Abstract: The invention concerns a method for controlling a direct voltage source with a first direct voltage source (2) and a voltage monitoring device (24), which monitors an output voltage of the first direct voltage source (2) and acts upon a control device (31), the control device (31) controlling the working state of the first direct voltage source (2). Further, the invention concerns a voltage supply device (22) with which the method can be used. In this connection it is endeavored to reduce the risk of an increase in voltage in a circuit with several direct voltage sources. For this purpose, a second direct voltage source (3) produces a voltage change at the voltage monitoring device (24).

Abstract: A regulator circuit may be configured to operate with multiple power supplies. The regulator circuit may be configured to receive an input voltage and provide a regulated output voltage at an output terminal as a function of the input voltage. The regulator may include at least two drivers. A first driver may have a driver output coupled to the output terminal and have a supply terminal coupled to a high power supply, and a second driver may have a driver output coupled to the output terminal and have a supply terminal coupled to a low power supply. A selector circuit may be configured to compare the input voltage with a control voltage that has a magnitude just below a magnitude of the low power supply, to determine which driver to select from the first driver and the second driver, and enable either the first driver output or the second driver output to be active according to which driver has been selected.

Abstract: A power supply for use with a tissue stimulating prosthesis, such as a cochlear implant. The power supply system comprises a first battery cell, a second battery cell, at least a third battery cell and a switch. The first and second battery cells are electrically connected in series to provide power to components of the prosthesis, while the third battery cell is configured to be selectively electrically connected in parallel with either the first or second battery cells.

Abstract: A protection device for non-common ground buses is disclosed. The protection circuit includes a controller, a level shifter, a first group of switches, and a second group of switches. The controller together with the level shifter controls the first group and second group of switches. The non-common ground buses will be isolated when at least one group of the switches are turned off in an abnormal condition.

Abstract: A control device for voltage regulation of a power supply bus, including a first switch adapted, when in a closed position, to connect an electrical energy generator to an energy storage device, and a second switch adapted, when in a closed position, to short-circuit said generator, said generator being connected to said power supply bus if said first and second switches are in an open position, which control device further including first means for generating a signal for controlling said first switch and second means for generating a signal for controlling said first switch, said first and second means for generating a signal for controlling said first and second switches, respectively, being separate means operating independently of each other.

Abstract: A method and apparatus for transferring AC electrical power to a load from a first power source to a second power source provides for a time delay in the transfer to avoid problems associated with differences in the phases between the power sources. The phase of the voltage waveform from each power source is sensed continuously, and the phase difference is known at all times, so that it can be used when the transfer is necessary. The method and apparatus monitors the voltage from the first power source, and initiates the transfer from the first power source to the second power source in response to an unacceptable condition from the first power source. The second power source is connected only after waiting for a period of time corresponding to the appropriate time delay.

Abstract: A fan power supply system having a pair of voltage supplies, one producing a higher voltage than the other. A switch selects one of the voltage supplies in response to a control signal. A DC/DC converter is connected to the selected one of the voltage supplies for producing a current greater than current fed to the DC/DC converter by the selected one of the voltage supplies. A fan is fed by the current produced by the DC/DC converter. The fan produces a train of pulses representative of the rotational speed of the fan. A microcontroller encodes the train of pulses produced by the fan as a function of whether the selected one of the pair of voltages has the higher voltage or the lower voltage. A decoder produces the control signal in accordance with the encoding by the microcontroller.

Abstract: An electrical device for automatically combining two input power source supply circuits with either aligned or unaligned phases, into a single operational circuit, with an output load capacity totaling approximately the sum of the two lower capacity power supply circuits. The device and adapters, through a series of coupled relays and contactors, incorporates internal circuitry and components which sense the phase relationship and alignment of the supply circuits, and depending upon conditions chooses the correct path, and automatically connects the supply circuits to the load circuit without the need of manual switches, or additional adapters.

Abstract: The present invention is a device that includes a rectifier and a super capacitor packaged together in a single housing. The device has a first connection point that is coupled to the rectifier input. The output of the rectifier is coupled to a first side of the capacitor and to a second connection point of the device. The second side of the capacitor is coupled to ground through a third connection point. The device is operable to receive AC power and provide DC power. Moreover, through the operation of the super capacitor, the device will provide DC power for a time after AC power has been removed.

Abstract: Systems and methods are disclosed for a two-source series inverter. The systems and methods combine operation of a first voltage source and a second voltage source in series powering a novel voltage combining arrangement and a conventional inverter via a switch configuration to power a load. The switch configuration is controlled by a plurality of control signals generated by a controller based on a variety of control modes, and feedback signals.

Abstract: An integrated circuit (100) is provided with power regulating circuitry (104) serving to actively regulate the voltage difference between a first power supply rail Vdd and a second power rail Vss being used to supply electrical power to processing circuitry (102). A voltage regulating capacitor Ca has one terminal connected to the first power rail Vdd and a second terminal selectively connected to either the second power rail Vss or a third power rail Vdda. Should a voltage undershoot be detected by voltage sensing circuitry 106, then the capacitor Ca is connected to the third power rail Vdda so as to dump at least part of charge Ca, Vdda in capacitor Ca onto the first power rail Vdd and resist the voltage drop. During normal operation, charge is accumulated into the capacitor Ca. An additional load device T2 is provided to lower the voltage difference should an overshoot be detected.

Abstract: The present invention relates to battery power peripheral devices such as MP3 players which are also periodically connected to another power source such as a mains wall socket or USB cable power bus. In particular, but not exclusively, the present invention relates to regulation of these voltage sources. In general terms the present invention provides a multiple supply rail for the load regulators of a power supply circuit for a battery powered device. One supply rail is coupled to the battery, and another is coupled to a non-battery source such as an external mains regulated source and/or a bus power wire from a USB cable or similar. The regulators have multiple inputs, each for taking their input voltage from one of these supply rails.

Abstract: Certain embodiments provide a circuit breaking link status and reporting system. The system includes a power source and a circuit breaking link in communication therewith. An electrical outlet is in interruptible power supply communication with the circuit breaking link. A sensor is in interruptible electrical communication with the circuit breaking link and configured to generate a signal indicating whether the circuit breaking link is open. A local processor communicates with the sensor and is configured to determine whether the circuit is open. A communications bus is in communication with the local processor and configured to receive signals from the local processor. A processor is in communication with the local processor through the communications bus and configured to receive information regarding the status of the circuit breaking link. A communications port is in communication with the processor and configured to send information regarding the status of the circuit breaking link over a network.

Abstract: The invention relates to the supply of lamps (8?, 8??) of at least two different lamp types, of which a first lamp type (8??) has a wattage which is approximately a whole multiple of the wattage of a second lamp type (8?), whereby the same ballast devices (1) are used, embodied for the direct supply of the second lamp type (8?) and which may be operated in parallel for the supply of the first lamp type (8??). The correct connection of a suitable lamp (8?, 8?, 8??) to the ballast device (1) is monitored by means of a signal exchange between ballast device (1) and lamps (8?, 8?, 8??) before switching on the supply line of the ballast device (1).

Abstract: A system and method for detecting islanding in a Distributed Generation utility grid is described. In some examples, the system, via an inverter, injects a frequency disturbance to a location of the utility grid associated with a DG generator, measures both the frequency error due to the disturbance and the frequency drift of the location of the utility grid, and determines islanding based on a maximum value of the frequencies. In some cases, the system is able to reduce or minimize the Non-Detection Zone of the inverter by detecting islanding without always relying on a detectable frequency error due to an injected waveform.

Abstract: An apparatus and method for controlling a supply voltage of a multiple interface card includes a first voltage adjustment unit, a second voltage adjustment unit, an internal circuit, a first voltage controller, and a second voltage controller. The first voltage controller adjusts a first supply voltage to a first internal supply voltage used as an operating voltage of the internal circuit and supplies the first internal supply voltage to the internal circuit. The second voltage adjustment unit adjusts a second supply voltage to a second internal supply voltage used as an operating voltage of the internal circuit and supplies the second internal supply voltage to the internal circuit. The first voltage controller detects the first supply voltage and, according to the first supply voltage, either applies the first supply voltage to the first voltage adjustment unit or blocks the first supply voltage from the first voltage adjustment unit.

Abstract: A system for reducing power loss in a medical apparatus may include multiple power sources, a power source switch matrix, a diode, and a diode bypass switch. The power source switch matrix may control whether each power source is currently providing power to the power load. The diode may be electrically coupled to a first power source to prevent current from one or more of the other power sources from being applied to the first power source. The diode bypass switch may be coupled to the first power source and is operable to switch between a first state in which a current pathway from the first power source to the power load includes the diode and a second state providing a current pathway from the first power source to the power load that circumvents the diode.

Abstract: A power supply device incorporated in a vehicle driven by an internal combustion engine including: a first power supply system for driving a vehicle load that converts an output of a generation coil provided in a generator driven by an internal combustion engine into a DC output to supply the DC output to an electrical load or electrical loads in the vehicle; and a second power supply system for driving an external load that converts an output of another generation coil provided in the generator into a DC output, then converts the DC output into an AC output at a commercial frequency with an inverter, and supplies the AC output to an external load, wherein the inverter is operated as a DC-DC converter to supply assisting power from the inverter through a switch to the first power supply system, when the output of the first power supply system is insufficient.

Abstract: An apparatus, system, and method for providing DC battery backup power to Power over Ethernet, (PoE) Mid Span or End Point Power Sourcing Equipment, (PSE), such that in the event of the loss of utility power the PSE device is able to continue to provide power for some time while battery capacity remains. The apparatus includes an AC to DC converter that receives an AC power input and outputs DC power to the power over Ethernet circuitry and a DC battery pack that provides backup DC power to the power over Ethernet circuitry.

Abstract: A power supply circuit includes first and second power supply circuits. The first power supply circuit has a first voltage generation circuit and the second power supply circuit has a second voltage generation circuit and an operational amplifier. When a load is in a low power consumption mode, only the first power supply circuit operates to output a first voltage to the load. When the load is in a normal operation mode, the second power supply circuit also operates to output a desired power supply voltage based on a reference voltage generated by the second voltage generation circuit. In this case, the operational amplifier controls not only the second power supply circuit but also the first power supply circuit. Thus, a desired power supply voltage is output to the load regardless of whether the first voltage is greater than the desired power supply voltage.

Abstract: In order to provide a bearing for an already prepositioned switching shaft, fitted with coupling levers, of a low-voltage circuit breaker in the region where the switching forces act, a bearing assembly is provided. The bearing assembly includes a bearing body which is mounted on the housing front wall of the switch pole, surrounding the switching shaft in the form of a half shell. The bearing body includes a subregion which projects between two coupling levers, which are at a distance from one another and are connected to a movable switching contact. It thus forms side guide surfaces for the coupling levers. Such a bearing assembly can be arranged in both the end regions of the switching shaft in multipole circuit breakers.

Abstract: The present invention provides systems and methods that allow for individual power sources to be disconnected and reconnected without interrupting the power supply from the other power sources and that allow for these power sources to provide power at substantially the same electrical parameters such as frequency, phase, and voltage.

Abstract: A reliable uninterruptible DC power supply device. The DC backup power supply device includes an AC/DC converter, a DC/DC converter, voltage step-up/down choppers and a battery connected to a DC path of a main circuit connected with a load via a switch, and a microcomputer. In the device, under control of the microcomputer, the voltage step-up/down choppers are first operated under a condition that the MOS FET was turned OFF for self diagnosis of the backup power supply device. Next, the switch is turned ON to execute the remaining self diagnosis. The DC backup power supply device can execute its self diagnosis with a reduced likelihood of danger of exerting an adverse effect on the main circuit and also can exhibit a reliable uninterruptible power supply function.

Abstract: An auxiliary lighting system contains at least one photoelectric cell to convert ambient light into energy and at least one light emitting diode. The photoelectric cell converts ambient light into energy which is stored in a storage cell. A switching system provides energy from the storage cell to the light emitting diode upon certain conditions, generally by time or by lack of ambient light.

Abstract: A cellular inverter generates an alternating output voltage by a succession of serial combinations of DC voltage electrical sources that are available to it within switchable cells and, within a serial combination currently in use, by a voltage regulation using high-frequency chopping. This voltage regulation exhibits a certain lag and allows through an undesirable voltage step during the repositioning of its operating range caused by a change of the serial combination currently in use. The cellular inverter proposed comprises, in its high-frequency switch-mode voltage regulation circuit illustrated in the figure, a pre-compensation circuit that allows the lag to be compensated for and this undesirable voltage step to be considerably attenuated.

Abstract: A device package that receives a voltage from a power supply on a motherboard and that includes provisions for a voltage control element that controls the power supply voltage. The provisions for the voltage control element are such that the voltage from the power supply has a first voltage if the voltage control element is installed and a second voltage if the voltage control element is missing. Such a device is useful in (computer) systems having wiring boards with power supplies that produce output voltages that depend on adjust voltages on adjust inputs. The provisions of the device package can then set the adjust voltage such that the power supply has a first voltage if the voltage control element is installed and a second voltage if the voltage control element is missing.

Abstract: A transfer switch, for use in connecting a series of electrical loads to an auxiliary power source, e.g. an electrical generator, includes a series of switches that are interconnected with the electrical loads, and a controller interconnected with certain of the switches. The controller actuates the switches in a predetermined order of priority, to supply power to selected electrical loads. In the event actuation of one of the switches results in an overload condition, the controller deactuates the switch and subsequently reactuates the switch after a predetermined delay. When all of the switches are actuated, the controller monitors the level of electrical load on the auxiliary power source, and de-actuates all of the switches in the event of an overload condition. The switches are then reactuated in the order of priority to restore power to the loads. Additional switches may be manually operated to supply auxiliary power to other loads.

Abstract: An electronic AC power source voltage regulator with the UPS function is provided. The proposed electronic power source voltage regulator includes: an input port, an output, a switch set electrically connected between the input port and an AC power source, a capacitor, an inductor, and an electrical energy converter including an electrical energy storage device, a first output terminal, and a second output terminal. The electrical energy converter of the proposed electronic power source voltage regulator transfers an electrical energy of the electrical energy storage device into the output voltage to be output so as to stabilize the output voltage when a significant voltage difference of the AC power source occurs.

Abstract: An actuator and movement linkage system for moving a load, such as a control surface of aircraft, in relation to a carrying structure includes an electric motor system, an actuator device connectable or connected to the load to move the load, the actuator device connected to the electric motor system to be driven thereby, and transfer units provided for mechanically connecting the actuator device to move the load.

Abstract: A power supply switching circuit arrangement is configured to provide a relatively smooth (low noise) power supply switch-over during the transition between active and quiescent modes. Complementary inputs of an operational amplifier are selective coupled to feedback paths to the amplifier and the power supply switching circuit arrangement, so as to bias a switching transistor during system active mode at a value that is just slightly below the turn-on voltage of the transistor. This means that turning on the switching transistor for the purpose of providing quiescent mode powering of the utility device requires only a small transition in control voltage from an active mode ‘almost turned-on’ level.

Abstract: The invention relates to an electrical power supply system for feeding electrical loads, having at least two electrical energy stores, a circuit for connecting the electrical energy stores to an electrical d.c. network with loads and at least one power generator, wherein each energy store can be connected to the d.c. network by activating switching elements by means of d.c. transformers.

Abstract: A reverse current protection device includes one or more contactors in a power circuit that open to prevent current flow and close to allow current flow; an impedance buffer to invert voltage across the diode; a threshold detector to compare inverted voltage to a reference voltage to determine a good or fault diode condition; an opto-isolator actuatable by the threshold detector when at least one of a good diode condition is determined and a fault diode condition is determined; and a relay in communication with the opto-isolator to cause at least one of the one or more contantors to close in a good diode condition and open in a fault diode condition.

Abstract: A power supply unit (system power supply IC) has a multiplicity of power supply circuits providing for different supply voltages. Should an abnormal condition take place in any of the multiple power supply circuits, the power supply circuit suffering the abnormality issues an abnormality detection signal that contains a power supply circuit number and an abnormality type, which signal is stored in a nonvolatile memory together with time data indicative of the time of reception of the abnormality detection signal before all the power supply circuits are disabled. Thus, this arrangement protects the system power supply IC and the loads connected thereto, and provides convenient means for analyzing the abnormality and replicating it if necessary, based on the abnormal power supply circuit number, abnormality type and time data stored in the nonvolatile memory.

Abstract: An emergency lighting system powers all the luminaires of a lighting system during normal use, and switches from utility power to an emergency power source to drive some of the luminaires during a power outage. The typical on/off wall switch control for regular use carries out an automatic system test routine every time it is switched off. First, the non-emergency luminaires are extinguished, the emergency luminaires are activated for a time-limited period, and the system reverts to regular utility power and on/off control by the wall switch.

Abstract: An apparatus and method for event triggering an electronic device utilize an AC adaptor port as a trigger source interface port. The apparatus for triggering the device comprises an AC adaptor port, a mode control element, and an event monitor. While in a trigger mode, the AC adaptor port is the trigger source interface port and, while not in trigger mode, the AC adaptor port is a power source port. The method of triggering comprises the steps of setting a mode of operation, wherein trigger mode is either enabled or disabled, and while trigger mode is enabled, monitoring a parameter of a signal applied to the AC adaptor port, comparing the parameter to a threshold to determine if a trigger event has occurred, and if so, triggering the device to perform an action.

Abstract: A host device such as a camera, PDA, etc. can have an attachment such as a wireless modem, with both host and attachment having respective batteries. Some loads in the host are always powered by the host battery, and some loads in the attachment are always powered by the attachment battery, but some other loads in the attachment are selectively powered by either the host or attachment battery depending on a power consumption and/or the relationship between the charges remaining in the batteries.

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 a transfer switch connectable to the primary and secondary power sources, and a plurality of circuit branches connected to the transfer switch. The circuit branches include first and second remotely operated branches having first and second managed circuit breakers, respectively. The system further includes a controller connected to the first and second managed circuit breakers. The controller controls the managed circuit breakers, thereby controlling the current through the first and second managed circuit branches.

Abstract: The present invention is directed to a precise power system which utilizes two separate inverters fed by a rectifying power supply from a generator set. During normal operation, the first or critical inverter would feed the critical load(s) and the second or non-critical inverter would assist the electric utility in feeding the non-critical load(s). During utility grid failure, the second inverter is disconnected from the power supply so that the entire output of the generator set is available to the critical load. During generator set failure, the utility grid powers the second inverter to supply power to the first inverter for the critical load(s).

Abstract: A system for operating in parallel plural non-break power units, each unit including an inverter inserted between an input power source and a parallel bus and an AC switch inserted between the bypass power source and the parallel bus and having an inverter power supply mode via the inverter and a bypass source power supply mode via the AC switch when the inverter stops. Each unit includes a switch driver for generating an AC switch driving signal in response to an inverter power supply signal based on the output signal of a sequence control circuit. Inverter mode signal output terminals are mutually connected. The switch driver generates the relevant AC switch driving signal on the basis of an inverter supply signal synthesized on a per-unit basis.

Abstract: Methods and systems for protecting integrated circuits (“ICs”) from power-on sequencing problems provide an interim voltage during power-on sequences in order to prevent over-voltage conditions across IC terminals. Voltages at first and second terminals of a circuit are monitored and an interim voltage to the second terminal is provided when the voltage at the first terminal exceeds a first threshold and a voltage at the second terminal is below a second threshold. The interim voltage protects the circuit from excessive voltage differences across the first and second terminals during power-on sequences, and is deactivated during normal operation so as not to draw excessive current. The method/system helps to insure that multi-supply dependent logic and/or other circuitry does not receive inappropriate voltage levels, and thus helps to insure that lower voltage level based circuitry is not damaged during power-up, transients, and/or glitches.

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: An apparatus for and a method of controlling standby power to minimize energy consumption in a standby mode. The standby power control apparatus includes a control unit, a power supply unit, a constant voltage unit, and a standby power generation unit. The control unit controls an overall operation of the system. The power supply unit converts an alternating current (AC) power into a direct current (DC) voltage and outputs the DC voltage to a load. The constant voltage unit drops the output DC voltage of the power supply unit and provides the control unit with the dropped output voltage. The standby power generation unit drops the output voltage of the power supply unit from a first value to a second value lower than the first value if the system is switched to a standby mode.

Abstract: Disclosed herein is a switching constant-current power supply which comprises: a switching-system power converter for supplying a predetermined current to a load; a current detector for generating a feedback signal in correspondence with the load current; a controller for driving the power converter in correspondence with the feedback signal; and a feedback circuit, which is provided between the current detector and the controller, and comprises a signal holding unit, the feedback circuit supplying either a first feedback signal, output from the current detector, or a second feedback signal, output from the signal holding unit, to the controller; the size of the second feedback signal being approximately equal to the first feedback signal at a given time.

Abstract: A telecommunications power system includes a power bus and a battery module with a plurality of batteries. A contactor connects the batteries to the power bus. A distribution module and a plurality of rectifier modules are connected to the power bus. A plurality of loads are connected by the distribution module to the power bus. A controller disconnects the batteries using the contactor when a voltage of the batteries falls below a low voltage disconnect threshold when AC power is lost and/or the rectifier modules fail. The controller minimizes current surge and high voltage transients when the rectifier modules begin providing power and the contactor closes to reconnect the batteries to the power bus. To minimize current surge and high voltage transients, the controller lowers a voltage of the rectifier modules to the voltage of the batteries before the contactor reconnects the batteries to the power bus.

Abstract: A computing system includes a motherboard including one or more connection subsystems, each of which includes a port connector and a device interface circuit conditioning signals transmitted or received through the port connector. The port connector includes a connection-sensing terminal, which is connected to ground through a cable, and which is allowed to float to a voltage supplied through a pull-up resistor when the cable is disconnected. The motherboard also includes a main voltage plane supplying electrical power to a separate voltage plane for each device interface circuit only when a cable is connected to the port connector which is also connected to the device interface circuit.

Abstract: An apparatus and method for the protection of an electronic circuit against anomalies in a supplied power voltage where the apparatus includes: a reserve power source connected to the supplied power voltage for providing voltage to the electronic circuit for a predetermined amount of time after an anomaly has occurred in the supplied power voltage, a module control for maintaining selected data and control signals transmitted to the electronic circuit during occurrence of the anomaly, and a differential comparator connected to the supplied power voltage and to the reserve power source to produces a comparator control signal upon occurrence of the anomaly, the differential comparator providing the comparator control signal to the module control.

Abstract: Apparatus for automatically selecting one of two or more available power supply voltages for use as a main power supply of a PCI adapter is described. In one embodiment, a power supply selector is designed such that the presence of a positive voltage at a Vaux input thereof prevents power at a Vcc input thereof from driving a main power supply input to a PCI adapter. Conversely, the absence of a positive voltage at the Vaux results in the main power supply input to the PCI adapter being derived from the Vcc input. In an alternative embodiment, jumpers are provided for enabling a user to select which power supply will be used as the “default” power supply for the adapter.

Abstract: A power controller includes power storage means for storing DC power from DC power generation means that. Power conversion means include a DC/DC converter that converts a voltage when receiving a DC input. Charge and discharge means discharge electric power from the power storage means to the power conversion means and charge DC power from the DC power generation means in the power storage means. The charge and discharge means are provided among the DC power generation means, the power storage means and the power conversion means. Detection means detect electric energy of an external power load to which power from at least the power conversion means is supplied. Control means control operation of the charge and discharge means on the basis of the detected electric energy.

Abstract: A method for conversing battery power for a battery-optimized system-on-a-chip begins by sensing for presence of an alternate power source. The processing continues, when the presence of the alternate power source is detected, a first control loop of a first DC-to-DC converter is disabled and a second control loop of a second DC-to-DC converter is enabled to produce a supply voltage for the system-on-a-chip. The first DC-to-DC converter, when enabled, converts a battery voltage into a supply voltage and the second DC-to-DC converter, when enabled, converts voltage from the alternate power source into the supply voltage.

Abstract: A local power generation system generates a substantially DC voltage at an inverter input, which is modulated to generate a resulting output AC power signal to a load. The inverter input voltage may be obtained from an engine generator, providing an AC power signal that is rectified, or from a fuel cell generator providing a DC voltage that is converted to the desired voltage value at the inverter input. An energy storage device helps maintain the DC voltage when load power draw increases, until the engine (or fuel cell reaction) accelerates enough to accommodate the increased power demand. The system may also be used in an uninterruptible power supply (UPS) application, in which the load draws power from a utility-provided AC power source until a fault condition appears. When the fault condition appears, the load switches its power draw from the utility-provided AC power source to the inverter output.