In one form, a capacitor voltage limiter (240), comprises a supply node (244), a pass element (242) having a first current electrode coupled to the supply node (244), a control electrode, and a second current electrode. The second current electrode is adapted to be coupled to an external storage capacitor (250). Additionally, the capacitor voltage limiter includes an amplifier having a non-inverting input for receiving a reference voltage, and an inverting input coupled to the second current electrode of the pass element (242). The amplifier includes an output coupled to the control electrode of the pass element (242). The capacitor voltage limiter also includes a rectifier (241) having an input coupled to the second current electrode of the pass element (242), and an output coupled to the first current electrode of the pass element (242).

Bootstrap circuit includes: a first transistor of first conductivity type having a first main electrode, a second main electrode and a control electrode connected to a first power supply terminal, a first node, and a second node, respectively; a second transistor of the first conductivity type having a first main electrode, a second main electrode, and a control electrode connected to the first power supply terminal, the second node and the first node, respectively; a first capacitor having a first end connected to the first node and a second end where a first boost pulse is applied; a second capacitor having a first end connected to the second node and a second end where a second boost pulse having opposite polarity to the first boost pulse is applied; and a boost output terminal which outputs boost voltage higher than first power supply voltage supplied to the first power supply terminal.

This application provides example circuit modules and example electronic devices comprising the circuit module. One example circuit module includes a power input terminal, a power output terminal, a first switching transistor, a second switching transistor, a comparison unit, a boost unit, an energy storage unit, and a direct current conversion unit, where the first switching transistor is turned on and the second switching transistor is cut off when a source voltage input by the power input terminal to the comparison unit is greater than the preset threshold, or the first switching transistor is cut off and the second switching transistor is turned on when a source voltage input by the power input terminal to the comparison unit is less than or equal to the preset threshold.

An information handling system includes a power supply and a power assist unit. The power supply powers a power rail. The power assist unit includes a power storage element, a converter including a semiconductor device coupled to provide power from the power storage element to the power rail, and a controller configured to receive a load indication that indicates a power demanded by the load and to provide an intermediate output based upon the load indication. The controller includes a boost element to receive the intermediate output and to provide a controller output. The controller output is a sum of a bias voltage level provided by the bias element and the intermediate output. The controller output is coupled to a gate terminal of the semiconductor device. The converter provides power from the power storage element to the power rail in response to the controller output.

This power supply unit of a control system outputs a notification signal to a calculation unit when a time in which an input voltage becomes smaller than a threshold voltage exceeds a prescribed first measurement time. When detecting that a predetermined second measurement time has elapsed after the notification signal has been received, the calculation unit outputs an instruction signal instructing the execution of a process before a stop in preparation for a prescribed stop of power supply, and executes the process before the stop in place of the current process. Settings of the threshold voltage and the second measurement time are configured to be changeable by means of an external operation.

A power conversion device of an embodiment includes a power conversion unit, a first capacitor, a gate circuit, a bypass circuit, and a discharging circuit. The power conversion unit includes a plurality of switching elements each having a gate and generates alternating current (AC) power from direct current (DC) power supplied to a provided DC input terminal. The first capacitor is provided on a DC input side of the power conversion unit. The gate circuit includes a drive circuit configured to output a gate drive signal to be supplied to gates of one or more switching elements among the plurality of switching elements and a second capacitor configured to smooth a power supply voltage of power to be supplied to the drive circuit. The bypass circuit causes the second capacitor to be charged with a part of power stored in the first capacitor at the time of power supply loss of a control system circuit and enables the gate drive signal to be maintained in a negative bias by power stored in the second capacitor.

A utility meter includes: a rectifier configured to rectify AC voltage from a power grid to generate a primary DC voltage supply; and a primary holdup circuitry, including: first capacitors coupled to a primary DC voltage rail and configured to store energy from the primary voltage supply; a switch coupled to the first capacitors; and a control circuit configured to control the primary holdup circuitry, wherein the control circuit is configured to: determine that a secondary DC voltage of a secondary voltage supply is approximately equal to a first specified threshold voltage; and generate a control signal to causes the switch to turn on and cause the one or more first capacitors to release a portion of the energy stored in the one or more first capacitors to the primary DC voltage rail.

A power device includes a power factor corrector, an auxiliary capacitor, a switching device, an auxiliary boost circuit, a controller and a voltage conversion device. The switching device has a first end electrically connected to the output end of the power factor corrector, and a second end electrically connected to one end of the auxiliary capacitor. An output end of the auxiliary boost circuit is electrically connected to the output end of the power factor corrector, an input end of the auxiliary boost circuit is electrically connected to a middle end of the switching device, and a ground end of the auxiliary boost circuit is electrically connected to another end of the auxiliary capacitor. The controller is electrically connected to the switching device and the auxiliary boost circuit. The input end of the voltage conversion device is electrically connected to the output end of the power factor corrector.

Disclosed are an inverter control device and method. The method according to an embodiment of the present includes estimating a rotation speed of a motor, determining a slip frequency reference using an energy of a direct current terminal capacitor of an inverter, which provides an output voltage to the motor, and a direct current terminal energy reference when a direct current terminal voltage of the inverter is a certain level or less, and providing a frequency reference determined by adding the rotation speed of the motor and the slip frequency reference to the inverter.

An electrical ride-through (ERT) unit is configured to apply a voltage to a drive circuit during disruptions of line voltage to the drive circuit. The ERT unit includes a capacitor on an ERT circuit that is prevented from applying the voltage to the drive circuit during normal operation of the drive circuit, and applies the voltage to the drive circuit during a voltage drop on the drive circuit.