Abstract: Electric components for controlling the delivery of electricity from an electrical grid to an electric vehicle, the arrangement having a first, a second, a third, and a fourth input terminals, each for receiving an electric signal from the electrical grid. The arrangement also includes two switching components for controlling two connections between a neutral output terminal connectable to the electric vehicle and the first and the second input terminals. Moreover, the arrangement includes three switching components for controlling three connections between a first-phase output terminal connectable to the electric vehicle and the second, the third, and the fourth input terminals.

Abstract: A method of powering a controller using an intermediate device with power from an environmental system may include receiving current from a power wire from the environmental system; passing the current from the power wire to a second command wire from the controller; monitoring the current flowing between the power wire and the second command wire while the current is below a threshold indicative of an amount of current used to power the controller from the environmental system; detecting when the current flowing between the power wire and the second command wire exceeds the threshold indicating that the controller is sending a command to the environmental system to perform the function; and sending a command to environmental system using a first command wire from the environmental system after detecting that the current exceeds the threshold.

Abstract: A sensor apparatus includes a photosensitive sensor, a cover, and a moving mechanism. The photosensitive sensor includes a first lens and a second lens which focus on a photosensitive element. The cover includes a first slit arranged on an optical axis of the first lens and a second slit arranged on an optical axis of the second lens. The moving mechanism is configured to move the photosensitive sensor and the cover relative to each other so that the second slit is arranged on the optical axis of the first lens.

Abstract: The present invention relates to a method for power balancing a power grid (10) having multiple phases (12:1,2 3) and a common ground (0). The power grid (10) is connected to at least one load (13, 17) causing a non-uniform power consumption between the multiple phases (12: 1, 2, 3) of the power grid (10). The method comprises: monitoring power provided to the power grid (10) in controller (18), storing available energy in the power grid (10) in an energy storage (16) using multiple inverters (I1, I2, I3), each inverter (I1, I2, I3) is connected between the energy storage (16) and each phase (12: 1, 2, 3) of the power grid (10), and redistributing power between phases (12: 1, 2, 3) based on power available in the energy storage (16) by controlling power flow through the inverters (I1, I2, I3) by the controller (18) based on the non-uniform power consumption.

Abstract: A supply-demand control device is configured to: set, for each priority rank defined in advance, an allowable limit within a range of a value set for a higher priority rank than the each priority rank, the allowable limit indicating an upper limit of the power or the energy allowed to be supplied in response to a demand of the each priority rank while the power or the energy supplied in response to a demand of the higher priority rank is secured; detect the demand for the power or the energy, which occurs in the industrial product; and allocate, in order of the priority rank, the power or the energy supplied from a predetermined supply source in response to the detected demand, such that the supplied power or energy is equal to or lower than the upper limit indicated by the allowable limit set for the each priority rank.

Abstract: A lighting test method that includes connecting a housing including driver electronics and a junction box to a main power source. The main power source is connected to a main power connector in the junction box. The driver electronics includes a first terminal. The method further includes connecting a power testing module to the first terminal to the driver electronics to determine whether the main power source is correctly connected to the main power connector in the junction box. The method further includes replacing the power testing module with a second terminal of a light engine housing. Connecting the first and second terminals provides that the driver electronics are in electrical communication with a light engine within the light engine housing.

Abstract: A solar power system and method of operation includes a solar array, a plurality of loads electrically coupled in parallel to the solar array, and a control circuit electrically coupled to the solar array and in communication with the loads. The control circuit is configured to cause the solar array to operate at a maximum power point (MPP), prioritize power requirements of the loads, and variably allocate power from the solar array among the loads according to the prioritized power requirements of the loads.

Abstract: A driving protection circuit is coupled to a load via an input/output pin. A signal generator circuit is configured to generate a driving signal. An input/output circuit transmits the driving signal to the input/output pin according to an enable signal. A counter circuit adjusts the count value when the enable signal is at a predetermined level. A detection circuit detects the voltage level of the input/output pin to generate a detection signal. When the count value is equal to a predetermined value, a control circuit determines whether the level of the detection signal is the same as the level of the driving signal. When the level of the detection signal is not the same as the level of the driving signal, the control circuit sends an error signal to turn off power to the load.

Abstract: A method for controlling a power strip includes: acquiring a present temperature parameter of an ambient environment; determining a presently-allowed maximum power of the power strip based on the present temperature parameter; acquiring a total power of electronic devices presently powered by the power strip; and controlling the power strip to cut off power supply to at least one of the electronic devices when the total power is greater than the presently-allowed maximum power. In the technical solution, the presently-allowed maximum power of the power strip can be adjusted automatically based on the present temperature parameter of the ambient environment of the power strip, which improves flexibility of adjusting the maximum power.

Abstract: A multi-output power supply device includes an inductor, a first output terminal, a second output terminal, an FET, an FET, a chopper circuit, and a controller. The FET adjusts a current output from the inductor to the first output terminal. The FET adjusts a current output from the inductor to the second output terminal. The chopper circuit has the FET and the inductor. The FET is connected in parallel with the FET, and conducts or cuts off a current. The inductor is provided between the FET and the second output terminal. For example, the controller lowers a potential from the first output terminal by turning on the FET and sets a potential difference between a drain terminal and a source terminal of the FET to zero to suppress a switching loss when the FET is turned on.

Abstract: A method and apparatus for controlling the load presented to one or more power sources such as a power grid, backup power generator or solar panel is described. By selectively connecting, disconnecting, limiting and controlling various loads which are powered, the power grid service connection and power sources may be economically sized and operated while allowing reliability and convenience in selecting and powering loads. The control of the loads connected to the power sources is prioritized by various parameters including the power source operation parameters including load handling capability, type of load, load size, environmental factors, load usage during and subsequent to load connection, load priority and operator wishes. The control may also operate to facilitate transfer of power from one power source or load to another power source or load.

Abstract: In the present invention, the connection between an external power supply and a unit for detecting welding of a relay is disestablished at least when a short circuit is detected, thereby preventing the short circuit from being falsely detected in the event that the short circuit and the welding of the relay can both be detected. A device for detecting welding of a relay detects welding of a relay provided to a path via which a cell is charged by an external power supply. Welding of a power-supply-side relay or a ground-side relay is detected on the basis of a current flowing disproportionately more toward the external power supply than the power-supply-side relay or ground-side relay when a control unit has deactivated the power-supply-side relay or ground-side relay during an interrupting in charging. A disconnecting switch establishes or disestablishes the connection between the external power supply and a weld-detection switch.

Abstract: A furniture electrical system includes an electrical power unit including a housing that is mountable to a furniture article and that defines an interior cavity, with a low voltage DC electrical outlet positioned in the interior cavity. An electrical power cord is in electrical communication with the electrical outlet and exits the housing, the power cord extending to a higher voltage DC power supply associated with an electric motor for raising and lowering a furniture article. An electrical power converter in the housing reduces the voltage from the higher voltage DC power supply to the low voltage DC electrical outlet. Optionally, an indicia lamp associated with each outlet illuminates at a first luminous intensity when the outlet is energized, and illuminates at a different second luminous intensity when the outlet is energized and supplying power to an electrical power consumer.

Abstract: A clamp logic circuit has a logic circuit, a control terminal, a current clamp circuit and an output terminal. The logic circuit has at least a junction field-effect transistor (JFET). The control terminal receives an input signal. The current clamp circuit has a transistor and a resistor. A first end of the transistor is coupled to the control terminal, a second end of the transistor is coupled to a first end of the resistor, a control end of the transistor is coupled to a reference voltage, and a second end of the resistor is coupled to an input end of the logic circuit. The output terminal is coupled to an output end of the logic circuit.

Abstract: An LED luminaire comprises a rechargeable battery, LED array(s), two drivers, and a power outage detection circuit. The LED luminaire may be used to replace a conventional lamp connected to AC mains for use in emergency. The two drivers comprise a first driver configured to operate the LED array(s) and to manage to charge the rechargeable battery when the line voltage from the AC mains is available and a second driver configured to convert a terminal voltage from the rechargeable battery into a DC voltage to power the LED array(s) when a line voltage from the AC mains is unavailable. The power outage detection circuit is configured to enable or disable the second driver in proper situations and to meet regulatory requirements without operational ambiguity and safety issues. Furthermore, the first driver comprises a controllable current shunt circuit configured to regulate a charging current to flow into the rechargeable battery.

Abstract: A method is provided for power limiting in a power inverter configured to produce an output voltage and having a voltage regulator with a voltage setpoint defined for no load on an external bus line. The method includes determining a power level related to a load on the external bus line, determining an adjusted voltage setpoint based on the power level, including: decreasing the voltage setpoint to the adjusted voltage setpoint having a first value when the power level is above a maximum threshold, increasing the voltage setpoint to the adjusted voltage setpoint having a second value when the power level is below a minimum threshold, and slewing the adjusted voltage setpoint to the voltage setpoint so that the adjusted voltage setpoint has a third value when the power level is within a range defined by the maximum threshold and the minimum threshold.

Abstract: In one embodiment, a circuit includes a plurality of elementary transistors connected in parallel between a node of application of a first potential of a power supply voltage and a node for coupling a load. The plurality of transistors includes a first assembly of elementary transistors having their gates coupled to a control node by a first circuit and a second assembly of elementary transistors having their gates coupled to the control node by a second circuit. The second circuit has two states, where the first and second circuits are configured to supply a substantially identical control voltage to the gates of the first and second assemblies of elementary transistors when the second circuit is in one of the two states.

Abstract: A camera for a vehicular vision system includes a housing and a lens barrel including a lens. The camera is configured to be disposed at an exterior portion of a vehicle so as to have a field of view exterior of the vehicle. A heating device is disposed at an exterior of the lens barrel. The heating device includes a thin foil heating element that at least partially circumscribes the lens barrel. The heating device includes an electrical lead that is configured to electrically connect to an electrical connector of the vehicle when the camera is disposed at the exterior portion of the vehicle.

Abstract: A method and apparatus for power allocation across multiple loads. The method comprising the steps of: allocating available power between two or more power load elements, wherein a ratio of power allocated to a load element is based on a priority and measured parameters; and dynamically updating the power allocated to a load element as power requirements change.

Abstract: The invention discloses a power saving device capable of automatically sensing standby current, which is used in a power device such as a power outlet or other power supply devices for giving the power device ability of electricity saving. When the power saving device normally works, a threshold current setting unit of a controlling and processing module is configured to automatically calculate a threshold current based on current signals sensed by a current detecting unit under different operation modes of at least one electrical device electrically connected to the power device. Moreover, when at least one standby current sensed from the electrical device is determined to be lower than the threshold current, the controlling and processing module immediately switches a switch unit to an open-circuit state, thereby causing the electrical device unable to receive electricity from the power device. Consequently, the power device exhibits the ability of power saving.

Abstract: Interface circuitry is provided for a host device, the interface circuitry for controlling data connections between the host device and a peripheral device.

Abstract: An assembly, system, and method for receiving, distributing, and monitoring electrical power received from one or more sources is characterized by a residential electrical panel having at least a main bus panel having one or more house load circuit breakers, a main circuit breaker, a first meter, and a battery output; a second bus panel having a battery input communicatively connected to the residential electrical panel and one or more critical load circuit breakers; one or more jumpers communicatively connecting the main bus panel to the second bus panel; a second meter communicatively connected to the monitoring device; a solar sub panel communicatively connected to the second meter; and a monitoring device communicatively connected to the residential panel, the solar sub panel, the second bus bar, and the second meter.

Abstract: Example implementations relate to selectively enabling backup power to nodes. For example, a system includes a plurality of compute nodes, where each node includes a plurality of loads. The system also includes at least one backup power supply and control module coupled to the nodes and to the at least one backup power supply. The control module is to selectively enable an output of power from the at least one backup power supply to the nodes based on a comparison of a power capacity of the at least one backup power supply and a backup power demand of the nodes.

Abstract: A system and/or method is provided that manages delivery of power for a device and an additional device. The system can include a device that consumes power to refrigerate an item stored therein, wherein the device includes an eutectic plate and an additional device that consumes power. The system can further include a power source that is configured to deliver power and a power manager component that is configured to monitor a temperature within the device. The power manager component can further be configured to activate the power source to deliver power to the device to reach a set temperature, switch the delivery of power from the device to the additional device based on the set temperature being reached, and maintain the set temperature in the device by switching delivery of power from the additional device to the device based on monitoring the temperature.

Abstract: A system for electrically operating a circuit breaker remotely and during period of a power outage is provided. The system has a power source, power cable, control unit, control device, and a circuit breaker port for connecting the power source and control unit to the circuit breaker, for actuation of the circuit breaker operating mechanism.

Abstract: A power control device for use in an AC power grid for regulating an electrical power a load that is supplied by the AC power grid consumes. The power control device has a frequency sensing functional block for detecting a rate of deviation of the grid frequency from a nominal grid frequency and a logic functional block for performing a load shedding process during which the power the load consumes is reduced. The load shedding process is characterized by parameters, the logic functional block controlling one or more parameters of the load shedding process at least in part on the basis of the rate of deviation of the grid frequency.

Abstract: A PCB motor controller comprises relays mounted on a PCB and interconnected to power traces in or on the PCB to receive incoming three-phase power and to output three-phase power to a motor. Control power traces in or on the PCB connect the relays to control circuitry, also mounted on the PCB. A power supply is mounted on the PCB and connected to the control circuitry to provide power for its operation and for switching of the relays. The relays are switched in accordance with a point-on-wave (POW) switching scheme, allowing for the use or relays and the PCB, which may not otherwise be suitable for motor control applications.

Abstract: A PCB motor controller comprises relays mounted on a PCB and interconnected to power traces in or on the PCB to receive incoming three-phase power and to output three-phase power to a motor. Control power traces in or on the PCB connect the relays to control circuitry, also mounted on the PCB. A power supply is mounted on the PCB and connected to the control circuitry to provide power for its operation and for switching of the relays. The relays are switched in accordance with a point-on-wave (POW) switching scheme, allowing for the use or relays and the PCB, which may not otherwise be suitable for motor control applications.

Abstract: A PCB motor controller comprises relays mounted on a PCB and interconnected to power traces in or on the PCB to receive incoming three-phase power and to output three-phase power to a motor. Control power traces in or on the PCB connect the relays to control circuitry, also mounted on the PCB. A power supply is mounted on the PCB and connected to the control circuitry to provide power for its operation and for switching of the relays. The relays are switched in accordance with a point-on-wave (POW) switching scheme, allowing for the use or relays and the PCB, which may not otherwise be suitable for motor control applications.

Abstract: A first battery pack includes a first battery module and a first controller. A second battery pack includes a second battery module and a second controller. The first battery pack and the second battery pack are installed to be freely attachable and detachable in relation to a main body. An activation manager performs an activation instruction such that the first controller and the second controller do not activate at a same timing. The first controller which activates earlier operates in an ordinary mode in which power is supplied from the first battery module to an AC load. The second controller which activates later operates in a standby mode in which power is not supplied from the second battery module to the AC load.

Abstract: A utility is distributed to a group of subscribers via a distribution network. At least one parameter reflecting an instantaneous overall consumption of the utility in the distribution network is measured repeatedly, and an amount of the utility delivered to each subscriber in the group is controlled in response thereto. It is checked whether the instantaneous overall consumption of the utility is within an acceptable interval. If it is below a lower threshold level, at least one load is controlled to increase its consumption of the utility according to a pre-defined scheme in proportion to a deviation of the instantaneous overall consumption of the utility from the lower threshold level. If it is above an upper threshold level, at least one load is controlled to decrease its consumption of the utility according to the pre-defined scheme in proportion to a deviation of the overall consumption of the utility from the upper threshold level.

Abstract: In an example, a circuit for controlling at least two electronic switches in a parallel configuration between a power supply and a load. The circuit includes a control circuit to generate first and second control signals to control first and second electronic switches of the at least two electronic switches, and establish a conduction sequence of the first and second electronic switches using the first and second control signals. The circuit includes a detection circuit configured to detect a current flowing through a control terminal of the first electronic switch during a transition portion, wherein the circuit is configured to adjust the first control signal and establish the second portion of the conduction sequence in response to the detected current.

Abstract: Quickly USB Charging ports for lighted cosmetic mirror related device has mirror, or reflective surface, or magnify kits has USB charging-ports which meet 2007 released specification has minimum 1.0 Amp to 5 Amp at DC 5 Volt range for charging capacity to quickly charge DC current into energy-storage unit or assembly inside the other electric or digital product(s) and, optionally, additional outlet-units, to supply AC current to other electric or digital devices including smart phone, computer, communication, consumer electric products, people cosmetic kits or tools or equipment. The USB-unit(s) or USB-Module(s) or Outlet-unit(s) fit within or install on anywhere of the device's housing including anywhere of the base, housing, walls. The said USB charger only has charging function no any data transmit and only have one input power source not more than one and charging capacity minimum 1.0 Amp to 5.

Abstract: Power receptacle control circuitry includes load switching circuitry, communications circuitry, sensor circuitry, processing circuitry, and a memory. The sensor circuitry includes a light sensor. The processing circuitry is coupled to the load switching circuitry, the communications circuitry, the sensor circuitry, and the memory. The memory includes instructions, which, when executed by the processing circuitry cause the power receptacle control circuitry to selectively deliver power to a load via the load switching circuitry, detect a modulated light signal via the light sensor, and join a group of devices based on the modulated light signal.

Abstract: A thermostat method and apparatus has one or more demand circuits, an energy storage device; a DC regulator connected to the energy storage device, and a thermostat control connected to the DC regulator and to the energy storage device. Current is drawn from the one or more demand circuits when demand associated with the demand circuits is not active and the energy storage device is charged with the current drawn from the one or more demand circuits. If energy stored in the energy storage device is below the first predetermined threshold, activity in the thermostat is reduced and if energy stored in the energy storage device is above the second predetermined threshold, activity in the thermostat is allowed to increase.

Abstract: An example device includes a processor configured to receive a plurality of voltage measurements corresponding to nodes in a distribution network, and determine, for each respective node: a value of a first coefficient, based on a previous value of the first coefficient, a minimum voltage value for the node, and a voltage measurement that corresponds to the node, and a value of a second coefficient based on a previous value of the second coefficient, a maximum voltage value for the node, and the voltage measurement. The processor of the example device is also configured to cause an inverter-interfaced energy resource connected to the distribution network to modify its output power based on the value of the first coefficient for each node and the value of the second coefficient for each node.

Abstract: A method for managing an energy consuming load in a group of energy consuming loads and a method for managing the group of energy consuming loads. The method includes generating sets of load state data from the loads, making enablement state decisions for one or more loads using the sets of load state data, and implementing the enablement state decisions. Each of the enablement state decisions reflects an enablement state of a load, wherein the enablement state is either a load enabled state where the load is capable of operating even when the load is not actually operating or a load disabled state where the load is not capable of operating. A computer readable medium may include computer readable instructions for directing a processor to perform the methods and make the enablement state decision. Further, an apparatus comprised of a processor may be programmed to perform the methods.

Abstract: In a frequency control system, a system controller assigns load-specific threshold frequencies to electrical loads of a fleet of electrical loads. Load controllers perform load monitoring and control operations for controlled electrical loads of the fleet including (i) comparing a measurement of the electrical frequency with the threshold frequency assigned to the controlled electrical load and (ii) operating the controlled electrical load based on the comparison. For example, each load controller may perform operation (ii) by turning the controlled electrical load on if the measurement of the electrical frequency is greater than the threshold frequency assigned to the controlled electrical load, and turning the controlled electrical load off if the measurement of the electrical frequency is less than the threshold frequency assigned to the controlled electrical load. The threshold frequencies may be assigned based on State of Charge (SOC) values for the loads.

Abstract: In the present invention, the connection between an external power supply and a unit for detecting welding of a relay is disestablished at least when a short circuit is detected, thereby preventing the short circuit from being falsely detected in the event that the short circuit and the welding of the relay can both be detected. A device for detecting welding of a relay detects welding of a relay provided to a path via which a cell is charged by an external power supply. Welding of a power-supply-side relay or a ground-side relay is detected on the basis of a current flowing disproportionately more toward the external power supply than the power-supply-side relay or ground-side relay when a control unit has deactivated the power-supply-side relay or ground-side relay during an interrupting in charging. A disconnecting switch establishes or disestablishes the connection between the external power supply and a weld-detection switch.

Abstract: A power switching system, a method, and an information handling system (IHS) enables selective activation and de-activation of respective alternating current (AC) outlets of a plurality of AC outlets within an AC switch (ACS). The AC switch includes a decoder circuit that is couple via a control interface to a management controller (MC) and receives control commands from the control interface. In response to receipt of the control command, the decoder circuit decodes the command in order to provide control signals to one or more of a number of serial voltage relays, which are each respectively coupled to the AC outlets. The AC switch utilizes the decoder circuit to respectively configure the serial voltage relays using the control signals. By configuring the serial voltage relays, the MC provides and/or removes respective connections between AC inputs and AC outlets, which selectively activates and/or de-activates respective AC outlets.

Abstract: A method of harvesting power from a heating, ventilation, and air conditioning (HVAC) system using an HVAC controller may include harvesting power from the HVAC system and measuring an electrical characteristic of the HVAC controller. The electrical characteristic may indicate whether the power harvested from the HVAC system is high enough to risk interfering with a normal operation of the HVAC system. The method may also include increasing the power harvested from the HVAC system until the electrical characteristic indicates that the HVAC controller is at risk of interfering with the normal operation of the HVAC system.

Abstract: A method is used in a utility meter having an arm bit and a seal bit. The method includes changing a state of the arm bit to a first state in response to a first set of conditions. The method also includes removing electrical power from the meter. Upon subsequently applying electrical power to the meter, a first signal in a meter processing circuit indicates whether a meter cover is installed or the meter cover is removed. The processing circuit changes the seal bit to a first state responsive to a condition in which the arm bit is in the first state and the first signal indicates that the meter cover is installed. The processing circuit changes the seal bit to a second state responsive to a condition in which the seal bit is in the first state and the first signal indicates that the meter cover is removed.

Abstract: A system and method of controlling the data transfer rate of a switching power converter when the switching frequency is below a desired level by using an auxiliary load to at least maintain output regulation.

Abstract: An electrical system having a plurality of devices is supplied with power by a common power supply line. One of the devices has a circuit that slows or delays device startup or activation in response to a signal indicative of power demand, draw or use by another of the plurality of devices supplied with power by the common power supply line.

Abstract: Examples described herein relate to circuit breaker reset for power distribution units (PDUs). In one example, an apparatus to reset a circuit breaker of a PDU includes a bracket to enclose a portion of a rack rail, where one end of the bracket is coupled to a surface of the PDU including the circuit breaker. The apparatus also includes an elongated member disposed within the bracket, the elongated member includes a distal end to make contact with the circuit breaker, when force is applied to a proximal end of the elongated member, to reset the circuit breaker.

Abstract: In a thermal protection circuit with two electrical connection terminals for an electrical device to be protected from overheating and at least one temperature-dependent switch, at least one electronic semiconductor switch for DC voltage is arranged.

Abstract: Disclosed herein are a variety of systems and methods for management of an electric power generation and distribution system. According to various embodiments, a system consistent with the present disclosure may be configured to analyze a data set comprising a plurality of generator performance characteristics of a generator at a plurality of operating conditions. The performance characteristics may be used to produce a generator capability model. The generator capability model may comprise a mathematical representation approximating the generator performance characteristics at the plurality of operating conditions. The system may further produce an estimated generator capacity at a modeled condition that is distinct from the generator performance characteristics of the data set and is based upon the generator capability model and may implement a control action based on the estimated generator capacity at the modeled condition.

Abstract: A packaged terminal air conditioner unit is provided. The packaged terminal air conditioner unit can include a heater bank jumper configured to couple one or more heater banks to a controller associated with the packaged terminal air conditioner unit. The heater bank jumper can be selectively configurable to provide at least one shunt line to couple at least one contact point associated with the controller to at least one contact point associated with the one or more heater banks. In this manner, the heater bank jumper can be configured based at least in part on an amount of current provided to the packaged terminal air conditioner unit by an electric service.

Abstract: An apparatus comprises an input node, a power rail to power a circuit load, and multiple current paths coupled in parallel with each other between the input node and the power rail. Each current path respectively provides a sense output to indicate current in the path and a current switch having a control input to control the current in the path. A control circuit, coupled to each control input individually and to each sense output individually, controls the current in each path individually based on the indicated current therein after a non-zero input voltage is initially applied to the input node, such that all of the paths concurrently conduct current from the input node to the power rail and collectively cause a total inrush current and corresponding voltage at the power rail to gradually increase.

Abstract: An automatic transfer switch includes a first switching apparatus having a first state to electrically connect at least one load to a primary power source and a second state to electrically connect the at least one load to a secondary power source; a sensor structured to sense information related to the power draw of the at least one load; and a control unit structured to determine the power draw of a selected one of the loads based on the output of the sensor, to compare the power draw of the selected load to a power capacity of the secondary power source, to allow the selected load to turn on if the power capacity of the secondary power source is at least greater than the power draw of the selected load, and to otherwise prevent the selected load from turning on.