A system and method for combining power from DC power sources. Each power source is coupled to a converter. Each converter converts input power to output power by monitoring and maintaining the input power at a maximum power point. Substantially all input power is converted to the output power, and the controlling is performed by allowing output voltage of the converter to vary. The converters are coupled in series. An inverter is connected in parallel with the series connection of the converters and inverts a DC input to the inverter from the converters into an AC output. The inverter maintains the voltage at the inverter input at a desirable voltage by varying the amount of the series current drawn from the converters. The series current and the output power of the converters, determine the output voltage at each converter.

The disclosed invention is intended to prevent malfunction of an internal circuit because of unwanted power supply switching caused by a noise during operation of a semiconductor device powered by a backup power supply, while eliminating wasteful consumption of the backup power supply. A first switching transition time after coupling the main power supply terminal to the internal power supply node until decoupling the backup power supply terminal from the internal power supply node is made longer than a second switching transition time after coupling the backup power supply terminal to the internal power supply node until decoupling the main power supply terminal from the internal power supply node.

The disclosed invention is intended to prevent malfunction of an internal circuit because of unwanted power supply switching caused by a noise during operation of a semiconductor device powered by a backup power supply, while eliminating wasteful consumption of the backup power supply. A first switching transition time after coupling the main power supply terminal to the internal power supply node until decoupling the backup power supply terminal from the internal power supply node is made longer than a second switching transition time after coupling the backup power supply terminal to the internal power supply node until decoupling the main power supply terminal from the internal power supply node.

An automotive power supply device includes first and second batteries, first and second load groups, a plurality of fuses interposed between the first and second batteries and the first and second load groups, and instantaneous interruption prevention devices. First and second redundant system loads that complement operation of each other are allocated to the first and second load groups. The instantaneous interruption prevention devices are connected to the first and second load groups, and prevent an instantaneous interruption of electric power supplied to at least any of the first and second load groups when one or more fuses are blown.

A voltage selection circuit, including: first and second nodes of application of first and second input voltages; a third output voltage supply node; first and second MOS transistors respectively coupling the first and third nodes and the second and third nodes; and a control circuit capable of keeping the first and second transistors either respectively on and off or respectively off and on, the control circuit including a feedback loop from the third node to the gate of the first transistor and being capable, during a transition phase, of controlling the first transistor in linear operating region to apply a DC voltage ramp to the third node.

A medical tool includes: a tool main unit configured to be driven in response to a power supply; a first power supply configured to be removable from the tool main unit; and a second power supply having a smaller power capacity than the first power supply, and configured to be charged by the first power supply. The tool main unit is configured to be driven by receiving power supply from one of the first power supply and the second power supply.

A system in a wireless network comprising a tower, a first radio unit, a power supply unit, a supplementary power source and a power control unit arranged to supply electric power to the first radio unit. The power control unit is operative to obtain a scheduled power demand related to an amount of electric power required in the first radio unit for transmissions scheduled in an imminent time interval as a resource block or subframe. The power control unit is further operative to supply electric power to the first radio unit from the power supply unit if the power demand does not exceed a power threshold, or from the power supply unit and the supplementary power source if the power demand exceeds the power threshold.

Methods, systems, and computer readable media can be operable to facilitate a testing of an unknown USB supply that is connected to a CPE (customer premise equipment) device to determine a current draw capacity of the USB supply. The CPE device may test the USB supply to determine whether the USB supply is capable of supplying a predetermined current. If the determination is made that the USB supply is not able to supply the predetermined current, an end-user may be instructed to plug an alternative PSU (power supply unit) into the CPE device, wherein the alternative PSU is capable of supplying the predetermined current to the CPE device. The CPE device may output an indication that an alternative PSU should be used via a graphics output to a display device through an HDMI (high-definition multimedia interface) connection or via an LED indication using one or more LEDs at the CPE device.

A vehicle power supply circuit including a power source input for receiving an input current having an input voltage is disclosed. A first branch and a second branch are each connected to the power source input. Each branch includes a converter for converting the input current to an output current. A first distribution unit is connected to each converter for receiving the output current and includes a plurality of first outputs for supplying power to a plurality of loads.

A system and method for combining power from DC power sources. Each power source is coupled to a converter. Each converter converts input power to output power by monitoring and maintaining the input power at a maximum power point. Substantially all input power is converted to the output power, and the controlling is performed by allowing output voltage of the converter to vary. The converters are coupled in series. An inverter is connected in parallel with the series connection of the converters and inverts a DC input to the inverter from the converters into an AC output. The inverter maintains the voltage at the inverter input at a desirable voltage by varying the amount of the series current drawn from the converters. The series current and the output power of the converters, determine the output voltage at each converter.