A power converting device, in one possible configuration, includes a chopper circuit with a first semiconductor switching device, a fast recovery diode, and an inductor of which one end is connected to a connection point connecting between the first semiconductor switching device and fast recovery diode; a series circuit, connected in parallel with the fast recovery diode, including a rectifying diode with a greater reverse recovery loss and a smaller forward voltage drop than those of the fast recovery diode, and a second semiconductor switching device. The second semiconductor switching device has a lower breakdown voltage and a smaller forward voltage drop than those of the first semiconductor switching device, is configured to turn on when the first semiconductor switching device is turned off, and is configured to turn off at a timing before the first semiconductor switching device shifts from an off-state to an on-state.

A power converting device, in one possible configuration, includes a chopper circuit with a first semiconductor switching device, a fast recovery diode, and an inductor of which one end is connected to a connection point connecting between the first semiconductor switching device and fast recovery diode; a series circuit, connected in parallel with the fast recovery diode, including a rectifying diode with a greater reverse recovery loss and a smaller forward voltage drop than those of the fast recovery diode, and a second semiconductor switching device. The second semiconductor switching device has a lower breakdown voltage and a smaller forward voltage drop than those of the first semiconductor switching device, is configured to turn on when the first semiconductor switching device is turned off, and is configured to turn off at a timing before the first semiconductor switching device shifts from an off-state to an on-state.

A voltage supply circuit that generates a voltage on a voltage supply node. The voltage supply circuit includes an adjustable capacitor, an alternating voltage source, a charge source, and an adjusting circuit. When the alternating voltage on the second capacitor terminal transitions low, the voltage on the first capacitor terminal also becomes low, and the charge source provides charge to the first capacitor terminal of the adjustable capacitor. When the alternating voltage on the second capacitor terminal transitions high, the voltage on the first capacitor terminal also becomes high, and charge is thereby pumped from the first capacitor terminal to the voltage supply node. The adjusting circuit periodically samples the voltage on the voltage supply node, and adjusts the capacitance of the adjustable capacitor to increase or decrease that voltage.

A static transfer switch is provided for supplying power to a load alternately from two different power sources. Preferably, switching between the two power sources occurs within one electrical cycle. In order to control inrush currents and reduce disruption during power transfers between the two power sources, switches are provided to configure which input phases are connected to the output phases.

A static transfer switch is provided for supplying power to a load alternately from two different power sources. Preferably, switching between the two power sources occurs within one electrical cycle. In order to control inrush currents and reduce disruption during power transfers between the two power sources, switches are provided to configure which input phases are connected to the output phases.

A chopper device includes: a series circuit connecting at one end to a positive pole of a DC power source and having a breaker and a reactor; a series circuit connected between another end of the stated series circuit and a negative pole of the DC power source and having switches; a series circuit connected in parallel to the switch and having a diode and a capacitor; and a series circuit connected in parallel to the switch and having a diode and a capacitor. The chopper device outputs a DC voltage at three potentials from both ends and a midpoint of a series circuit having the capacitors by turning the switches ON/OFF. The chopper device further includes other switches connected in parallel to the switches. When a short-circuit fault is presumed to have occurred in the switch, the other switch is turned ON before interruption is performed by the breaker.

A chopper device includes: a series circuit connecting at one end to a positive pole of a DC power source and having a breaker and a reactor; a series circuit connected between another end of the stated series circuit and a negative pole of the DC power source and having switches; a series circuit connected in parallel to the switch and having a diode and a capacitor; and a series circuit connected in parallel to the switch and having a diode and a capacitor. The chopper device outputs a DC voltage at three potentials from both ends and a midpoint of a series circuit having the capacitors by turning the switches ON/OFF. The chopper device further includes other switches connected in parallel to the switches. When a short-circuit fault is presumed to have occurred in the switch, the other switch is turned ON before interruption is performed by the breaker.

A high-side pre-driver includes a first high-side transistor and a second high-side transistor, a low-side pre-driver includes a third high-side transistor and a fourth high-side transistor and a delay is provided in at least one of a time period between a first gate signal configured to turn on the first high-side transistor and a second gate signal configured to turn on the second high-side transistor and a time period between a third gate signal configured to turn on the third high-side transistor and a fourth gate signal configured to turn on the fourth high-side transistor.

A voltage supply circuit that generates a voltage on a voltage supply node. The voltage supply circuit includes an adjustable capacitor, an alternating voltage source, a charge source, and an adjusting circuit. When the alternating voltage on the second capacitor terminal transitions low, the voltage on the first capacitor terminal also becomes low, and the charge source provides charge to the first capacitor terminal of the adjustable capacitor. When the alternating voltage on the second capacitor terminal transitions high, the voltage on the first capacitor terminal also becomes high, and charge is thereby pumped from the first capacitor terminal to the voltage supply node. The adjusting circuit periodically samples the voltage on the voltage supply node, and adjusts the capacitance of the adjustable capacitor to increase or decrease that voltage.

A voltage supply circuit that generates a voltage on a voltage supply node. The voltage supply circuit includes an adjustable capacitor, an alternating voltage source, a charge source, and an adjusting circuit. When the alternating voltage on the second capacitor terminal transitions low, the voltage on the first capacitor terminal also becomes low, and the charge source provides charge to the first capacitor terminal of the adjustable capacitor. When the alternating voltage on the second capacitor terminal transitions high, the voltage on the first capacitor terminal also becomes high, and charge is thereby pumped from the first capacitor terminal to the voltage supply node. The adjusting circuit periodically samples the voltage on the voltage supply node, and adjusts the capacitance of the adjustable capacitor to increase or decrease that voltage.