Abstract: A method according to one embodiment may include selecting at least one power supply, among a plurality of different power supplies, and coupling at least one available power supply to a load. The method may also include selecting at least one charging mode, among a plurality of different charging modes, to charge a rechargeable battery. Of course, many alternatives, variations, and modifications are possible without departing from this embodiment.

Abstract: A method and system for operating a power converter having an electrical component and a switch coupled to a voltage source are provided. A signal is received that is representative of a desired current flow through the electrical component. A signal is generated that is representative of a difference between the desired current flow and an actual current flow through the electrical component. A duty cycle for the switch is calculated based on the signal representative of the difference and a voltage generated by the voltage source.

Abstract: A power supply system is provided that can operate with energy storage units of varying voltages and temperatures, that can correct voltage and temperature deviations, and that can continue to provide power when an energy storage unit is inoperable. A power supply system is also provided that can recondition an energy storage unit during vehicle operation.

Abstract: In a first embodiment, an information handling system (“IHS”) includes a processor. The IHS also includes a power rail coupled to the processor. The power rail supplies power, from a power adapter, to the processor. The IHS further includes a battery, that in response to a voltage fall on the power rail, supplies supplemental power to the power rail. In a second embodiment, an IHS includes a processor. The IHS also includes a power rail coupled to the processor. The power rail supplies power, from a power adapter, to the processor. The IHS further includes a battery, that in response to a voltage rise on the power rail, suppresses or sinks power supplied by the power adapter to the power rail.

Abstract: A charger of the present invention includes a charging transistor and a charging integrated circuit. The charging transistor is series-connected with a secondary battery to supply a charging current to the secondary battery. The charging integrated circuit is incorporated into a package having a higher heat releasability than that of the charging transistor. The charging integrated circuit controls the charging transistor and besides, supplies a charging current to the secondary battery. For this purpose, the charging integrated circuit includes a current source supplying this charging current. The charging current from the current source is supplied to the secondary battery together with the charging current from the charging transistor to charge the secondary battery.

Abstract: Peripheral devices that have their own power sources. In one embodiment, a peripheral device comprises a processing device, memory, and a power circuit configured to supply power to a peripheral device component, the power circuit including a power source.

Abstract: A power control apparatus of a complex terminal is disclosed that includes a DC/DC converter for outputting an auxiliary power supplied from an auxiliary battery after adjusting a level of voltage of the auxiliary power to a required input voltage level of the complex terminal; a second voltage sensor for measuring voltage of a main power outputted from a main battery, and controlling the auxiliary power of the auxiliary battery to be inputted to the DC/DC converter before the measured voltage of the main power becomes lower than a predetermined voltage; and a first voltage sensor for interrupting supply of the main power from the main battery to the complex terminal and controlling the auxiliary power outputted from the DC/DC converter to be supplied to the complex terminal, when the measured voltage of the main power becomes lower than the predetermined voltage.

Abstract: A circuit which extends the operational life of a main energy source coupled to a load, said circuit comprising a power generator having a heat source and a cooler thermally coupled to a thermoelectric generator (TEG) for converting thermal energy into electrical energy; and a first capacitor coupled to the TEG for receiving and storing the electrical energy from the TEG. The circuit further comprising at least one switching element coupled between the first capacitor and the load, a converter coupled between the capacitor and the at least one switching element for generating a regulated output, and a controller for activating the at least one switching element when the charge stored on the first capacitor reaches a predetermined level, thereby delivering power from the first capacitor to the load, via the converter, and reducing the amount of power drawn from the main energy source, thereby extending the operational life of the main energy source.

Abstract: In a co-generated power supply system for performing dispersed power supply to a load, a wind turbine generator, a solar cell and a fuel cell whose rated voltages are made equal to a rated voltage of a storage battery are used as DC power sources. These DC power sources, a commercial AC power source and the load are connected to each other via a bi-directional electronic transformer. Thus, the co-generated power supply system, in which the electric power of a natural energy system having many fluctuation factors is combined with stable electric power such as a load leveling battery or a fuel cell, allows the stable electric power to be supplied to the load via the electronic transformer commonly, thereby reducing the cost and enhancing the performance of the entire system.

Abstract: An apparatus, system, and method are disclosed to manage the generation and use of hybrid electric power. A monitoring module receives signals from one or more sensors. The signals comprise power level information of an electric energy storage device, power level information of one or more energy converters, and power level information of an electric load. A determination module compares the signals to determine whether electric power from the energy converters satisfies the electric load. A regulation module adjusts the electric power from the energy converters in response to a determination by the determination module that the electric power from the energy converters does not satisfy an electric load threshold.

Abstract: A distributed generation system is connected to an AC power line that provides AC electrical power from a source to a load. The distributed generation system includes a DC electrical power source, a capacitor for storing DC electrical power, a converter for converting electrical power stored in the DC electrical power source at a first voltage to a second, greater voltage for storage in the capacitor. The system includes an inverter for inverting the electrical power stored in the capacitor at the second voltage into AC electrical power having a peak voltage less than the second voltage. A controller is provided and operative for controlling the operation of the converter and the inverter to deliver electrical power stored in the DC electrical power source to the capacitor for delivery as AC electrical power to the AC power line.

Abstract: An electrical DC-to-AC power conversion apparatus is disclosed that is primarily intended for use with solar photovoltaic sources in electric utility grid-interactive applications. The invention improves the conversion efficiency and lowers the cost of DC-to-AC inverters. The enabling technology is a novel inverter circuit topology, where throughput power, from DC source to AC utility, is processed a maximum of 1½ times instead of 2 times as in prior-art inverters. The AC inverter output configuration can be either single-phase, split-phase or poly-phase.

Abstract: A portable power supply includes a housing, at least one battery cell, and an inverter connected to the at least one battery cell, wherein the inverter outputs at least about 3 kilowatts. A combination power supply and generator is also disclosed.

Abstract: A voltage converting unit converts a first voltage of an auxiliary power supply unit into a second voltage. A voltage determining unit determines whether the second voltage exceeds a predetermined threshold. A first switch, which is arranged between the voltage converting unit and a load, switches on and off a supply of an electric power of the second voltage to the load. When it is determined that the second voltage exceeds the predetermined threshold, a voltage-conversion control unit controls the voltage converting unit to stop converting the voltage, and then a switching control unit controls the first switch to supply the electric power of the second voltage to the load.

Abstract: A power supply device has first and second terminals, a transformer, a switching element and an auxiliary power supply element. The first and second terminals receive input power having an input voltage. The transformer has a primary winding and a secondary winding. The primary winding has a pair of winding terminals. One of the pair of winding terminals is connected to the first terminal. The switching element is connected between the second terminal and the other of the pair of winding terminals of the primary winding. The auxiliary power supply element feeds electric power to the transformer when the input voltage decreases to or less than a predetermined value. The auxiliary power supply element has a capacitor and a second switching element for storing energy from the primary winding into the first capacitor during a normal operation of the power supply device.

Abstract: Status of a bypass source of parallel-connected UPSs is determined from a load share when a loading of the parallel-connected UPSs meets a predetermined criterion. Status of a bypass source of the parallel-connected UPSs is determined from a bypass source voltage when the loading of the parallel-connected UPSs fails to meet the predetermined criterion. The loading may include an aggregate loading, and failure of a bypass source of a UPS may be identified responsive to detecting that a load share of the UPS is less than a predetermined proportion of the aggregate loading. Alternatively, failure of the bypass source may be identified by detecting that a bypass voltage fails to meet a predetermined criterion. Bypass circuits of the UPSs may be controlled responsive to a load share and/or a bypass source voltage.

Abstract: A propulsion system for a fuel cell hybrid vehicle that includes a fuel cell system and an EESS, where the propulsion system employs an algorithm for increasing system efficiency. A power limit value is defined as the maximum system efficiency times the charge/discharge efficiency of the EESS. If the vehicle operator requests a power greater than the power limit value, then the fuel cell system will preferably provide the power, and if the power request from the vehicle operator is less than the power limit value, then the EESS will preferably provide the power. The algorithm also considers changing operation conditions and parameters that impact the fuel cell system efficiency and the electric energy storage system efficiency, such as the state of charge of the EESS and regenerative braking.

Abstract: A power supply device includes two input ports, two output ports, a transformer having primary and secondary windings, a switch device, and a controller. The switch device includes a switching element connected in series with the primary winding, and a capacitor. The controller switches the switching element to energize the transformer and charge the capacitor. When an AC power failure such as instantaneous interruption occurs, energy stored in the capacitor is discharged to flow through the primary winding. Accordingly, the transformer is energized to maintain generating an output power from the power supply device for a certain time period. The capacitor is provided on a primary side of the transformer, generally higher voltage side, in the power supply device, so that a smaller capacitance of the capacitor can be used.

Abstract: Solar power tracking techniques are described herein. In one aspect of the invention, a solar power tracking apparatus includes, but is not limited to, a voltage converter and a controller coupled to the voltage converter. The voltage converter includes an input capable of being coupled to a solar power source and an output capable of being coupled to an electronic load, such as, for example, a portable electronic device. The voltage converter is configured to monitor or detect an amount of power drawn by the electronic load at the output of the voltage converter. In response to the monitored power drawn, the controller is configured to control the voltage converter to reduce amount of power to be drawn subsequently if the monitored amount of power exceeds a predetermined threshold. As a result, the output voltage from the solar power source is maintained within a predetermined range. Other methods and apparatuses are also described.

Abstract: Circuits and methods for supplying a temporary power supply at a predetermined voltage. A circuit includes a first DC/DC voltage converter that receives an input from a power supply at a first voltage level and generates an output at a second voltage level, higher than the first voltage level. The output is provided to charge a capacitor. A second DC/DC voltage converter has an input connected to the capacitor for drawing power from the capacitor at the second voltage level and generating an output voltage less than the second voltage level. The second DC/DC voltage converter further includes a feedback input that monitors the circuit's output voltage and activates the second DC/DC voltage converter when the output voltage falls below a predetermined threshold.

Abstract: An electronic apparatus system of this invention includes an electronic apparatus, and a fuel cell unit which is detachable from the electronic apparatus. The fuel cell unit incorporates a DMFC that can produce electricity by chemical reaction. On the other hand, the electronic apparatus has at least two operation modes having different power consumption amounts such as a normal mode and power saving mode. Upon switching the operation mode, the electronic apparatus advises the fuel cell unit accordingly. Upon reception of this advice, the fuel cell unit compares the current output electric power of the DMFC with the power consumption amount in the operation mode after switching, and returns a message based on that comparison result. The electronic apparatus switches the operation mode based on the returned message.

Abstract: A fuel cell system is provided that comprises a fuel cell for powering an electrical load, an oxidant supply device for supplying oxidant to the fuel cell, an energy storage device for providing at least temporary electrical power to drive the oxidant supply device and to the electrical load, and a control device which, in response to an increased power demand from the electrical load, directs the energy storage device to provide electrical power to the oxidant supply device, and then, when an increase in fuel cell power output has been detected, directs the energy storage device to provide electrical power to the electrical load. Methods for operating the fuel cell system are also provided.

Abstract: A multiple bi-directional input/output power control system includes a network of functional blocks housed in a single enclosure, providing DC power to one or more DC loads, and providing control and internal pathways, sharing one or more AC and/or DC power inputs. The system feeds back AC power from the DC power source into an AC input connection, and the fed-back AC power is shared by other AC loads. The system operates at least one alternative source of DC in a dynamic manner, allowing maximization of power generating capability at respective specific operating conditions of the moment.

Abstract: An engine starting assist system includes an auxiliary ECU having a voltage booster, an engine ECU, a starter relay, and a starter that allows the engine to be started when a current flows through the starter relay. The auxiliary ECU and the engine ECU are powered by a battery and supply currents to the starter relay. When the engine ECU resets the supply of the current to the starter relay because of a voltage drop of the battery during starting of the engine, the auxiliary ECU increases the voltage supplied from the battery using the booster, thereby supplying the current to the starter relay.

Abstract: A motor drive system includes a multi-output dc power source providing three or more output potentials, and a switching circuit including switching devices connected, respectively, with the output potentials of the multi-output power source. A controller determines a command apply voltage representing a desired voltage to be applied to the motor, and further determines a plurality of command share voltages corresponding to supply voltages of the multi-output dc power source, from the command apply voltage. The controller produces a pulsed voltage by driving the switching devices in accordance with the command share voltages.

Abstract: A system for supplying additional power to a module having an internal power supply, the system comprising: a module having an associated power supply, the power supply not being designed to accommodate power sharing; at least one load associated with the module, the load receiving power from the power supply; a variable current limited power source connected to the module supplying additional power to the at least one load; and a controller; whereby the variable current limited power supply is responsive to an output of the controller to vary the current limit of the variable current limited power supply.

Abstract: An electrical power feed for a submarine system and a method of supplying electrical power to the submarine system in which a plurality of power converters are used for feeding electrical power into the submarine system. A plurality of control circuits are each connected to at least one of the power converters and control the level of power output by the respective power converter(s) to which it is connected. Each power converter is connected to only one control circuit and at least some of the power converters operate independently from each other.

Abstract: The present invention is directed to an electrical system and method for providing power to a truck's cab while the truck's engine is turned off. An already available primary power supply of the truck and a secondary power supply generally located on a trailer being hauled by the truck, are used to charge auxiliary power storage units. The secondary power supply is further used to maintain charge of the auxiliary power storage units while the truck's engine is off. The system may provide power to electrical devices within the truck as DC, or as AC by means of an inverter. The system may further include thermostatic controls to protect the secondary power supply when high-voltage electrical devices such as space heaters are being used. Separate operating circuits are employed that include switching means to enable an operator to, or to automatically, control operation of the system.

Abstract: A method and system for standby lighting uses a power supply module and a standby lamp in conjunction with an HID lamp. The power supply module has a processor with smart trigger circuitry, soft start capability, overlap timer, and an advanced current sense algorithm. The power supply module continuously monitors the electronic ballast current to the HID lamp. If the current drops for a period of time, the power supply module supplies DC current to turn on the standby lamp gradually over a couple of seconds. The standby lamp is kept on while the processor checks for a rise in the electronic ballast current to a threshold current level for more than two seconds. Then, an overlap timer starts to count down for the time it takes for HID lamp to reach full intensity, approximately fifteen minutes. The standby lamp is turned off at the end of the count down.

Abstract: A method and apparatus for the voltage maintenance of an electrical AC voltage supply network comprising a partial converter system, which has a first branch pair and a second branch pair connected in parallel therewith and an electrical energy store connected in parallel with the branch pairs. Each branch pair is formed from two series-connected driveable power semiconductor switches, each with a diode reverse-connected in parallel, and the junction point of the power semiconductor switches of the first branch pair forming a first terminal and the junction point of the power semiconductor switches of the second branch pair forming a second terminal. The partial converter system has a third branch pair connected in parallel with the first and second branch pairs. The junction point of the power semiconductor switches of the third branch pair forms a third terminal.

Abstract: Circuits and methods for supplying a temporary power supply at a predetermined voltage are disclosed. A circuit includes first DC/DC voltage that receives an input from a power supply at a first voltage level and generates an output at a second voltage level, higher than the first voltage level. The output is provided to charge a capacitor. A second DC/DC voltage converter has an input connected to the capacitor for drawing power from the capacitor at the second voltage level and an generates an output voltage less than the second voltage level. The second DC/DC voltage converter further includes a feedback input that monitors the circuit's output voltage and activates the second DC/DC voltage converter when the output voltage falls below a predetermined threshold.

Abstract: In a control system of a regeneration system, electric power generated by a first electric generator is supplied to a first electric power storing device, and electric power is transmitted, via an intermediary device, between the first electric power storing device and a second electric power storing device which is provided separately from the first electric power storing device. The control system of a regeneration system includes determination means for determining whether or not an electric power generation amount of the first electric generator is equal to or larger than a predetermined amount, and electric power storing performance control means for determining whether or not the electric power of the second electric power storing device is to be supplied to the first electric power storing device via the intermediary device based on a determination result of the determination means.

Abstract: A fuel cell stack (7) with output lines (8, 9) has a bank of supercapacitors (10) or batteries (10a) connected across the output lines, either directly or through a DC/DC converter (22). The fuel cell stack receives fuel either from a reformer (13) or a source (13a) of hydrogen. Power is supplied through a power conditioning system (15) to a load (16), all under the control of a controller (19). The supercapacitors or batteries receive additional charge from excess power when there is a sudden decrease in the load, and provide charge to the output power lines (8, 9) when there is a sudden increase in load demand. In one embodiment, the voltage of the supercapacitors or batteries always follow the voltage of the fuel cell stack, thereby providing or receiving commensurate charge. With the DC/DC converter, the supercapacitors or batteries may be operated at voltages which are a multiple or a fraction of fuel cell stack voltage, and may have voltages boosted or bucked to aid in response to transients.

Abstract: This invention relates to a PFC circuit for an uninterrupted power supply. Such a PFC circuit includes a first converter, a second converter, an energy storing branch composed of two capacitors in series, and a controller. Each of the first and the second converters has an input terminal and two output terminals. The input terminal is connected with the AC live wire of the commercial power, while the two output terminals of each converter are connected in parallel with the two ends of the energy storing branch, with the parallel joints acting as the output terminal of the positive and the negative voltages respectively. The common nod of the two capacitors in series serves as the common output terminal of the positive and the negative voltages, and it is connected with the neutral of the commercial power.

Abstract: A power supply provided with: an AC/DC converter which receives AC power, converts the AC power into DC power, and outputs the DC power; a DC/DC converter which receives the DC power from the AC/DC converter, and controls a level of an output voltage of the DC/DC converter to be equal to a level of a voltage to be used by a load while the DC/DC converter supplies the output voltage to the load; a DC converter which is connected to an input of the DC/DC converter; and a DC power storage means which supplies electric power to the DC/DC converter through the DC converter.

Abstract: A hybrid power supply includes a switching type DC/DC boost type converter that receives energy from a primary battery cell and is arranged to deliver the energy to a rechargeable cell, set to provide a fixed output voltage that is less than the full charge voltage of the rechargeable cell. The hybrid power supply includes a circuit including a primary battery current control that senses primary battery current, and controls in part operation of the converter to provide constant current discharge on the primary battery side of the hybrid power supply.

Abstract: A power supply and switching technique is provided that utilizes a first battery and a second battery to charge a load. The power supply includes a first controlled power switch coupled to the first battery and the load, a second controlled power switch coupled to the second battery and the load, and a power controller coupled to the first controlled power switch, the second controlled power switch and the load. The power controller monitors the voltage and the load and causes a charge to be applied to the load when the load voltage is not a predetermined voltage. The power controller causes a charge to be applied to the load by selectively closing the first controlled power switch, thereby providing a charge from the first battery to the load, and/or selectively closing the second controlled power switch, thereby providing a charge from the second battery to the load. A similar switching technique may be used to recharge the first and second battery by alternately coupling them to an external power source.

Abstract: A hub supplying power actively includes an active power supply device having a battery charger, a storage battery, a DC/DC converter, and a control circuit. The hub is connected to a USB of a computer to receive direct current (DC) of the USB. When power demand of the hub is lower than the DC power supply of the USB, the power is supplied by the USB and the storage battery is charged via the battery charger simultaneously. When power demand of the hub is higher than the DC power supply of the USB, the storage battery discharges electricity and supplies power after conversion by the DC/DC converter. When the hub is disconnected to the computer, a power adapter is connected externally to rectify mains electricity and to charge battery. The charged battery outputs the power to supply for the connected peripheral equipment after converting the electricity into direct current.

Abstract: A power converter that can be used in a vehicle equipped with an electrical motor provides power to both the electrical motor and other, auxiliary loads, such as a headlamp, that require a different voltage. The power converter includes a first DC power supply that generates a first voltage equivalent to the voltage required by the auxiliary loads and a second DC power supply, connected in series with the first DC power supply, that generates a differential voltage, where the sum of the differential voltage and the first voltage is the voltage required to drive the electrical motor. A DC-DC converter is connected to the second power supply and converts the differential voltage to the voltage required to drive the auxiliary loads.

Abstract: Apparatus for electrically coupling a first digital device (408) and a second digital device (406) includes an interface circuit at the first digital device coupled at an interface node (230) to the second digital device. The interface circuit is configured to provide a first device supply voltage (Vcc2) to the interface node until a second device supply voltage (Vcc) at the interface node exceeds the first voltage. A data circuit (220) at the first digital device is coupled to the interface node. The data circuit is responsive to voltage on the interface node for providing digital logic signals at appropriate voltage levels to the second digital device.

Abstract: A portable power supply includes an engine-driven generator that generates a first AC power. A rectifier rectifies the first AC power to a first DC power. A DC/DC converter converts a second DC power from a storage unit to a third DC power. A controller selectively enables one or both of the rectifier and the DC/DC converter to provide one or both of the first DC power and the third DC power to the input of an inverter. The inverter converts the DC power at its input to a second AC power. Alternatively, the power supply advantageously includes a second generator and a second rectifier. The outputs of the two rectifiers are summed and the sum of the two outputs is provided as an input the inverter to extend the range over which a constant second AC power can be provided.

Abstract: An exchanger switch for use with a plurality of batteries that extends the useful life of the batteries. In a generator, a first battery can provide power to an external load while also providing power to recharge a second battery. When the first battery is depleted to a certain voltage level, the exchanger switch is activated and the second battery can begin providing power to the external load. The exchanger switch also directs a portion of the power from the second battery to recharging the first battery. The exchanger switch allows the generator to continue providing power to the external load without interruption. Using the batteries as alternating power sources allows the exchanger switch to increase the useful life of the batteries.

Abstract: A power supply and switching technique is provided that utilizes a first battery and a second battery to charge a load. The power supply includes a first controlled power switch coupled to the first battery and the load, a second controlled power switch coupled to the second battery and the load, and a power controller coupled to the first controlled power switch, the second controlled power switch, and the load. The power controller monitors the voltage and the load and causes a charge to be applied to the load when the load voltage is not a predetermined voltage. The power controller causes a charge to be applied to the load by selectively closing the first controlled power switch, thereby providing a charge from the first battery to the load, and/or selectively closing the second controlled power switch, thereby providing a charge from the second battery to the load. A similar switching technique may be used to recharge the first and second battery by alternately coupling them to an external power source.

Abstract: To enable a relatively constant output voltage at a DC/DC converter of a field device during a predictable time after shut-down of energy supplied to the DC/DC converter there is proposed a load voltage controller having a comparison unit adapted to compare the load voltage signal (Uo) with an externally supplied load voltage reference signal (Uref). When the load voltage (Uo) exceeds the load voltage reference signal (Uref) an energy buffer stores supplied energy for subsequent resupply to the load of the field device.

Abstract: The proposed voltage regulator has a power converter, a switch, a transformer, and a switching control device. The power converter is electrically connected to a power source for providing a voltage to compensate the output voltage of the voltage regulator when the output voltage is higher or lower than a predetermined level. The transformer is electrically connected to the switch for being used as a variable voltage source and the connecting configuration of the switch is determined by the input voltage. Also, the switching control device is electrically connected to the power converter for causing the voltage to have a phase shift with the input voltage and the inner product of the voltage and the input current being a positive value. The proposed control method is employed for generating a compensation voltage to stabilize the output voltage of the voltage regulator.

Abstract: A power supply and switching technique is provided that utilizes a first battery and a second battery to charge a load. The power supply includes a first controlled power switch coupled to the first battery and the load, a second controlled power switch coupled to the second battery and the load, and a power controller coupled to the first controlled power switch, the second controlled power switch, and the load. The power controller monitors the voltage and the load and causes a charge to be applied to the load when the load voltage is not a predetermined voltage. The power controller causes a charge to be applied to the load by selectively closing the first controlled power switch, thereby providing a charge from the first battery to the load, and/or selectively closing the second controlled power switch, thereby providing a charge from the second battery to the load. A similar switching technique may be used to recharge the first and second battery by alternately coupling them to an external power source.

Abstract: A plurality of electrical storage devices such as batteries capable of alternately storing and discharging electricity are connected to the power grid within existing rights of way. The electrical storage devices are batteries that may be alternately charged during periods of low power consumption and discharged during periods of high power consumption. In this manner, the power generating facilities can be operated at constant, or near constant generation, thereby optimizing the efficiency and productivity of the power generation. Significant amounts of power can then be stored within these batteries throughout the grid, thereby allowing the grid to meet peak loads by discharging the stored power during periods of high demand. Additionally, the placement of these batteries within existing rights of way allow the existing grid to be retrofitted to deliver more power without the need for costly and time consuming negotiations for new rights of way.

Abstract: An power supply apparatus for the input harmonic current suppression, input power factor compensation, and an output voltage regulation and a method thereof is provided. The power supply apparatus electrically connected to a AC power has a first power converter electrically connected in parallel with the AC power for providing a first compensating voltage and controlling the first compensating voltage to reduce harmonic components of an input current so as to cause the input current as a substantial sinusoidal wave and in phase with the input voltage, and a second power converter electrically connected in series with an output end of the power supply apparatus for providing a second compensating voltage in order to maintain the output voltage at a desired level and waveform. The related methods are also discussed.

Abstract: A method and system are described for providing a direct current (DC) uninterruptible power supply with the method including, for example: continuously supplying fuel to a turbine; converting mechanical power from the turbine into alternating current (AC) electrical power; converting the AC electrical power to DC power within a predetermined voltage level range; supplying the DC power to a load; and maintaining a DC load voltage within the predetermined voltage level range by adjusting the amount of fuel supplied to the turbine.

Abstract: The present invention is a battery transfer circuit connected to a load, a power supply for powering the load with at least a minimum supply voltage during normal operating conditions, and a source of battery voltage for powering the load during a power fail condition when the power supply is unable to power said load at the minimum supply voltage. The battery transfer circuit comprises a first circuit for applying at least the minimum supply voltage to the load during normal operating conditions and a second circuit for charging the battery to an optimal voltage greater than the minimum supply voltage and for down-regulating the optimal charge voltage to a predetermined voltage and for applying the predetermined voltage to the load during the power fail condition, wherein the predetermined voltage is less than the minimum supply voltage.