Abstract: A power measurement system for multiple power sources includes a plurality of measurement apparatuses, a multiplexer, and a processing module. Each of the measurement apparatuses has a sense resistor and a sense amplifier. The sense resistor is electrically connected to a power source at one terminal thereof and electrically connected to a load at the other terminal thereof. The sense amplifier receives a voltage difference across the sense resistor, amplifies the voltage difference by a gain value, and outputs an amplified sense voltage. The multiplexer receives the amplified sense voltages and outputs one of the amplified sense voltages. The processing module receives the one amplified sense voltage outputted from the multiplexer and calculates an output power of the power source according to the one amplified sense voltage. Furthermore, a method of operating the power measurement system is provided.

Abstract: Systems and methods for switching between voltages are provided. One system includes an output, first and second switches coupled to the output. The system also includes a first transmission gate coupled to the first switch and a second transmission gate coupled to the second switch. One method includes receiving, at the first transmission gate, a first pair of complementary voltages and receiving, at the second transmission gate, a second pair of complementary voltages. The method further includes selecting the smallest voltage amongst both pairs of complementary voltages and outputting a third pair of complementary voltages. In one method, the first pair of complementary voltages includes a first negative voltage and a positive voltage, the second pair of complementary voltages includes a second negative voltage and the positive voltage, and the third pair of complementary voltages includes the smaller of the first and second negative voltages and the positive voltage.

Abstract: A power distribution grid comprising a plurality of cells configured to be electrically connected to each other and a power management system. A cell in the plurality of cells is configured to distribute electrical energy to an area corresponding to the cell. The cell has a plurality of entry nodes configured to allow the electrical energy to flow into the cell. The power management system is configured to manage a distribution of the electrical energy to the area by the cell independently of the distribution of the electrical energy to other areas by other cells in the plurality of cells.

Abstract: A switching power supply includes a rectifying unit configured to rectify an input alternating voltage, a storage unit configured to smooth the voltage rectified by the rectifying unit and store as a DC voltage, a pulse signal generation unit configured to generate a pulse signal from the DC voltage stored in the storage unit, and a detection unit configured to detect that a commercial alternating current power supply has been turned off based on the pulse signal generated by the pulse signal generation unit.

Abstract: Systems and methods of providing power with an uninterruptible power supply are provided. The uninterruptible power supply includes a first input to receive an input AC voltage from a power source, the input AC voltage having an associated phase angle, and a second input to receive an input voltage from a backup power source. The uninterruptible power supply also includes an output. The output provides output power derived from power from at least one of the power source and the backup power source. The uninterruptible power supply also includes an inverter coupled to the backup power source, a relay and a controller. The relay is configured to couple the first input with the output in a first position, and to couple the inverter with the output in a second position.

Abstract: A power converter includes a first power input to receive AC input power, a second power input to receive backup power, a first DC bus configured to provide a positive DC output voltage, a second DC bus configured to provide a negative DC output voltage, and a power conversion circuit coupled to the first DC bus and the second DC bus. The power conversion circuit has an inductor, a first switch device coupled in series with the inductor, a second switch device coupled in series with the first switch device, and a bypass relay coupled in parallel with the second switch device. The power conversion circuit is switchably coupled to the first power input and the second power input, and is operable to charge the inductor and generate the positive and negative DC output voltages.

Abstract: The battery pack that recognizes operation voltage of a corresponding device according to a unique resistance of the connected device and sensed through a third external terminal of the battery pack, the battery pack having a plurality of cells that can be coupled in series or in parallel to be suitable for an operation voltage of the corresponding device. The battery pack can be sold to a consumer to enable the consumer to power a variety of different electrical appliances. Alternatively, the battery pack can be incorporated into a chassis of an electrical apparatus so that the battery pack can be sold to many different manufacturers of electrical appliances.

Abstract: A power Y-adapter provides power at a high voltage to an output end from at least two input ends to which power of a lower voltage and a phase difference is provided and includes a first polarity sensitive current isolation device, a second polarity sensitive current isolation device, a control section, and an output section. When the voltage signals supplied to the hot wire terminals of the first input connector and the second input connector sufficiently are out of phase, the Y-adapter can produce a voltage of higher magnitude between the first and the second hot wire terminals of the output connector.

Abstract: An appliance including an electrically-powered system, a primary power input, and an auxiliary power input is provided. The electrically-powered system is disposed within a housing. The primary power input is configured to supply electrical energy to the electrically-powered system. However, the housing generally hampers access to the primary power input after installation of the appliance. Therefore, the auxiliary power input, which is also configured to supply electrical energy to the electrically-powered system, is readily accessible relative to the primary power input after installation of the appliance.

Abstract: A microcomputer includes a first switch coupled between a main power supply terminal and a power supply node, and a second switch coupled between an auxiliary power supply terminal and the power supply node. The microcomputer compares a voltage V1 of the main power supply terminal with a reference voltage VR1. When V1>VR1, the microcomputer turns on the first switch and turns off the second switch, and when V1<VR1, the microcomputer turns off the first switch, and turns on/off the second switch to gradually increase a voltage V3 of the power supply node. Thus, the operation of a clock generation circuit driven by V3 can be stable even when V3 is changed from V1 to V2.

Abstract: Devices and methods for electrically decoupling a solar module from a solar system are described. In one embodiment, a solar system includes a string of a plurality of solar modules coupled with an inverter through a DC power line. An AC input is coupled with the DC power line. A device is also included and is configured to provide a closed circuit for one of the plurality of solar modules if an AC signal voltage from the AC input is present on the DC power line, and is configured to provide an open circuit for the one of the plurality of solar modules if no AC signal voltage from the AC input is present on the DC power line.

Abstract: A power management apparatus and a method of operating the same are disclosed. The power management apparatus includes a power conversion unit, a first sensing unit, a second sensing unit, a switch unit, and a control unit. The power conversion unit converts output power generated from at least one renewable energy generation apparatus. The first sensing unit is provided to sense a first current and a first voltage and the second sensing unit is provided to sense a second current and a second voltage. The control unit acquires an output power generated from the renewable energy generation apparatus and acquires a feedback power to an AC utility according to the currents and the voltages when the control unit turns on the switch unit.

Abstract: A controller includes a difference detector that detects a difference between a switching timing of a first channel of a switching power supply including a plurality of channels, and a switching timing of a second channel of the switching power supply, the plurality of channels being coupled in common to an input power supply and performing switching operations in response to clock signals, and a timing adjuster that, based on a detection result of the difference detector, increases a difference between a timing of a clock signal supplied to the first channel and a timing of a clock signal supplied to the second channel when the difference between the switching timing of the first channel and the switching timing of the second channel is smaller than a first value.

Abstract: A method for controlling a power supply device for at least one electrical machine, having at least one storage device for electric energy (battery) and an inverter equipped with at least one reactor, the inverter having dual functions, being provided for charging (charge operation) the storage device from an in particular stationary power supply system, and for supplying the electrical machine with an alternating current in driving operation. A setpoint charge power is specified for the charge operation, and the reactor current is set accordingly by the inverter. Furthermore, a power supply device is also described.

Abstract: An output ripple voltage average amplitude of a switch mode DC-DC converter is dynamically maintained. The converter has a switch and an output filter. By varying a switching period (TPERIOD) of the switch, VRIPPLE is maintained at a substantially constant value over a first range of converter input voltages and a second range of switch duty cycles. Where the output filter includes an inductor having inductance (L) and a capacitor having capacitance (C) the average amplitude of VRIPPLE is dynamically maintained by varying TPERIOD with respect to switch duty cycle (D) and input voltage (VIN) so as to approximately satisfy the following relationship: TPERIOD=(VRIPPLE*8*L*C)0.5/(VIN*(D?D2)).5.

Abstract: An electric power transmitting apparatus and a method for controlling electric power transmission that switches a connection state of a coupling electrode in accordance with the shape and the size of an electric power receiving apparatus, a position where the electric power receiving apparatus is placed.

Abstract: A method is disclosed for producing electrical current by a fuel cell device, which inputs electrical current to an electrical network. A fuel cell device can be arranged to be parallel connected to the electrical network. A phase reference signal can be utilized in the inputting of the electrical current, and electrical current inputted to electrical network can be current controlled by a power transformer having a power stage. The fuel cell device can be switched off from the electrical network when a malfunction occurs in the electrical network. The fuel cell device can be changed, using the phase reference signal, to the switched off operation mode for performing voltage controlled operation of the power transformer. A controllable load can be used for maintaining a power stability between the voltage controlled power transformer and other parts of the fuel cell device.

Abstract: A Plug and Play adaptor for adding a PSU to a first PSU in a computer system. An ATX connector and a relay are contained in the adaptor. A second PSU can be added via the ATX connector in a plug-and-play manner, and the relay is energized and closes its circuit when it is powered by the first PSU and therefore turns on the second PSU through the ATX connector.

Abstract: A voltage regulator circuit for providing a regulated output voltage is provided. The voltage regulator circuit includes an error amplifier configured to provide a control signal based on at least a portion of a fed-back output voltage and a reference voltage. A first output stage is configured to operate at a first supply voltage and provide the regulated output voltage based on the control signal. At least one second output stage configured to operate at a second supply voltage different from the first supply voltage and provide the regulated output voltage based on the control signal. A switch-over unit is configured to switch over the control signal between the first output stage and the second output stage.

Abstract: A load control system for a building having a lighting load, a window, and a heating and cooling system comprises a lighting control device for controlling the amount of power delivered to the lighting load, a motorized window treatment comprising a window treatment fabric for covering the window, a temperature control device for controlling a setpoint temperature of the heating and cooling system to thus control a present temperature in the building, and a dynamic keypad comprising a visual display and operable to receive a user input. The dynamic keypad allows a user to select, adjust, and monitor a plurality of energy-savings modes of the load control system. For example, the dynamic keypad allows the user to enable and adjust a setback temperature of the temperature control device on-the-fly.

Abstract: A solar panel array comprises a first plurality of solar panels arranged side-by-side in a first course and a second plurality of solar panels arranged side-by-side in a second course, the second course partially overlapping the first course. Electrical energy produced by each solar panel of the array is aggregated with the electrical energy produced by the other solar panels of the array without physical electrical contacts between the solar panels. In one embodiment, contactless inductive couplers are used to couple the electrical energies of the panels together.

Abstract: A polyphase power management system (PMS) and a method of operating the same. In one embodiment, the PMS includes: (1) a switching unit having a polyphase mains input with a neutral, a backup power input, a rectifier output and an other loads output, (2) a mains monitor/controller coupled to the switching unit and configured to monitor the polyphase mains input and route various phases of the polyphase mains input or the backup power input to the rectifier output and the other loads output based on the number of phases that are nominal at the polyphase mains input.

Abstract: A protection method in a distributed power system including of DC power sources and multiple power modules which include inputs coupled to the DC power sources. The power modules include outputs coupled in series with one or more other power modules to form a serial string. An inverter is coupled to the serial string. The inverter converts power input from the string and produces output power. When the inverter stops production of the output power, each of the power modules is shut down and thereby the power input to the inverter is ceased.

Abstract: The invention relates to a standalone unit for a standalone power grid, to a standalone power grid comprising a standalone unit and to a method for controlling a standalone power grid. In order to permit reduced recourse to an external power grid or public power grid, the standalone unit according to the invention comprises a power generation unit, in particular a photovoltaic unit, for generating power from renewable resources, an energy storage unit for storing energy, a load connection unit for connecting the standalone unit to a load unit for consuming energy, a grid unit, in particular an inverter unit, for connecting the standalone unit to a power grid, for drawing energy from the power grid and for feeding energy into the power grid, and an interface unit for communicating an energy withdrawal request and/or an energy storage request with a second standalone unit.

Abstract: A power regulation system for an electrical grid has a store of electrical energy connected through a first switch to a source of electrical energy. The response time of the store is faster than that of the source. A second switch is connected to the store at one side with the opposite side for connection to the grid. A first controller monitors energy stored in the store and energy available from said source and selectively controls the first switch to close to transfer energy from the source to the store. A second controller monitors energy stored in said store and, on receiving an indication that additional energy is needed in the grid, if the energy stored in the store exceeds a supply threshold, controls the second switch to close to transfer energy from the store to the grid.

Abstract: A power integrated circuit includes, in part, a multitude of controllers, a multitude of pulse-width generators, a multitude of output stages and a configuration matrix. Each controller is adapted to be responsive to a feedback signal and a reference signal to generate a control signal carrying pulse width information. Each control signal causes a difference between an associated output voltage feedback signal and the reference signal to be less than a predefined value. Each pulse-width generator is associated with and responsive to a different one of the controllers to generate a pulse-width modulated signal in response. The configuration matrix selectively couples the plurality of pulse-width generators to the output stages.

Abstract: A multiplexer includes: a first switch unit coupled between a first input terminal and an output terminal and including a series connection of first and second switches; a second switch unit coupled between a second input terminal and the output terminal; and a third switch unit coupled to a third input terminal and a common node between the first and second switches. Different first and second voltages, and a third voltage greater than one of the first and second voltages and less than the other one of the first and second voltage are applied respectively to the first, second and third input terminals. The multiplexer is operable between a first mode, where the first voltage is transmitted to the output terminal, and a second mode, where the second voltage is transmitted to the output terminal and the third voltage is transmitted to the common node between the first and second switches.

Abstract: A current generator is disclosed. An example current generator includes a plurality of current cells connected in parallel, each current cell being connected to a switch. The current generator further includes a first summer configured to sum the output of each current cell of a first subset of the plurality of current cells and a second summer configured to sum the output of each current cell of a second subset of the plurality of current cells. The current generator also includes a combiner configured to combine the outputs of the first and second summers. Further, each switch is switchable according to a sequence to generate a summed output of the current cells at a plurality of quantization levels to generate positive and/or negative alternations of a pseudo-sinusoidal, alternating current.

Abstract: The invention discloses a computer and an expandable power supply system. The expandable power supply system includes N interface units, a determination unit, and a voltage converting unit. N is an integer equal to or more than two. The interface units are electrically connected with at least one power supplies and switching the levels of (N?1) control signals according to conductance of the power supplies. When the interface units are electrically connected with 1st to Mth power supplies, the determination unit outputs a start signal when the determination unit receives power reply signals provided by the 1st to Mth power supplies. M is an integer, and 1?M?N. The voltage converting unit is enabled according to the start signal to distribute operation voltages provided by the 1st to Mth power supplies by utilizing the control signals to generate a supply voltage.

Abstract: A plurality of sodium-sulfur batteries are divided into a plurality of groups. Power to be input or output, which is assigned to all sodium-sulfur batteries in order to compensate for fluctuations of output power of a power generation device, is distributed to each group. The plurality of sodium-sulfur batteries divided in the groups are periodically rotated. This enables a uniform utilization rate of the sodium-sulfur batteries to be achieved.

Abstract: A switching assembly includes a first terminal and a second terminal, a first switch connected to the first terminal, and a second switch connected to the second terminal. The switching assembly further includes a rectifier bridge connected between the first switch and the second switch, and a third switch connected between the first terminal and the second terminal. The switching assembly also includes a control unit that selectively opens and closes the first switch, the second switch and the third switch, and selectively turns on and off the rectifier bridge.

Abstract: A system for supplying an electrical system with direct current, the system including at least two direct current power supply devices each having means of electrical connection to an alternating current power supply source and an AC/DC converter of alternating current into direct current, a module for managing the power supply of the electrical system which, after reception of an information of failure of a first active power supply device, transmits a command to start up a second inactive power supply device and a back up electrical energy storage device electrically by-pass connected between the power supply devices and the electrical system. The management module also receives the information of failure from the back up device and/or from the electrical system and transmits the command to start up the second power supply device during a discharge phase of the back up device.

Abstract: A standardized system, method and apparatus for connection of any combination of electric energy supply source including the Utility Power Grid, Auxiliary Generator, Wind Turbine, Fuel Cell, Storage Battery, Solar Panel Array, and an Electric Car which are collectively aggregated to feed into the main Service Panel of the Home or Small Business through a single plug-in connection to the Home or Small Business's electrical service entrance and provide for collective operational monitoring and management through an IP Networked Communication Link, commonly referred to as IP Networked Communication across the Internet, thereby providing bidirectional communication and control between the GTC and the Smart Load Management functionality resident on the Internet Cloud.

Abstract: A multiple power supply device including a power consuming unit, a plurality of power supply units, and a plurality of switching units is provided. The power consuming unit receives a plurality of power good signals, and outputs a plurality of power control signals accordingly. The power supply units output a plurality of working voltages respectively, and meanwhile output the power good signals. When the power consuming unit is in a working state and one of the power good signals is enabled, the power consuming unit enables the corresponding power control signal. When the power consuming unit is in a working state and a part of the power good signals are enabled, the power consuming unit enables one of the power control signals corresponding to the enabled power good signals. The switching units transmit the corresponding working voltage to the power consuming unit according to the enabled power control signal.

Abstract: Some embodiments relate to an example power management system. The power management system includes a first enclosure and a second enclosure. A first generator is inside the first enclosure and a second generator is inside the second enclosure. The power management system further includes a paralleling enclosure and a paralleling module inside the paralleling enclosure. The paralleling module includes at least one switching device within the paralleling enclosure to electrically connect the first generator to the second generator. The paralleling enclosure further includes a plurality of connectors that permit electrical connection between the paralleling module and the first generator, the second generator and an output without opening the paralleling enclosure.

Abstract: We describe a photovoltaic power conditioning unit for delivering power from multiple photovoltaic panels to an ac mains power supply output, comprising: a dc input for receiving power from multiple photovoltaic panels; an ac output for delivering ac power to the ac supply; a bank of electrolytic energy storage capacitors for storing energy from the dc source for delivery to the ac supply; a dc-to-ac converter coupled to the ac output and having an input coupled to the bank for converting energy stored in the bank to ac power for the ac supply; and further comprising: a plurality of sense and control circuits, one for each capacitor in the bank, wherein each circuit is coupled in series with a capacitor, and is configured to disconnect the associated capacitor from the bank upon detection of a current flow thorough the associated capacitor of greater than a threshold current value.

Abstract: A power switching device, a power switching method, and a projection device using the power switching device are provided. In the power switching method, a first power and a second power are received, and the voltage level of the first power is compared with the voltage level of the second power. One of the first power and the second power having the higher voltage level is sustained by using one of the first power and the second power having the lower voltage level until one of the first power and the second power having the higher voltage level stabilizes. At least one of the first power and the second power having the higher voltage level and being already stabilized is output as an output voltage.

Abstract: A power distribution system is described that does not rely on a fixed frequency and which therefore allows prime movers to run at different speeds in response to load demand, typically so that fuel consumption and/or harmful exhaust emissions is/are minimised. A marine power distribution and propulsion system can include an ac busbar adapted to carry a variable-frequency ac distribution voltage. A plurality of ac generators are connected to the busbar, each having an associated prime mover such as a diesel engine, turbine etc. A power management controller is adapted to vary the rotational speed of the prime movers with reference to the electrical load on the ac busbar such that the generators provide a variable frequency output during normal operation of the power distribution system. Such operation is to be contrasted with conventional distribution systems which have a fixed frequency.

Abstract: A power supply system includes a main power storage device and a plurality of sub power storage devices. A converter is sequentially connected to one of the sub power storage devices to convert voltage between the selected sub power storage device and an electric power feeding line bidirectionally. The sub power storage device undergoes a connection switching process, and when there is no new sub power storage device remaining for replacement, then, in accordance with that sub power storage device's SOC and the vehicle's state, a request is generated to disconnect the sub power storage device. Here, when a condition regarding a temperature of at least one of the main power storage device and the plurality of sub power storage devices is satisfied, generation of a disconnection request is prohibited, in order to protect the main power storage device.

Abstract: A power switching circuit is connected to an external power source, a battery, and a load. The power switching circuit includes a voltage converter, a prevention unit, a detecting unit, and a switch. The voltage converter converts a first primary voltage supplied by the external power source to a secondary voltage. The prevention unit allows the secondary voltage to be transmitted to the load, the secondary voltage powering the load. The detecting unit generates a first level signal when the external power source fails to output the first primary voltage. The switch is turned on to transmit a second primary voltage supplied by the battery to the load and the prevention unit in response to the first level signal. The second primary voltage powers the load. The prevention unit prevents the second primary voltage from being transmitted to the voltage converter.

Abstract: One embodiment of an integrated circuit includes a local circuit block, a first power supply for supplying power to a first terminal of the local circuit block, a second power supply for supplying power to a second terminal of the local circuit block, a first transmission gate coupled between the second terminal of the local circuit block and a current path from the second power supply, and a second transmission gate coupled between the current path from the second power supply and a gate of a p-type metal-oxide-semiconductor (PMOS) transistor in the first transmission gate, the second transmission gate including a single transistor.

Abstract: In an aspect, a battery assembly is adapted to accommodate a plurality of unit cells, the battery assembly has: a unit cell wiring configured to provide at least one connection for the unit cells; a cut-off device having a fuse circuit and a heater circuit, the fuse circuit configured to disconnect the connection by heat produced in the heater circuit; and a power supply wiring configured to supply the heater circuit of the cut-off device with an electric power.

Abstract: A method for power management of a multi-cell battery includes identifying a desired power value and voltage value, determining a battery voltage value and a battery current value for a battery, determining a number of battery banks from a plurality of battery banks to use for the battery, where each battery bank includes one or more battery cells (or battery modules), checking availability of each of the one or more battery cells (or battery modules), selecting one or more battery banks from the plurality of battery banks, where the selection of a battery bank is based on the availability of the battery cells (or battery modules) included in the battery pack, and a quantity of the selected battery banks is equal to the determined number of battery banks, and connecting the available battery cells (or battery modules) in the selected one or more battery banks to form the battery.

Abstract: The disclosure relates to methods for sequentially disconnecting at least two electrical current sources from a common load or for sequentially connecting the current sources to a load, wherein the current sources are each connected to the common load via a switching unit, each comprising a parallel circuit comprising an electromechanically actuated switch and an associated semiconductor switch. In the two methods, first semiconductor switches are closed if they are still not closed and the relevant electromechanical switches are opened. In the method for sequential disconnection, then at least two of the semiconductor switches that were actuated or that were already closed are opened sequentially. In the method for sequential connection, a plurality of the semiconductor switches are first opened, of which then at least two are closed sequentially. The disclosure also relates to a photovoltaic system comprising an apparatus that is suitable for implementing the method.

Abstract: A system and method that offers the provision too rapidly and safely connect electrical generation sources, including inverters used by solar collecting panels, or wind turbines, and backup hydrocarbon fueled generators or any other supplemental power sources including storage batteries, fuel cells and future electric automobiles. Thus enabling the feeding of power to all circuits in the home or small business, not just isolated circuits in a structure. The system is compliant with electric codes, requires no costly rewiring inside the structure or in the electrical circuit panel and can be accomplished entirely from the outside of the home or small business adjacent to the electric service meter for the home or small business structure.

Abstract: One aspect of the present invention can include a playback device capable of externally receiving a playback signal for playing back a sound or an image, and capable of transmitting the playback signal to the playback device if it is detected that a predetermined electric source was externally supplied.

Abstract: A power supply device includes a battery, positive and negative-side contactors and a controller. The battery supplies power to a load. The positive-side contactor is serially connected to the positive side of the battery, and the negative-side contactor is serially connected to the negative side of the battery. The controller determines whether the load connected to the output sides of the positive-side contactor and the negative-side contactor is in a connected or non-contact state. The controller includes a voltage detecting circuit that detects the capacitor voltage of a capacitor connected to the output sides of the positive-side contactor and the negative-side contactor, and a determination circuit that compares the detected voltage with a predetermined voltage and determines the connected state of the load.

Abstract: The present invention relates to a wind turbine facility power supplying arrangement for supplying electrical power to at least a switchgear being able to isolate the wind turbine facility from an electrical network, the wind turbine facility power supplying arrangement comprising a first electrical power supply path able to be provide electrical power to the switchgear and a first power switch able to break said first electrical supply path and able to be controlled for opening and closing. The wind turbine facility power supplying arrangement contains at least another parallel electrical power supply path able to provide electrical power to the switchgear, said parallel electrical supply path been breakable with at least another respective parallel power switch, said parallel power switch being controllable for opening and closing.

Abstract: Systems and methods of voltage based switching of a power supply system current are disclosed. In one embodiment, a power supply system includes a power bus to supply electrical power to a system load. A power supply is coupled to the power bus. The power supply provides current to the power bus and generates a voltage ?. In addition, the system includes an additional power supply coupled to the power bus. The additional power supply generates a voltage ? that is lower than the voltage ?. An oring module restricts the additional power supply from providing current to the power bus, until a power bus voltage ? is greater than a threshold voltage.

Abstract: A system and method for supplying power to a variable speed motor for rotating a shaft may include generating an A/C output having a variable frequency corresponding to speed of a prime mover, where the speed of the prime mover is equal to or greater than a predetermined speed limit. The A/C output of the prime mover may be distributed to the variable speed motor such that the speed of the variable speed motor is varied relative to the frequency of the A/C output. The variable speed motor may be electrically disconnected from the A/C power when the speed of the prime mover being used to drive the variable speed motor is equal to or within a predetermined range of the predetermined speed limit. An alternate A/C output may be distributed to the variable speed motor after the A/C power is electrically disconnected from the variable speed motor.