Abstract: A power supply that is capable of supplying power to an input/output channel for an Industrial Process Control System. The power supply includes a primary voltage converter having a first voltage input and a second voltage output, and overvoltage protection components that prevent the second voltage from rising above a predetermined maximum. The power supply includes a first low dropout regulator that is connected to receive the second voltage and to generate a third voltage, a second low dropout regulator that is connected to receive the second voltage and to generate a fourth voltage, and a third low dropout regulator that is connected to receive the fourth voltage and to generate a fifth voltage. The power supply provides an over-voltage fault tolerant self-testable architecture, allows for compact low cost individual channel isolation and fault tolerant EMI/RFI filtration.

Abstract: A device for balancing a plurality of at least two batteries or cells of a multicell battery comprises a multicell battery and a battery management system with a balancing circuit. Thereby all individual battery cells are connected to the battery monitoring system, wherein the battery monitoring system measures single cell voltage as well as the battery temperature and the current. The battery monitoring system is able to discern the lowest cell voltage and to discern a number of cells having a voltage higher than a determined maximum allowable voltage, which will be balanced until the charge imbalance decreases to an acceptable amount. The battery management system is active during charging and discharging of the multicell battery and the thresholds vary with the state of the battery.

Abstract: A power converter having an aircraft power source detector configured to limit the amount of power that can be drawn by the power converter when utilized in an aircraft. The power converter may detect an artifact of the aircraft power source, such as the 400 Hz ripple noise on an aircraft power line, or existing in the aircraft cabin, such EMI or aircraft lighting.

Abstract: A DC voltage converting device is on the output side connected to a DC voltage source and, on the output side, supplies a converted DC voltage to at least one electrical consumer via a cable connection. To improve such a DC voltage converting device in that also with high DC voltages on the input side, a conversion into another DC voltage is possible without any special constructional efforts and high costs while complicated cooling means or the like, are avoided at the same time, the DC voltage converting device comprises a plurality of DC voltage converting units of which each is serially connected to the DC voltage source on the input side and connected in parallel with the cable connection on the output side for supplying the converted DC voltage.

Abstract: The present invention is a system for providing power from solar cells whereby each cell or cell array is allowed to produce its maximum available power and converted by an operatively connected DC/DC converter. Each cell or cell array has its own DC/DC converter.

Abstract: The present invention includes: a first series circuit which is connected between one end and the other end of a DC power supply, and in which a reactor, a first diode, and a first capacitor are connected in series; a first switching element connected between the one end of the DC power supply and a connection point between the reactor and the first diode; a second series circuit which is connected to the first diode in parallel, and in which a second switching element and a second capacitor are connected in series; and a control circuit configured to control the on and off of the second switching element in order that turn on of the first switching element becomes to zero-voltage switching.

Abstract: Disclosed is a power supply (40) and a night vision device using the power supply (40). The power supply (40) comprises a battery (41), a power switch (42), a booster (43) for boosting a battery voltage provided by the battery (41) to an established voltage according to an operation of the power switch (42) and outputting a boost voltage, and a voltage selector (44) for comparing the voltage provided by the battery with a reference voltage (VR), outputting the boost voltage when the battery voltage is below the reference voltage (VR), and outputting the battery voltage when the battery voltage is beyond the reference voltage (VR). The night vision device is operable by voltages supplied from the power supply (40). According to the invention, stable voltages are supplied and batteries (41) are effectively used by supplying constant voltages in the case of using batteries (41) with different voltages, and hence, usage time of the night vision device is increased.

Abstract: An energy transfer circuit for connecting a load to multiple energy sources that can have different voltages. The energy transfer circuit connects the load and at least two energy sources, and has a control unit. The energy transfer circuit can transfer energy from at least one energy source to the load in response to the load's power demand; transfer energy from the load to at least one energy source in response to the load's charging current, and transfer energy between the energy sources. The energy transfer circuit also includes a first capacitor in parallel with the primary source and the load; a second capacitor in parallel with the secondary source, an inductor, a first switch between the inductor and the first capacitor, a second switch between the inductor and the second capacitor. The control unit opens and closes the first and second switches in response to the load and sources.

Abstract: Output voltages of regulators are supplied to each load device and input to a representing-value decision logic circuit that is operated by a dedicated resident power supply. The representing-value decision logic circuit selects an output voltage that appears the most irregular of all output voltages from the regulators, and then sends a selection result to a selector. The selector selects only the output voltage from a regulator that outputs the output voltage that appears the most irregular and is selected by the representing-value decision logic circuit and then outputs the output voltage to a smoothing circuit. The direct current that has been smoothed by the smoothing circuit is quantized by an AD converter and then received by a system monitoring processor.

Abstract: A switching apparatus that switches a connection state between two terminals, comprising a switch that switches the connection state between the two terminals according to a control voltage supplied thereto; a first power supply section that generates power supply voltage with a first voltage value; a second power supply section that generates power supply voltage with a second voltage value; and a driving section that, upon receiving switching instructions to switch the switch from a first state to a second state, uses power generated by the first power supply section to change the control voltage to be the first voltage value, and then uses power generated by the second power supply section to further change the control voltage from the first voltage value to the second voltage value, in the same direction and with a rate of change over time that is less than a rate of change over time used when changing to the first voltage value.

Abstract: A power supply voltage adjusting apparatus includes a voltage setting part that, according to a characteristic variation of a semiconductor integrated circuit, sets a first power supply voltage of a first power supply domain module among a plurality of modules in the semiconductor integrated circuit, each module respectively having a different power supply voltage; a detecting part that compares phases of a first clock signal flowing through the first power supply domain module and a second clock signal flowing through a second power supply domain module to detect a phase difference; and a voltage adjusting part that adjusts a second power supply voltage supplied to the second power supply domain module to reduce the phase difference detected by the detecting part.

Abstract: A load driving circuit that generates a desired voltage waveform to drive a load includes a target voltage waveform output section that outputs a target voltage waveform to be applied to the load. Power supply sections generate electrical power with voltage values different from each other. Negative feedback control sections between the power supply sections and the load supply electrical power from the corresponding power supply sections to the load and execute negative feedback control of a value of a voltage applied to the load for matching the voltage value and the target voltage waveform. A power supply connection section selects one of the power supply sections based on the value of the voltage applied to the load or the voltage value of the target voltage waveform and connects the selected power supply section to the load and disconnects the rest of the power supply sections from the load.

Abstract: A VSC converter includes in each valve one first semiconductor device of turn-off type with a voltage blocking capacity rating of a first, high level and connected in parallel therewith a series connection of a plurality of second semiconductor devices of turn-off type with a voltage blocking capacity rating of a second, lower level. A control arrangement of the converter is configured to switch a said valve into a conducting state starting from a forward biased blocking state of the valve by controlling the second semiconductor devices to be turned on and then the first semiconductor devices to be turned on with a delay, and at the end of the conducting state to turn off the first semiconductor device in advance of turning the second semiconductor devices off.

Abstract: Suppresses noise due to high engine speed and improves emission and fuel consumption of a hybrid generator. A difference computing unit 29 computes a first difference between an alternator output and a load output. A difference computing unit 31 computes a second difference between a battery output and the load output. When the battery output is greater than a battery output stopping threshold, the alternator output is fixed and the first difference is compensated for by the battery output. When the battery output is less than the battery output stopping threshold, the engine speed is increased to compensate for the second difference by the output of the alternator 3. To compensate for the second difference, a target engine speed is determined using a relationship of the second difference and the target engine speed. The engine speed is converged at the target engine speed.

Abstract: In methods and apparatuses at least one power supply is connected to at least one functional component. The power supply is also connected to an alternating current power source. The power supply provides power to the functional component when the functional component is operating in a relatively high power mode (normal operating mode). In addition, at least one energy storage device is connected to the functional component. The energy storage device supplies energy storage device power to the functional component when the functional component is operating in a relatively low power mode, such as a sleep mode.

Abstract: An airplane ground support system includes a multi-voltage power supply. This system includes an air conditioning module and a control module having a display and a processor, the display and processor presenting an airplane type or class selection menu to airplane support technicians and responding to the selection of a type or class of airplane by generating a power output selection signal designating the type of power needed by the selected type or class of airplane. The system also includes a power supply module which has an A.C. power input, at least one power output, and which receives the power output selection signal as an incoming signal. A power conversion system within the power supply module connects to the A.C. power input and supplies converted and voltage regulated power to the at least one power output. This power conversion system also receives the power conversion control signal as an input signal.

Abstract: A front-end converter in an uninterruptible power supply system includes: a boost circuit having first and second inputs, and positive, negative, and neutral output nodes, and being configured to provide a positive capacitor voltage between the positive and neutral nodes and to provide a negative capacitor voltage between the negative and neutral nodes; an inductor coupled to the first input; first AC and neutral AC inputs to receive AC power; a battery; a first device to selectively couple the inductor to the first AC input or a positive port of the battery; and a second device to selectively couple a negative port of the battery to the second input; where the inductor is shared between an online mode of the converter and an on-battery mode of the converter and the battery is coupled through the inductor to the first input during the on-battery mode.

Abstract: In a power conversion apparatus that converts AC power to DC power, an inverter circuit including one or more single-phase inverters connected in series with each other is connected in series at the subsequent stage of a rectification of an AC input. At the subsequent stage of the inverter circuit, a smoothing capacitor connected via a rectification diode, and a short-circuiting switch for bypassing the smoothing capacitor are provided. The short-circuiting switch is subjected to ON/OFF control by PWM control such that a voltage of the DC voltage supply of the inverter circuit follows a target voltage. The inverter circuit is subjected to output control such that a DC voltage of the smoothing capacitor follows a target voltage and an input power factor is improved.

Abstract: A universal power adapter has an input for receiving an input voltage from a power source and an output for supplying an output voltage selected from amongst two or more preset voltages. A voltage converter circuit converts between the input voltage and the two or more preset voltages. A connector tip connectable with the output connects one of the two or more preset voltages to the output.

Abstract: A detachable tip is used in conjunction with a power adapter to provide DC power to an electronic device. The tip includes an input connector which detachably mates with a connector which is electrically coupled to the power adapter. An output connector of the tip detachably mates with the electronic device. Conductors within the tip transfer the DC power from the input connector to the output connector to provide the DC power to the electronic device. Circuitry within the tip transmits to the electronic device, via the output connector, a power output indication signal representative of an amount of power available to be supplied to the electronic device by the adapter.

Abstract: An electronic card connector is used to connect an electronic card to an electronic device, such as a level-shifting device. The electronic card connector includes an insert slot unit and a switch unit. The insert slot unit is adapted for insertion of the electronic card and is provided with a power signal terminal for providing electric power to the electronic card that is inserted into the insert slot unit. The 10 switch unit is disposed in the insert slot unit, is operable to establish electrical connection between the power signal terminal and a first power source when the electronic card inserted into the insert slot unit does not actuate the switch unit, and is further operable to establish electrical connection between the power signal terminal and a second power source when the electronic card inserted into the insert slot unit actuates the switch unit.

Abstract: A converter to supply an AC voltage on a modulated signal output comprising two switching units each provided with a DC voltage input and a switching output to supply pulses varying between the voltage on the input in a first switched state, and a reference voltage in a second switched state, each switching unit comprising a first switch connected between the input and the switching output to establish said first switched state, said device comprising, for each switching unit, a second switch connected between said switching output and said modulated signal output to activate said switching unit, and a third switch connected between the input of said switching unit and the modulated signal output. An uninterruptible power supply provided with this converter.

Abstract: An apparatus and method for boosting output of a generator set are provided. The output of the generator set is connected to an electrical load. The apparatus includes an energy storage unit, and a power-electronic unit. The energy storage unit uses batteries and capacitors to store electric energy. The power-electronic unit measures an electrical parameter of the output of the generator set. Based on the measured electrical parameter and a predefined criterion, the power-electronic unit determines additional energy required by the electrical load. Thereafter, the power-electronic unit supplies the additional energy to the electrical load. The additional energy is drawn from the energy storage unit.

Abstract: A reception unit sequentially receives input of voltage values indicating an AC input voltage from an AC power supply. A ROM stores a power control table in which a power control parameter corresponding to the AC power supply voltage is matched with each group of the voltage values indicating the same AC power supply voltage. A decision unit determines to which group the received voltage values belong among the plurality of groups, whenever the reception unit receives the input of the voltage value and decides the group, to which a predetermined number of voltage values belongs among the plurality of voltage values sequentially received by the reception unit, among the plurality of groups using the determination result. A power control unit controls power supply according to the power control parameter matched with the decided group.

Abstract: An energy storage means for a drilling rig has a source of power, an AC bus connected to the source of power, a DC bus, a load connected to the DC bus, a rectifier connected to the AC bus and to the DC bus for converting AC power from the source of power to DC power to the load, and an energy storage system connected to the DC bus. The energy storage system can be batteries, capacitors or combinations thereof. A diode is connected between the energy storage means and the DC bus so as to supply power to the load when the DC voltage is less than a DC source voltage. The energy storage system has a nominal voltage slightly lower than a voltage of a AC-to-DC conversion by the rectifier.

Abstract: A system and method for operating a photovoltaic element at or near a maximum power point. A maximum power point tracker changes a voltage or current set point of a photovoltaic element in sequential discrete steps, measuring an output power at each step after a predetermined settling time. A slope of a power-voltage curve is then estimated and the slope is corrected for irradiance changes. Finally, an operating voltage or current of the photovoltaic element is adjusted based on the slope of the power-voltage curve and other factors, causing the photovoltaic element to operate at or near its maximum power.

Abstract: A semiconductor device (10) includes: an base substance (15) having a ferromagnetic material; a first semiconductor chip (11) and a second semiconductor chip (12) installed on the base substance (15); a first coil (131) installed on the base substance (15) and electrically connected to the first semiconductor chip (11); a second coil (132) installed on the first coil (131), electromagnetically connected to the first coil (131) and electrically connected to the second semiconductor chip (12); a transformer assembly (18) made of a ferromagnetic material and installed on the base substance (15), and a sealing body. The transformer assembly (18) includes a first core section (181), a first side shield section (182), and a first upper shield section (183).

Abstract: The embodiments disclosed herein are directed to methods and devices for a control system to regulate the output voltage of a high voltage power supply (HVPS) in an image forming device. In one embodiment, the HVPS comprises at least two voltage sources connected in series. A print engine controller is configured to disable at least one of the voltage sources when a voltage draw of a load exceeds a maximum differential voltage of the at least two voltage sources.

Abstract: A power converter includes an inverter circuit for superimposing a generated voltage on an AC input voltage, a diode bridge full-wave rectifying circuit connected to the inverter circuit, smoothing capacitors connected between DC output terminals of the rectifying circuit, short-circuit switches connected to the rectifying circuit, a rectification mode changing circuit connected to the rectifying circuit, a short-circuit switch control circuit for maintaining the short-circuit switches in an on state in a short-circuit phase range, a rectification mode control circuit for maintaining the rectification mode changing circuit in an off state in the short-circuit phase range and an inverter control circuit for PWM-controlling the inverter circuit so that an output voltage of the rectifying circuit follows a target output voltage when the rectification mode changing circuit is in the off state.

Abstract: A discharge share ratio calculation unit (52) calculates, for each power storage device, a remaining electric power quantity before an SOC is reached with respect to which an allowable discharge electric power is restricted, and calculates a discharge power share ratio between power storage devices according to the ratio of the remaining electric power quantity. A charge share ratio calculation unit (54) calculates, for each power storage device, a chargeable quantity before an SOC is reached with respect to which an allowable charge electric power is restricted, and calculates a charge power share ratio between power storage devices according to the ratio of the chargeable quantity.

Abstract: A device may include an interconnect module that includes a number of ports, where each port is configured to receive both an alternating current (AC) power supply and a direct current (DC) power supply; where the interconnect module provides power from the received power supplies to a plurality of field replaceable units (FRUs).

Abstract: An embodiment of a system for multiple source power conversion is implemented in a vehicle that includes an alternating current (AC) power source and first and second direct current (DC) power sources. The system includes an inverter, a DC-to-DC converter, and a controller. The controller receives external commands, inverter feedback signals, and DC-to-DC converter feedback signals, and executes and inverter control algorithm and DC-to-DC converter control algorithm. An embodiment of a method for multiple source power conversion between an AC power source, and first and second DC power sources includes receiving external commands from a remote source, inverter feedback signals from an inverter, and DC-to-DC converter feedback signals from a DC-to-DC converter. The method also includes executing an inverter control algorithm and a DC-to-DC converter control algorithm to generate drive signals for the inverter and DC-to-DC converter, respectively, based on the received commands and feedback signals.

Abstract: Methods and mechanisms to simultaneously regulate two or more supply voltages provided to an integrated circuit by a voltage regulator. In an embodiment of the invention, a voltage regulation message exchanged between the integrated circuit and the voltage regulator includes an identifier indicating two or more supply voltages selected from a plurality of supply voltages provided to the integrated circuit by the voltage regulator, where the voltage regulation message relates to the indicated two or more supply voltages. In another embodiment, the voltage regulation message indicates a desired supply voltage level to which the indicated two or more supply voltages are to transition.

Abstract: An electronic system which includes a power delivery surface that delivers electrical power to an electrical or electronic device. The power delivery surface may be powered by any electrical power source, including, but not limited to: wall electrical outlet, solar power system, battery, vehicle cigarette lighter system, direct connection to electrical generator device, and any other electrical power source. The power delivery surface delivers power to the electronic device wirelessly. The power delivery surface may deliver power via a plurality of contacts on the electrical device conducting electricity from the power delivery surface. The electrical device may be mobile device. Each contact may be shaped to improve power delivery reliability. The power delivery surface may further include circuitry to protect against accidental electrocutions.

Abstract: A power supply system is disclosed. The system comprises an AC power source from a power grid and a DC power source from an alternative energy source. The alternative energy source is a solar system in the preferred embodiment. The system provides a means of supplying the electrical appliance the DC power from the solar system with the higher priority. According to one embodiment of the present invention, a switch controlled by a controller provides a means of switching the power supply in between the two power sources without disrupting the operation of the appliance. According to another embodiment, a voltage regulator combines power generated from both sources to supply the power for the appliance with consuming the DC power from the solar system as the priority source.

Abstract: An integrated circuit is adapted to be selectively AC or DC coupled to an external device at a coupling point. The integrated circuit includes a first connector connected to the coupling point by way of a coupling capacitor for AC coupling, a second connector connected to the coupling point for DC coupling, and a switch to selectively short the first and second connectors and thereby the coupling capacitor, when the integrated circuit is DC coupled to the device. The switch may be a MOSFET bridge comprising a switch control MOSFET interconnected between the first and second connectors, with the switch control MOSFET receiving at its gate a mode status signal for turning on the switch control MOSFET and thereby shorting the MOSFET bridge when the integrated circuit is DC coupled to the external device.

Abstract: In embodiment, a power supply system is configured to use a linear regulator to form a regulated voltage during a standby mode and to use the regulated voltage to form another regulated voltage.

Abstract: An uninterruptible power supply has first and second input terminals, first and second inductors, first and second AC switch units, first and second storing devices and a control unit. The first and the second inductors are electrically connected to the first and the second input terminals. The first and the second AC switch units are electrically connected to the first and the second inductors for conducting input currents. The control unit is electrically connected to the first and the second AC switch units which may be turned on and off thereby to control the first and the second inductors which charge the input currents and discharge the input currents to the first and the second storing devices.

Abstract: The present invention relates to a method for supplying at least one load with electrical power. The at least one load is in this case supplied with power from an electrical DC voltage source and/or an electrical AC voltage source.

Abstract: A method for manufacturing a thin film photoelectric conversion module includes the steps of forming a plurality of photoelectric conversion elements connected in series on a substrate, and carrying out reverse bias processing simultaneously on a group of photoelectric conversion elements including a plurality of the photoelectric conversion elements positioned with one or a plurality of the photoelectric conversion elements interposed between each of them, by applying a plurality of voltages electrically isolated from one another to the group of photoelectric conversion elements.

Abstract: An aircraft device power supply is capable of connecting to either an AC or a DC power bus provided on an aircraft. When connected to an aircraft's AC power bus, an AC power signal is EMI-filtered, stepped down in voltage to the same voltage as that of the DC power bus, and then rectified. When connected to an aircraft's DC power bus, a DC power signal is EMI-filtered before it is merged with the rectified AC power signal via an AC/DC switchover subcircuit. The output of the AC/DC switchover subcircuit is input to a power factor correction subcircuit which outputs a boosted DC voltage, regardless of which of the AC or DC aircraft power buses is connected to the power supply. A step down converter reduces the boosted DC voltage to a lower, system voltage which may then be further reduced or modified, as appropriate for device to be powered.

Abstract: A universal power adapter has an input for receiving an input voltage from a power source and an output for supplying an output voltage selected from amongst two or more preset voltages. A voltage converter circuit converts between the input voltage and the two or more preset voltages. A connector tip connectable with the output connects one of the two or more preset voltages to the output.

Abstract: The present invention discloses a cooling-fan rotation-speed control circuit, wherein a plurality of sets of input power sources respectively having different voltages is electrically and parallel coupled to a cooling fan; a switch is installed between at least one input power source and the cooling fan; the switch is turned on/off according to a rotation-speed parameter to determine whether the cooling fan is driven by a low-voltage driving power or a high-voltage driving power.

Abstract: An exemplary multiplexed direct current regulation output circuit (2) includes a feedback circuit (22), a sampling circuit (30), a power control chip (21), a first output (27), a second output (28), a first half wave rectifier circuit (23), a second half wave rectifier circuit (24), a first filter circuit (25), a second filter circuit (26), a transformer (20), and a balance control circuit (29). The transformer is configured to provide low voltages to the first output via the first half wave rectifier circuit and the first filter circuit in series, and provide high voltages to the second output via the second half wave rectifier circuit and the second filter circuit in series. The balance control circuit is configured to control a voltage at the second output.

Abstract: A system for providing power from solar cells where each cell or cell array is allowed to produce its maximum available power and converted by its own DC/DC converter. In one form the system includes: one or more solar generators, each of which has at least one solar cell; a maximum power tracker operatively associated with each solar generator, where the maximum power tracker includes a buck type DC/DC converter without an output inductor, and the maximum power trackers of the solar generators are operatively connected in series with each other; and an inductor operatively connected to the series connected maximum power trackers.

Abstract: A power switch circuit includes a connector connected to a power supply, a detecting circuit, a first switch circuit, and a first conversion circuit. The connector is connected to the detecting circuit and connected to a first power terminal of a motherboard. The connector is connected to a second power terminal of the motherboard via the first conversion circuit and the first switch circuit, the detecting circuit outputs a corresponding control signal according to a type of the power supply to turn the first switch circuit and the first conversion circuit on or off to supply power for the motherboard.

Abstract: An electric power supply system is provided for feeding an output of a DC power source to a load at high efficiency and, without complicated controlling, for allowing for interchange of electric power among a commercial power system, a DC power source and a load. An electric power supply system includes a DC bus line for connecting a DC generator, a load and system power. The electric power supply system comprises a DC/DC converter connected between the DC generator and the DC bus line for controlling an output voltage to the DC bus line at a voltage V1; an inverter connected between the system power and the DC bus line for operating a control in response to an input voltage V2 from the DC bus line; and an AC/DC converter connected between the system power and the DC bus line for controlling an output voltage to the DC bus line at a voltage V3, wherein the respective voltages are set as V1>V2>V3.

Abstract: A switch device is brought into conduction in a case where a carrier takes a value zero to drt, a switch device is brought into conduction in a case where the carrier takes a value the drt to one, and one cycle of the carrier is divided into a period in which the carrier has a command value or more and a period in which the carrier has the command value or less. The periods are calculated by dst·T and drt·T, respectively. The same one as the carrier of a converter is employed in a carrier of an inverter, and based on the value drt set as a reference value, a command value of the inverter is provided in each of a side with a value larger than the reference value and a side with a value smaller than the reference value. The period in which the carrier takes the value or more is divided at a ratio among d0, d4 and d6, and the period in which the carrier takes the value drt or less is divided at the ratio among d0, d4 and d6.

Abstract: A power source system (1) operable to supply a load circuit (10) with electrical power, including a power-supplying source (2) including a plurality of power source terminals (3) and (4) that differ in output voltage from one another, in which the power-supplying source is operable to supply the electrical power through the plurality of power source terminals (3) and (4), a power source terminal-selecting unit (5) operable to select either one of the plurality of power source terminals (3) and (4), a plurality of voltage converting units (6) and (7) connected to the power source terminal-selecting unit (5) and operable to convert electrical voltage, and a voltage converting unit-selecting unit (8) operable to select either one of the plurality of voltage converting units (6) and (7). The power source system provides the proper supply of the electrical power in accordance with a status of the load circuit (10).

Abstract: There is provided a system for supplying power to a site having a load. The system comprises a number n of power source units, the value of n being greater than or equal to 3. The system further comprises a number t?tmax of loads groups, each load group having a number i of inputs. The value of i is greater than or equal to 2 and less than the value of n. Each load group receives power from i power source units, such that each load group is connected to a unique combination of i power source units. tmax is such that every possible combination of i power source units is connected to a unique load group.