Abstract: A load control module is provided for use with a transfer switch apparatus that controls the delivery of standby electrical power to a load during utility power interruption. The load control module selectively brings loads online to receive standby electrical power to prevent overloading of the electric generator that is providing the standby electrical power. The frequency of the electrical power is also monitored and if a low frequency condition is detected, loads are taken offline (shed). A method to flag those loads that induce an overload condition is also provided.

Abstract: A lighting system (1) has a first lighting circuit (2) configured to provide a first predetermined level of lighting intensity. The first lighting circuit (2) is configured to receive power from a mains electricity supply (3) or from a battery source (4) if the mains supply is unavailable. The first lighting circuit (2) is connected to at least one first Light source (5) and configured, when actuated, to provide lighting at the first predetermined level of lighting intensity. At this time, the first light source is in either an on or off state or a level of light required to raise ambient light level above a predetermined level. The system (1) further has a second lighting circuit (13) configured to provide lighting at least a second predetermined level of lighting intensity. The second lighting circuit (13) is configured to receive power from the mains electricity supply (3) and is connected to at least one second light source (14).

Abstract: A power transmission apparatus may comprise: a motor/generator unit configured to drive a motor with three-phase alternating current (AC) power converted from a supplied AC power or generating electrical power to supply AC power; a battery unit configured to charge electrical energy with direct current (DC) power and supplying the DC power by using the charged electrical energy; and/or a converter configured to convert the DC power supplied from the battery unit to the AC power to supply the AC power to the motor/generator unit or an external electrical grid based on control signals, or configured to convert the AC power supplied from the external electrical grid or the motor/generator unit to the DC power to charge the battery unit with the DC power based on the control signals.

Abstract: An automatic transfer switch to automatically electrically connect an electrical panel to a second power source, e.g., an electric generator, during interruption or failure of a first power source, e.g., a utility power supply, includes a powered interlock arrangement that is operative to prevent the electrical panel from being electrically connected to both power sources simultaneously.

Abstract: A bias circuit is disclosed. The bias circuit includes a first boost circuit, a first control circuit and a first switch circuit. The first boost circuit receives a first control signal and determines whether to be enabled accordingly. The first control circuit transmits the first control signal according to a first input voltage detected. The first switch circuit determines an open or a closed state according to the first input voltage, wherein when the first input voltage is equal to a predetermined voltage value, the first switch circuit closes and the first boost circuit controlled by the first control signal is to be disabled, and then the first boost circuit converts the first input voltage to a first output voltage, wherein the first output voltage is smaller than the predetermined voltage value.

Abstract: A new circuit and associated methods are disclosed for stealing power from HVAC circuit to supply relays and control circuits in an electronic thermostat, and protecting against damage to the relays from over-current condition. If a common connection is available, the circuit can obtain DC power always, if not available, the circuit can still obtain DC power when one of the relays is turned on, and the obtained power can be used to keep turning on the relay, making it possible to use economical and smaller form factor non-latching type relays or solid state relays, without wasting the limited battery charge. Compared with existing power stealing thermostat circuits, the disclosed circuit is advantageous due to its simplicity and no possibility of inadvertently turning on or off the HVAC.

Abstract: An electric-power supply device including: an electric-power supply unit configured to receive external electric power supply and to supply a first electric power; at least one electric-power generating unit configured to generate a second electric power; an electricity storing unit configured to store the second electric power; and a controller configured to control charging and discharging of the electricity storing unit and to control electric power supply, wherein the controller, in the normal mode, selects one of electric-power generating unit according to predetermined priorities assigned to the at least one electric-power generating unit, and the controller causes the electricity storing unit to charge the second electric power generated by the selected electric-power generating unit, and the controller, in the energy saving mode, terminates electric-power supply and causes the electricity storing unit to discharge electric-power causes the electricity storing unit to supply the second electric power.

Abstract: A power redundancy apparatus for a rack-mounted server may include a first server that includes first and second connectors connected in parallel to the output side of a first PSU, a second server that includes third and fourth connectors connected in parallel to the output side of a second PSU, and a power connection cable for coupling any one of the first and the third connectors, the second and the fourth connectors, the first and the fourth connectors, and the second and the third connectors.

Abstract: The invention relates generally to the field of barrier control systems and in particular relates to barrier control systems, such as a garage door opener, with auxiliary power supply and auxiliary power supply for barrier control systems. A barrier control system, such as a garage door opener, with an auxiliary power supply and an auxiliary power supply for a barrier control system are described. The auxiliary power supply includes a backup battery and a light source that is operable on DC power.

Abstract: A power storage system is provided with charge switches, discharge switches, a bidirectional DC/DC converter and a power storage system controller connecting all the battery packs to an external circuit to achieve parallel charge and discharge, and the power storage system starts the charge by setting a rated charge current value per one battery pack to Iset and setting the rated charge current value Iset as an initial value of a charge current command value Iref(1), thereafter monitor the charge current of each of the battery packs after elapse of a predetermined time so as to subtract its maximum value Ibmax(1) from the charge current command value Iref(1), and add the rated charge current value Iset to result of subtraction Ierr (Iref(1)?Ibmax(1)) so as to set as a new charge current command value Iref(2) and carry out pre-charge in such a manner as to carry on the charge.

Abstract: A practical product combining a thin film solar cell component with a residential environment is provided. Being flexible and easy to manufacture on a plane material, a silicon thin film solar cell is combined with a shutter used in residential buildings, thereby extending shutter functions. This module integrates energy saving, power generation and elegant appearance by bringing in a flexible and colored solar cell module that is light and thin and can generate power indoors and outdoors. As buildings are becoming higher nowadays, the area exposed to sunlight increases. Solar shutters have great power generation efficiency potential if used a building. The solar shutters can save energy and reduce CO2 emission when combined with electric products and provide electricity in emergency when combined with a storage device. The thin film solar cell provides components of many colors for customers, thereby providing options for the appearance of the building.

Abstract: An exemplary power supply module for distribution automation includes a manner of connecting an input power source to a power supply module and connecting an output of the power supply module to external devices, a manner of regulating, a rectification module generating output DC voltage, a transformer having a primary side connected with the regulating component and one or more power input power sources, and a secondary side connected to the rectification module, a manner of voltage feedback means for providing a voltage feedback signal to the regulating component to regulate the output DC voltage, and a load share control module having a load share signal for controlling load sharing for the power supply module. The power supply module includes a filter amplifier for conditioning the voltage feedback signal, where the filter amplifier is connected in the secondary side of the transformer for reducing noise in the power supply module.

Abstract: A control system is provided for controlling a load powered by an auxiliary power source during an interruption in the utility power source and/or during a power failure. The control system of the present invention provides power to essential loads in a dwelling as predetermined by a user and/or per the user's real-time instructions as the needs of the user may change. Additionally, the control system of the present invention automatically controls non-essential loads in order to maintain the auxiliary power load below the maximum threshold. Furthermore, the control system of the present invention allows the user to manually override all the controlled loads in an emergency or when the needs of the user change. Additionally, the control system of the present invention allows outside triggers to change the priority of the loads in real-time and can automatically change the priority due to predetermined tasks already running.

Abstract: A cooling system of a server with an AC power source and a DC power source includes an AC input subsystem, a DC input subsystem, and a driving control subsystem. The AC input subsystem receives an external AC power source and provides a first DC voltage and a second DC voltage. The DC input subsystem receives an external DC power source and provides a third DC voltage and a fourth DC voltage. When the external AC power source normally works, the driving control subsystem controls the first DC voltage and the second DC voltage to supply a high-voltage cooling apparatus and a low-voltage cooling apparatus, respectively. When the external DC power source normally works, the driving control subsystem controls the fourth DC voltage and the third DC voltage to supply the high-voltage cooling apparatus and the low-voltage cooling apparatus, respectively.

Abstract: Apparatus is described, for use with a cellphone (10) that has a power supply, in which the apparatus includes energy-storage apparatus (20), including a housing (26), a battery (28) coupled to the housing, and a cellphone interface (30) coupled to the housing, configured to electrically couple the battery to the power supply of the cellphone and to carry current from the battery to the power supply. Other embodiments are also described.

Abstract: An uninterruptible power supply (UPS) includes a frame, at least one AC input supported by the frame and configured to be coupled to at least one external power source and at least one AC output supported by the frame and configured to be coupled to at least one external load. The UPS also includes a power conversion circuit supported by the frame and having an output coupled to the at least one AC output, the power conversion circuit configured to selectively provide power from first and second power sources. The UPS further includes first and second static switches supported by the frame and configured to couple and decouple the at least one AC input to and from the at least one AC output and a control circuit supported by the frame and configured to cooperatively control the power conversion circuit and the first and second static switches.

Abstract: A system and a method for electricity management are disclosed. The system includes a data management unit, a cabinet, a control unit, an uninterruptible power supply apparatus and a power switch. The cabinet is powered by an external power supply. When the data management unit sends a testing instruction to the cabinet, the control unit controls the power switch to shut down the external power supply such that the cabinet is powered by the uninterruptible power supply apparatus instead. The control unit measures a set of battery parameters of the uninterruptible power supply apparatus, computes a power supply capacity of the uninterruptible power supply apparatus according to the set of battery parameters, and returns the power supply capacity to the data management unit.

Abstract: Systems and methods for monitoring an electrical energy storage unit and a parameter related to the load and based on the monitoring, if the load parameter is greater than a second rate of change of electrical power for a second component of an electrical power system, providing power from the electrical energy storage unit to the second component until the load parameter and the second component have equivalent rates of change of electrical power.

Abstract: Disclosed is a current diverting device adapted to be electrically connected with a battery pack arranged to power a machine including at least a first operating unit. The battery pack includes a positive and a negative pole and a plurality of battery cells interconnected between the poles such that at least two battery cells are connected in series for providing a higher battery pack voltage level, and is further arranged to feed electricity to the at least one first operating unit via the battery poles. Also disclosed is a method and a computer program product.

Abstract: The invention relates to a system for managing the supply of energy for a number n of local energy networks where n?2, each local energy network comprising at least one client device. Said system comprises a switching device connected to each network, an energy storage means, and a station for supplying the n networks with energy via switching devices, the station receiving the energy from a supply system, and the station is configured to determine and assign to each switching device: A first mode wherein the energy storage means supplies energy to said network; or A second mode wherein the station supplies energy simultaneously to said network and to said energy storage means.

Abstract: A ferroresonant transformer is adapted to be connected to a primary power source, an inverter system, and a resonant capacitor. The ferroresonant transformer comprises a core, a main shunt arranged to define a primary side and a secondary side of the ferroresonant transformer, first windings arranged on the primary side of the ferroresonant transformer, second windings arranged on the secondary side of the ferroresonant transformer, and third windings arranged on the secondary side of the ferroresonant transformer. The first windings are operatively connected to the primary power source.

Abstract: An isolated mid-sized centralized photovoltaic solar station that includes a solar panel subsystem that converts photon energy into electricity, and a battery subsystem an energy reservoir to store electrical energy generated by the solar panel subsystem. A control unit regulates the output of energy from the solar panel system onto a low voltage electrical system that provides electrical power to electricity consuming devices or systems. The electrical system may operate at less than 50 volts thereby make the protection system less expensive. Furthermore, some of the batteries in the station may be mobile, so that they can be transported and used external to the station.

Abstract: A frequency regulation method for a grid which is performed by a control device that connects, through a communication network, a controller for controlling at least one load device and a storage battery. The frequency regulation method including: obtaining, when it is detected that a frequency of a grid deviates from a predetermined range, an instruction signal including a power instruction value for keeping the frequency of the grid within the predetermined range; and generating a control signal for controlling the load device when the load device is operable in accordance with the instruction signal, and transmitting the control signal to the controller, and generating a control signal for charging or discharging the storage battery when the load device is not operable in accordance with the instruction signal, and transmitting the control signal to the storage battery.

Abstract: For each of consumers, a connection control apparatus is provided that includes an opening/closing device capable of connecting or disconnecting an electric power system and a consumer, that, when a power outage occurs in the electric power system, disconnects the electric power system and the consumer from each other by the opening/closing device at a command from an outage management apparatus or the like, and that connects the electric power system and the consumer to each other by the opening/closing device upon receiving a command from the outage management apparatus or the like at the time of restoration from the power outage. A power supply control apparatus supplies electric power from energy provision equipment to electrical appliances during a power outage in the electric power system.

Abstract: A second DC power-supply voltage that is obtained by outputting a first DC power-supply voltage obtained by converting an AC power supply into a direct current in an AC-DC converter circuit, through a first switch for PWM switching is smoothed and fed to a load as an output DC power-supply voltage. The first DC power-supply voltage is also supplied to a battery through a third switch for PWM switching and the battery is thereby charged. Further, a third power-supply voltage output from the battery is output to the output side of the first switch through a fourth switch for PWM switching.

Abstract: A backup power management system connectable to a primary power source and a secondary power source, and a method of operating the same. The system includes an enclosed housing that receives a control system including first and second controllers that are connected to a first transfer switch contactor and a second transfer switch contactor within the housing. Both the primary power source and a secondary power source are broken into two separate output supplies. The two separate output supplies from the primary power source and the secondary power source are each provided to one of the first and second transfer switch contactors. The control system sends signals to the first and second transfer switch contactors to control the movement of the contactors between first and second positions. The power management system can also include a load management controller to control the load on the secondary power source.

Abstract: An apparatus and a method for power supply are provided. In the invention, the residual standby power can be quickly discharged by an additional fast discharging unit within a predetermined time when an external AC power (for example, city power) received by the power supply apparatus capable of supporting ATX (Advanced Technology Extended) specification is disappeared (for example, power trip). Accordingly, any host system applied with the inventive power supply apparatus and method would not be in crash when the received external AC power (city power) is recovered, and thus effectively promoting the stability of the applied host system.

Abstract: A power management system has power supplying means, measuring means that measures power generation environment for the power supplying means, and communication means that transmits information measured by the measuring means. The power management system comprises: a control unit that controls the measuring means and the communication means. The power supplying means is used as a power source for the measuring means and the communication means. The control unit sets a first power threshold to be used for determining whether or not to switch operation states of the measuring means and a second power threshold to be used for determining whether or not to switch operation states of the communication means on the basis of a power supply that is supplied from the power supplying means.

Abstract: An electrical system and method include a DC link, a controlled rectifier connected between the DC link and a power source, an energy storage, a DC to DC converter connected between the DC link and the energy storage, a motor, and a DC to AC converter connected between the DC link and the motor. The converters are configured to transfer power in both directions. The rectifier controls the DC voltage of the DC link when the DC link voltage is in a first voltage range. The DC to DC converter controls the DC voltage of the DC link by charging the energy storage when the DC link voltage is in a second voltage range, which has higher voltage values than the first voltage range, or by discharging the energy storage when the DC link voltage is in a third voltage range, which has lower voltages than the first voltage range.

Abstract: A method can include receiving a potential value of a negative electrode of a lithium-ion cell and, for a cell charging process for the lithium-ion cell, adjusting a constant voltage phase voltage based at least in part on the potential value of the negative electrode. Various other apparatuses, systems, methods, etc., are also disclosed.

Abstract: Described is a digital electrical routing control system for use with electrical storage systems and conventional and alternative energy sources, and methods of using the same. In one aspect is described a method of determining an amount of energy used by a load using a computer, with the energy being provided from a first battery and a second battery, and with other energy being supplied to charge the first battery and the second battery, the method comprising the steps of: initiating, using the computer, charging of the first battery with the other energy while the second battery is being drained by connection to the load; initiating, using the computer, charging of the second battery with the other energy while the first battery is being drained by connection to the load; and detecting, using the computer, an amount of energy consumed during an interval of time based upon an amount of charging of the first battery and the second battery during the interval of time.

Abstract: The present invention provides an electronic device, a power supply control chip and a power supply control method. The electronic device includes: at least one element (10); a rechargeable battery (12); an adapter socket (14); a first processing circuit (16) having a first operation state and a second operation state; a power supply judgment parameter acquisition module (18) configured to acquire a power supply judgment parameter; and a control module (20) configured to control the first processing circuit to operate in the first or second operation state based on the power supply judgment parameter. In the first operation state, the first processing circuit (16) is configured to convert a first electrical signal output from a adapter into a second electrical signal and charge the rechargeable battery (12) with the second electrical signal.

Abstract: A battery powered device that interfaces with the power source of a target device, such as a lamp, and detects when the primary power source has been removed. When the primary power source is available, the battery is charged and when the primary power source is not available, the battery drives an illumination device to provide emergency safety light to an area.

Abstract: An energy storage system, more particularly, a grid-connected energy storage system including a renewable energy generation system. The energy storage system includes a compensation unit for storing or outputting electric energy generated from a renewable energy generation system including a plurality of renewable energy generation modules; and a power managing system for converting power generated from the renewable energy generation system into power for driving a load, outputting the load, and operating the compensation unit when a mismatch loss is generated so that entire output power from the renewable energy generation system is smaller than the sum of maximum power of the renewable energy generation modules.

Abstract: The disclosed distributed power supply system does not become disconnected from a grid simultaneously with others when the grid voltage falls instantaneously. In a distributed power supply device which controls an inverter circuit 10 based on a control signal obtained by comparing a predetermined carrier signal and voltage command signals of three phases and which converts DC power to AC power and supplies the AC power to a power grid of a three-phase AC power supply, fundamental wave signals of three phases are generated from a grid voltage of the three-phase AC power supply. A reference cosine wave signal is generated from the fundamental wave signals of three phases. A third harmonic signal is generated from the reference cosine wave signal and the fundamental wave signals of three phases. The three-phase fundamental wave signals and the third harmonic signal are added to generate voltage command signals of three phases.

Abstract: There is provided an apparatus including a power control apparatus for supplying power from an external power source or power from private power supply equipment to a plurality of electrical appliances, the power control apparatus including a power failure detection device for detecting an interruption of power supply from the external power source and for measuring a power supply interruption duration, a storage device for storing power supply information regarding power supply from the private power supply equipment to the electrical appliances, and a power supply control device for controlling the power supply from the private power supply equipment to the electrical appliances based on the power supply information stored in the storage device when the power supply interruption duration measured by the power failure detection device is in excess of a predetermined time period.

Abstract: An electrical system architecture has at least two sources of electrical power, each delivering power to an individual AC bus. The individual AC buses are connected by a tie bus. A first source of electric power delivers power into a first AC bus, and the first AC bus delivers power to a first set of users. A supply current sensor is between the first source of power and the first AC bus. A tie bus output sensor senses output power from the AC bus being delivered onto the tie bus. A plurality of user output current sensors sense current passing to each of the plurality of users. A control is operable to compare a sensed current in the supply current sensor, and sum the current in the tie bus output sensor, and the plurality of user output sensors. If the sum of the output sensors differs by more than a predetermined amount from the current sensed by the supply sensor, the control identifies a fault. The first AC bus is then disconnected from the tie bus.

Abstract: A system for controlling an electricity supply to a load comprises at least one battery for storing energy. The system also comprises a controller for determining when to switch between a first mode wherein electricity is supplied to the load from a mains electricity circuit; and a discharging mode wherein electricity is supplied from the battery to the load via the mains electricity circuit. The determining is based on information associated with the electricity supply.

Abstract: Disclosed are a battery protection device and method for DC power supply. The device comprises: a first branch circuit unit and a second branch circuit unit; a monitoring unit is connected with a DC power supply, the first branch circuit unit and the second charge circuit unit respectively; the first branch circuit unit and the second branch circuit unit are connected in parallel, with one end connected to the DC power source and the other end connected to the load units in series via a battery unit; when the monitoring unit detects that the DC power supply supplies power normally, it controls the first branch circuit unit to conduct, the DC power supply supplies power to the load units; when the monitoring unit detects that the DC power supply supplies power abnormally, it controls the second branch circuit unit to conduct, the battery unit supplies power to the load units.

Abstract: An automation system including a plurality of peripheral devices, each configured to perform at least one function relating to energy consumption in a facility and an automation controller in communication with the plurality of peripheral devices and providing for the control of the performance of the function by each device, wherein the system includes a configurable transfer switch that enables the system to control the flow and/or source of electricity provided to circuits in a facility.

Abstract: A ferroresonant transformer comprises a core, a main shunt, first windings, second windings, and third windings. The main shunt arranged relative to the core to define a primary side and a secondary side of the ferroresonant transformer. The first windings are arranged on the primary side of the ferroresonant transformer and are operatively connected to the primary power source. The second windings are arranged on the secondary side of the ferroresonant transformer and are operatively connected to the secondary power source. The third windings are arranged on the secondary side of the ferroresonant transformer and are operatively connected to the resonant capacitor. When a primary signal is present on the first windings, a first output signal is present on at least a portion of the third windings. When a secondary power is present on the second windings, a second output signal is present on at least a portion of the third windings.

Abstract: The uninterruptible illumination system contains at least a lighting device and a power detection device which is connected to a power supply line. There is a light generation element and a driver and communication module in each lighting device. The power detection device is wireless-linked with the driver and communication module. The power detection device detects the electrical condition on the power supply line. When the voltage on the power supply line is normal, at least a light device is able to provide illumination. On the other hand, when the voltage on the power supply line is not normal or there is no electricity, the driver and communication module receives a signal from a wireless transmitter of the power detection device, the stored electricity of an electricity provision unit of the driver and communication module is used to maintain the operation of the light generation element.

Abstract: A power supply circuit supplies power to a load from a main power source or an auxiliary power source. The power supply circuit includes a hybrid selection unit that selects one of the main power source and the auxiliary power source and supplies power to the load from the selected one, a voltage comparing unit that compares a voltage of the main power source and a voltage of the auxiliary power source, and a power source control unit that controls the auxiliary power source in accordance with a comparison result of the voltage comparing unit, and supplies a voltage higher than the voltage of the main power source by a predetermined voltage to the load from the auxiliary power source through the hybrid selection unit.

Abstract: In one technique of the present invention, DC electric power from a DC bus is inverted to provide AC electricity to one or more electrical loads, and AC power from a power generating device is rectified to provide a first variable amount of electric power to the DC bus. This technique also includes determining power applied to the electrical loads, and dynamically controlling the amount of power supplied from the power generating device and an electrical energy storage device in response to the power applied to the loads.

Abstract: A distributed electrical power system includes a first AC generator configured for supplying an AC voltage; a second AC generator configured for supplying the AC electrical voltage; an AC power distribution network connected to the first AC generator and the second AC generator for receiving the AC voltage, the AC power distribution network including a two or four-wire AC power distribution circuit; at least one (solid state circuit breaker (SSCB) module remotely located for receiving the AC voltage from the power distribution network; a system controller connected to a data bus for controlling operation of the at least one power distribution module; and at least one contactor for selectively switching supply of the AC voltage to the at least one power distribution module from either the first AC generator or the second AC generator upon failure of either of the first AC generator or the second AC generator.

Abstract: A home energy management apparatus and method for interworking with a new renewable energy are provided.

Abstract: A method is provided for detecting islanding conditions in an electric power network which includes a plurality of sub-networks. The sub-networks include at least one power electrical unit and are separable from each other and a main grid supplying the network by switching devices. The method includes determining topological information of at least one sub-network of interest, detecting islanding conditions in at least one sub-network of interest on the basis of the topological information by using separate detecting devices for each sub-network of interest, and sending, on the basis of the islanding conditions detected by using the detecting devices, a disconnect signal to at least one power electrical unit in at least one sub-network of interest.

Abstract: A combined battery charger and motor driver circuit assembly includes a plurality of power transistors arranged as a planar array, a cold plate configured to couple heat from each of the transistors in the array, a conductive power coupling fitting (also termed a bus bar), at least one capacitor, and a ferrite bead filter surrounding a necked section of the bus bar. The bus bar has a plurality of individually electrically conductive layers, each two of the layers being separated by an insulating layer, each conductive layer providing a plurality of contacts, the contacts in a layer configured to provide electrical contact, in the alternative, for power transistor collectors or power transistor emitters. The laminated bus bar is extended to form a fishtail shape along a specified section distal to the power transistors. The fish tail section terminates in two electrical contacts configured to provide electrical contact via discrete conductors to respective positive and negative battery terminals.

Abstract: [Problem] To provide a power supply system which effectively utilizes a power storage unit and also limits degradation of the power storage unit. [Solution] A power supply system (1) is provided with: a power storage unit (2) for charging supplied electric power and supplying the charged electric power by means of discharge; and a power storage unit controller (3) for controlling the discharging of the power storage unit (2). The power storage unit controller (3) sets a discharge period during which the power storage unit (2) can be discharged. Furthermore, during the discharge period, the power storage unit controller (3) determines the electric energy to be supplied by means of the discharging of the power storage unit (2) during the remaining discharge period on the basis of the remaining discharge period and the electric energy that can be discharged by the power storage unit (2).

Abstract: A battery power supply device is provided. The battery power supply device includes: an input unit that receives external power; a battery power unit that is connected to the input unit to charge a battery with the external power; a current detection unit that detects a current that is supplied to a load and that provides the current to the battery power unit; and an output unit that provides the external power and battery power from one node to the load and that receives a load current from the battery power unit to adjust output of the battery power.