A voltage generated in a DC line at the time when a sub module is deactivated in the event of a short-circuiting fault in the DC line is suppressed. A power conversion system includes a power converter including a leg circuit, a control device, and a voltage suppression circuit connected to a DC line. The leg circuit includes a plurality of sub modules connected in series, and at least one of them is a first sub module implemented by a sub module in a full-bridge configuration or a 1.5 half-bridge configuration. When the control device detects a short-circuiting fault in the DC line, it stops a switching operation of the plurality of sub modules. The voltage suppression circuit is configured to suppress a voltage generated in the DC line when the switching operation is stopped.

A totem-pole PFC circuit is provided. The totem-pole PFC circuit includes an inductor, a first bridge arm and a second bridge arm. The first bridge arm includes a first switch and a second switch connected in series. A first middle node connected between the first and second switches is coupled to a first terminal of an AC power source through the inductor. The second bridge arm connected to the first bridge arm in parallel includes a third switch and a fourth switch connected in series. A second middle node connected between the third and fourth switches is coupled to a second terminal of the AC power source. When a polarity of the AC power source is changed, a change time of a voltage on the second middle node is longer than a preset time not less than 20 μs.

System and method for controlling turning on a first transistor and turning off a second transistor. For example, a system for controlling turning on a first transistor and turning off a second transistor includes: a logic signal generator configured to: process information associated with a first voltage related to a second voltage of a first auxiliary winding, the first auxiliary winding being coupled to a primary winding, a secondary winding, and a second auxiliary winding; generate a third voltage based on at least information associated with the first voltage, the third voltage indicating a first voltage difference from a drain terminal to a source terminal of a first transistor related to the primary winding; process information associated with the third voltage and a reference voltage; and change a logic signal from a first logic level to a second logic level.

A power supply circuit and a field emission electron source are provided. The power supply circuit includes: field effect transistors S.sub.i coupled in series via drains and sources in sequence, wherein 1≤i≤n, n≥2, and wherein a source of S.sub.1 is coupled to a negative electrode of a voltage source, and a drain of S.sub.n is used as an output terminal of the power supply circuit to couple to a load; a first group of diodes D.sub.1i coupled in series; a first group of resistors R.sub.1j, 2≤j≤n; and a current feedback module configured to adjust an internal resistance of the field effect transistors S.sub.i, coupled in series in sequence, so as to cause a current passing through the load to be constant; wherein the field effect transistors S.sub.i, 1≤i≤n, operate in a constant current region.

An on-board charger is provided with a bulk capacitor adapted to couple to a vehicle traction battery and a relay for receiving electrical power from an external power supply and to pre-charge the bulk capacitor. A power factor correction (PFC) circuit is connected between the bulk capacitor and the relay. The PFC circuit includes a switch that is adjustable between an on-position and an off-position. The switch enables current flow from the relay to the bulk capacitor in the off-position. A snubber circuit is coupled to the switch to damp a transient voltage present at the switch during a transition from the on-position to the off-position. A processor is programmed to control the switch.

An embodiment solar cell system includes a first photovoltaic (PV) module and a second PV module connected in series with each other, a differential power processing (DPP) converter configured to convert electricity generated by the first PV module and the second PV module, using a magnetic material having a multi-winding structure, and to provide the converted electricity to a battery, and a control signal generator configured to generate a control signal that controls a main switch for controlling an input-side current path and an output-side current path of the DPP converter, and to adjust a pulse width of the control signal such that a magnetizing current of the DPP converter becomes substantially zero.

An electronic circuit breaker comprising: an input connected to an electric DC power supply; an output connected to a load; the input connected to the output via a switch, said switch is controlled via a switch control line between an “ON”-state and an “OFF”-state; a switch driver connected to the switch control line, said switch driver configured to control the switch; and a switch protection, a voltage detection branch configured to output a first electric potential indicative of the electrical potential difference between the input and the output; a comparator circuit configured to compare the first electrical potential with a first threshold voltage, said first threshold voltage is indicative of an over-current level flowing through the switch; and a gate controller connected to the switch disable line and configured to disable the switch by connecting the switch control line to a potential which causes the switch to enter the “OFF”-state.

A circuit arrangement for a current converter has a half bridge with two series-connected power semiconductor switches in each case. The half bridge has a module with a power semiconductor switch in each case, a first DC voltage terminal, a second DC voltage terminal and an AC voltage terminal. A capacitor is connected in parallel with the half bridge and has a first and second capacitor terminals. A first busbar connects the first DC voltage terminal to the first capacitor terminal, and a second busbar connects the second DC voltage terminal to the second capacitor terminal. The first and the second busbars are arranged as to be spatially parallel and electrically insulated from each other. The circuit arrangement has a resistor connected in series with the capacitor, wherein the resistor is arranged in the first and/or second busbar.

An object of the present disclosure is to provide a semiconductor device capable of confirming withstand voltage of a snubber circuit after providing the snubber circuit and a method of manufacturing the semiconductor device. A semiconductor device according to the present disclosure includes: an insulating substrate; a circuit patterns provided on the insulating substrate; a snubber circuit substrate provided on the insulating substrate separately from the circuit patterns; a resistance provided on one of the circuit patterns and the snubber circuit substrate; a capacitor provided on another one of the circuit patterns and the snubber circuit substrate; and at least one semiconductor element electrically connected to the resistance and the capacitor.

An isolated converter includes an input circuit, a transformer, a first switch, a second switch and a snubber circuit. The input circuit includes at least two input capacitors, and is configured to provide an input voltage. A divider node is arranged between the at least two input capacitors. The transformer includes a primary winding and a secondary winding to generate an output voltage on the secondary winding according to the input voltage. The primary winding of the transformer is electrically connected between the first switch and the second switch. The snubber circuit is electrically connected between the first switch and the second switch, and forms a discharge path with the primary winding. The snubber circuit is configured to receive a reflected voltage from the secondary winding back to the primary winding, and the divider node is connected to the discharge path.