A rectifier according to an aspect of the present disclosure includes: a bridge circuit that derives a positive voltage component and a negative voltage component from an AC power supply voltage; a smoothing capacitor that smooths an output voltage from the bridge circuit; a pre-charge resistor that is provided between the bridge circuit and the smoothing capacitor, and reduces an inrush current; a charge switch that is provided in parallel with the pre-charge resistor; and a controller that controls the charge switch between an open state and a close state, wherein when application of the AC power supply voltage to the bridge circuit is started, the controller closes the charge switch if a voltage applied between ends of the pre-charge resistor is determined to become equal to or lower than a predetermined resistor threshold voltage.

A rectifier according to an aspect of the present disclosure includes: a bridge circuit that derives a positive voltage component and a negative voltage component from an AC power supply voltage; a smoothing capacitor that smooths an output voltage from the bridge circuit; a pre-charge resistor that is provided between the bridge circuit and the smoothing capacitor, and reduces an inrush current; a charge switch that is provided in parallel with the pre-charge resistor; and a controller that controls the charge switch between an open state and a close state, wherein when application of the AC power supply voltage to the bridge circuit is started, the controller closes the charge switch if a voltage applied between ends of the pre-charge resistor is determined to become equal to or lower than a predetermined resistor threshold voltage.

Provided are a power reception device and a power reception control method capable of suppressing the application of an excessive voltage even in the case where a time lag occurs before power transmission by a power transmission device is stopped after disconnection between the power reception device and a load. A power reception device includes: a power reception coil that receives power transmitted from a power transmission coil; a rectification circuit that rectifies alternating current power received by the power reception coil; and a control circuit that is connected between the rectification circuit and a load to which direct current power outputted from the rectification circuit is supplied, and controls that the direct current flowing through the load to be constant or equal to or less than a predetermined value by the direct current power.

Provided are a power reception device and a power reception control method capable of suppressing the application of an excessive voltage even in the case where a time lag occurs before power transmission by a power transmission device is stopped after disconnection between the power reception device and a load. A power reception device includes: a power reception coil that receives power transmitted from a power transmission coil; a rectification circuit that rectifies alternating current power received by the power reception coil; and a control circuit that is connected between the rectification circuit and a load to which direct current power outputted from the rectification circuit is supplied, and controls that the direct current flowing through the load to be constant or equal to or less than a predetermined value by the direct current power.

A load control system includes a switch, a controller, an additional functioning unit, a power source, and an adjuster. The controller is configured to switch the switch between a conduction state and a non-conduction state. The switch is electrically connected in series to a load with respect to an alternating-current power source. The additional functioning unit is configured to perform a process different from switching operation of the switch. The power source receives electric power supplied from the alternating-current power source to generate electric power to be supplied to the controller and the additional functioning unit. The adjuster adjusts a supply time period during which the power source is supplied with electric power from the alternating-current power source in a maximum load state of a state where the additional functioning unit normally operates, electric power consumption by the additional functioning unit being maximum in the maximum load state.

A power converting apparatus includes: a boost circuit including a reactor supplied with first voltage output from an alternating-current power supply, a first leg including first upper-arm and lower-arm switching elements connected in series, and a second leg connected in parallel with the first leg and including second upper-arm and lower-arm switching elements connected in series, and boosting the first voltage; a first voltage detecting unit detecting the first voltage; a smoothing capacitor smoothing voltage output from the boost circuit; and a second voltage detecting unit detecting second voltage smoothed by the smoothing capacitor. When the second voltage is larger than the first voltage and is lower than or equal to twice the first voltage, a width of a second drive pulse to turn on the first upper-arm switching element is larger than a width of a first drive pulse to turn on the first lower-arm switching element.

A power conversion device includes a single-phase full-wave rectifying unit, an electrolytic capacitor, a plurality of chopper circuits that are arranged between the single-phase full-wave rectifying unit and the electrolytic capacitor, each of the chopper circuits including a reactor, a first MOSFET connected in parallel with the single-phase full-wave rectifying unit, and a second MOSFET connected to a positive terminal of the electrolytic capacitor at one end and to the reactor and the first MOSFET at the other end, a first current detecting unit to bidirectionally detect a current flowing through the reactor, and a control unit to control an operation of the first MOSFET by using the detection result from the first current detecting unit.

Also disclosed is a method for exciting a generator of a direct current power supply with a controller. The method includes receiving a phase voltages associated with multiphase output of the generator. The method includes determining a maximum line-to-line voltage based on the phase voltages. The method includes operating an exciter winding driver with an oscillating signal generated according to the maximum line-to-line voltage.

Also disclosed is a method for exciting a generator of a direct current power supply with a controller. The method includes receiving a phase voltages associated with multiphase output of the generator. The method includes determining a maximum line-to-line voltage based on the phase voltages. The method includes operating an exciter winding driver with an oscillating signal generated according to the maximum line-to-line voltage.

An audio driver circuit includes a modulator circuit configured to receive an audio input signal and produce a first modulated digital pulse signal. The first modulated digital pulse signal has a magnitude that switches between a supply power voltage and a supply ground voltage. The audio driver circuit also includes a switched driver circuit coupled to the modulator circuit to receive the first modulated digital pulse signal and configured to provide a second modulated digital pulse signal for driving an MOS (metal oxide semiconductor) output transistor. The second modulated digital pulse signal has a same timing pattern as the first modulated digital pulse signal and has a magnitude that tracks linearly with the magnitude of the audio input signal.