receiving circuit, a power converter, an LC filter, and switches which are controlled by a control device on the basis of voltage detected by voltage detection means for detecting output voltage of the power receiving circuit, so that conduction between the power receiving circuit and the power converter is interrupted during a non-power-transfer period.

An image display device of the present invention comprises a display and a power supply unit, and the power supply unit comprises: a first voltage detection unit that detects an input AC voltage by using a first resistance element; a second voltage detection unit that detects an input AC voltage by using a differential circuit having a capacitor element and a second resistance element; a converter that converts the level of the input voltage on the basis of a switching operation of a switching element so as to output a DC voltage; and a control unit that may control the switching element in the converter to be turned on, on the basis of a first signal detected by the first voltage detection unit or a second signal detected by the second voltage detection unit. As such, the present invention operates stably even when an AC voltage of a square wave is applied.

Embodiments of this application provide a conversion circuit and a control method thereof. The conversion circuit provided in embodiments of this application implements a function of a low-speed switch in an inverter by using the switch module, and implements a function of a high-speed switch in the inverter by using the bridge arm circuit. A circuit design is suitable and efficient, and can implement high efficiency at low costs. In addition, at least two bridge arm circuits are disposed in the circuit, which facilitates dynamic steady state current equalization and heat dispersion, and can implement high power density. In addition, the switch element in the bridge arm circuit can implement a zero voltage switch ZVS. Therefore, a loss of the conversion circuit provided in embodiments of this application is low.

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.