Abstract: The control apparatus includes an electrical signal detection unit, a control unit, a contactor, a first execution unit, a protection unit, and a second execution unit. The electrical signal detection unit detects an electrical signal on a loop, and send the electrical signal to the control unit. The control unit generates a control signal, and send the control signal to the first execution unit. The contactor is connected to the loop. The first execution unit controls the contactor to be closed or opened, where when the contactor is closed, the loop is connected, and when the contactor is opened, the loop is disconnected. The protection unit detects a current value on the loop when the contactor is closed, where an opening instruction is sent to the second execution unit when the current value reaches a trip threshold. The second execution unit opens the contactor when receiving the opening instruction.

Abstract: Provided is a scheme of providing a plurality of users other than a main user such as an owner with a discharge capacity which a secondary battery system potentially has. A user interface providing device includes an acquisition part, a receiving part, a determination part, and a generation part. The acquisition part acquires a discharge capacity capable of providing to a whole plurality of users other than a main user in a discharge capacity of a secondary battery system. The receiving part receives a logon of a user included in the plurality of users. The determination part determines a usable discharge capacity for a logged-on user from the discharge capacity capable of providing to the whole plurality of users. The generation part generates information indicating contents of a user interface screen including a screen element indicating the usable discharge capacity for the logged-on user.

Abstract: A method for optimizing power distribution amongst one or more electrical supply equipment stations at a power distribution site is provided. The method includes obtaining infrastructure data about the power distribution site, obtaining vehicle/transport climate control system data from one or more transport climate control systems and one or more vehicles demanding power from the one or more electrical supply equipment, and obtaining external data from an external source that can impact power demand from the one or more transport climate control systems. Each of the one or more transport climate control systems configured to provide climate control within a climate controlled space. The method also includes generating an optimized power distribution schedule based on the infrastructure data, the vehicle/transport climate control system data and the external data, and distributing power to the one or more transport climate control systems based on the optimized power distribution schedule.

Abstract: An apparatus for detecting Packet Energy Transfer (PET) in a cable is disclosed herein. The PET detecting apparatus includes an input adapted to generate a current by operative communication of the input with the cable, wherein the cable communicates PET as a pulse train. A spectral analyzer compares frequencies of maxima of the power spectrum of a signal derived from the current with a fundamental frequency of the pulse train and a harmonic frequency of the pulse train to detect PET in the cable. A power maximum of the power spectrum at the fundamental frequency and a second power maximum of the power spectrum at the harmonic frequency indicates PET in the cable. No power maximum of the power spectrum at the fundamental frequency or no second power maximum of the power spectrum at the harmonic frequency indicates no PET in the cable.

Abstract: A method of dedicated circuit verification using a monitoring system includes measuring current at circuit breaker, comparing breaker current with microinverter current generated from one or more solar panels and determining whether they are within a threshold amount of one another, and generating an output based on the comparison.

Abstract: Dynamic allocation of power modules for charging electric vehicles is described herein. A power cabinet includes multiple power modules that each are capable of supplying an amount of power to a dispenser. Multiple dispensers are coupled with the same power cabinet. A first power bus couples a first dispenser and switchably connects the power modules to the first dispenser; and a second power bus couples a second dispenser and switchably connects the power modules to the second dispenser. The power cabinet includes a control unit that is configured to cause the power modules to switchably connect and disconnect from the first power bus and the second power bus to dynamically allocate the power modules between the first dispenser and the second dispenser.

Abstract: A system for charging multiple electric vehicles is provided. The system includes a first electrical converter that supplies DC power to a ring bus. The ring bus is separated into a plurality of DC buses by electrical breakers. Second converters are connected to the ring bus and convert the DC power supply to a DC voltage suitable for charging electric vehicles connected thereto.

Abstract: In one or more embodiments, one or more systems, methods, and/or processes may query each component of multiple components of a system for multiple power utilization attributes associated with the component; may determine a power budget based at least on each multiple power utilization attributes of each component of the multiple components; may determine an integer number of power supply units based at least on the power budget; may determine a fail safe power level based at least on power provided by the integer number of power supply units; may determine, based at least on the fail safe power level, multiple component fail safe power levels respectively associated with the multiple components of the system; and may provide, to each component of the multiple components, configuration information associated with a respective component fail safe power level, of the multiple component fail safe power levels, respectively associated with the component.

Abstract: A charging circuit includes a first energy harvesting element that performs energy harvesting and supplies a current to a power storage element, a second energy harvesting element that performs energy harvesting, the second energy harvesting element is made in materials same as the first energy harvesting element, and a first switch that is disposed in a current path between the first energy harvesting element and the power storage element and that is put into an off-state, in a case where a first output voltage of the second energy harvesting element is smaller than a first value, thereby cutting off the current path.

Abstract: An apparatus comprises a power electronic energy conversion system comprising a first energy storage device configured to store DC energy and a first voltage converter configured to convert a second voltage from a remote power supply into a first charging voltage configured to charge the first energy storage device. The apparatus also includes a first controller configured to control the first voltage converter to convert the second voltage into the first charging voltage and to provide the first charging voltage to the first energy storage device during a charging mode of operation and communicate with a second controller located remotely from the power electronic energy conversion system to cause a second charging voltage to be provided to the first energy storage device during the charging mode of operation to rapidly charge the first energy storage device.

Abstract: The present disclosure provides an adaptive energy storage operating system that is programmed or otherwise configured to operate and optimize various types of energy storage devices.

Abstract: Dynamic allocation of power modules for charging electric vehicles is described herein. A power cabinet includes multiple power modules that each are capable of supplying an amount of power to a dispenser. Multiple dispensers are coupled with the same power cabinet. A first power bus couples a first dispenser and switchably connects the power modules to the first dispenser; and a second power bus couples a second dispenser and switchably connects the power modules to the second dispenser. The power cabinet includes a control unit that is configured to cause the power modules to switchably connect and disconnect from the first power bus and the second power bus to dynamically allocate the power modules between the first dispenser and the second dispenser.

Abstract: The present application relates to a charger for electric vehicles, comprising at least two power exchange ports for vehicles, each port comprising a data communication connection for at least receiving a power request from a vehicle, and a power exchange connection for delivering power to a vehicle; at least one grid connection for receiving electric power; a data communication bus, for communicating the power request from the vehicles to a plurality of autonomously controllable power converters, each for converting power from the grid connection to a suitable level for charging a vehicle; and each of the power converters comprises a data communication device, connected to the data bus, and configured for receiving power requests from vehicles; and configured for indicating its available power via the data bus.

Abstract: The present invention provides an energy storage system that utilizes batteries of multiple compositions and provides improved load sharing between the different types of batteries is disclosed. The energy storage system includes at least two batteries, where each battery has a different chemical composition for storing energy. One battery is configured for rapid charging/discharging and the other batter is configured for slower charging/discharging. Each battery is connected to a common connection via an energy regulator. The regulators are initially configured such that the energy regulator connected between the common connection and the battery configured for rapid charging/discharging responds initially to changes in power demand at the common connection. If power demand continues, the first regulator decreases the amount of energy transferred between the first battery and the common connection while the second regulator begins transferring energy between the second battery and the common connection.

Abstract: A load control receiver (LCS) for controlling an electrical load. The LCS includes a power sensing arrangement that monitors power usage of the load; a processor that predicts future power usage based on prior power usage; a transceiver that receives load shedding commands; and a controllable switch that can interrupt power supplied to the attached loads, based on load shedding commands.

Abstract: Apparatuses, methods and systems for managing a building load reduction of a plurality of loads within a building are disclosed. One method includes assigning one or more loads of the plurality of loads to logical groups, assigning a sensitivity coefficient to each of the logical groups, wherein the sensitivity coefficient is directly proportional to an impact on occupants in the building to load changes, determining the baseline load for each of the logical groups, receiving a power reduction demand response, and reducing a load of each logical group based upon the sensitivity coefficient.

Abstract: The present invention provides a simplified method of controlling power among the various sources and loads in a power system. Power generating sources are each connected to a common DC bus through a converter. The converter selectively transfers energy to the DC bus at a maximum rate or at a reduced rate according to the level of the DC voltage present on the DC bus. At least one storage device is preferably connected to the common DC bus through a power regulator. The power regulator selectively transfers energy to or from the DC bus as a function of DC voltage level present on the DC bus. Further, an inverter may be provided to bidirectionally convert between the DC voltage and an AC voltage for connection to a customer load or the utility grid. Each power conversion device is independently controlled to provide a modular and simplified power control system.

Abstract: The disclosure relates to a field device of a process automation system, having at least one first intrinsically safe power supply unit, which provides locally stored electrical energy in an integrated storage element for supplying power to an electronics unit for process control. To supply power to intrinsically safe field devices from locally stored electrical energy in line with demand, it is proposed that in addition, at least one additional intrinsically safe power supply unit is integrated therein, which is fed by a power generation unit providing locally renewable electrical energy.

Abstract: A monitoring system capable of being operationalized. Power consumption in electrical devices is monitored by the use of new and innovative consumption power monitoring device in accordance with the present invention. Power consumption information is collected by an intelligent power hub that is communicatively coupled to a remote server that presents overall power usage displays. A method of operationalizing a power usage monitoring system comprises powering up an energy pump device when the energy pump device is plugged into a first power socket, setting the energy pump device automatically to a SET mode to acquire new monitoring devices, and discovering the presence of a power consumption monitoring device.

Abstract: A method includes detecting removal or depletion of a power supply associated with a powered device. The powered device is configured to receive power from a power adapter via a narrow-voltage direct current/direct current (NVDC) charger and from the power supply. The method also includes, in response to the detection, disabling a dynamic power management function of the NVDC charger. The method further includes monitoring input current or input power provided to the powered device by the NVDC charger and determining if the input current or input power exceeds a threshold. In addition, the method includes, if the input current or input power exceeds the threshold, triggering a throttling of an operating clock frequency of the powered device. The method could also include (i) disabling a specified mode of operation and turning on a voltage regulator of the NVDC charger in response to the detection and (ii) providing over-voltage protection.

Abstract: The present invention discloses a power bank circuit. The power bank circuit includes a charger circuit, a battery circuit, a power conversion circuit, a temperature detecting circuit and a current distribution circuit. The charger circuit receives an input voltage and provides a charging current to the battery circuit. The power conversion circuit converts a battery voltage to an output voltage and provides an output current. The temperature detecting circuit detects the temperature of the packaged structure. When the temperature of the packaged structure exceeds a first predetermined temperature, the current distribution circuit first reduces the output current. When the temperature of the packaged structure exceeds a second predetermined temperature, the current distribution circuit then reduces the charging current.

Abstract: An activation control apparatus includes a voltage fluctuation obtainer to obtain voltage fluctuation amplitude of an external power source at a given voltage, the voltage fluctuation caused when activating an apparatus using the external power source; a voltage fluctuation detector to detect the voltage fluctuation of the external power source at the given voltage; an activation controller to determine whether the voltage fluctuation amplitude obtained by the voltage fluctuation obtainer at the given voltage of the external power source, detected by the voltage fluctuation detector, is within a preset allowable voltage fluctuation range, and to control activation of the apparatus using the external power source based on a result of the voltage fluctuation determination made by the activation controller.

Abstract: This invention is directed towards a waste enclosure device (“device”) comprising a waste enclosure employing operational functions including collection and monitoring capacity wherein said device includes one or more programmable logic controllers. Operational functions are performed by electrical components including sensors to determine waste deposits characteristics and contents. Said device operational functions are further adapted to send and receive data, optionally wirelessly, and configured and adapted to utilize solar derived electric power and, optionally, electric power from other sources.

Abstract: A lamp base having an electrical device recharging receptacle configured to receive a plug from a recharging device for a portable rechargeable electronic device. The receptacle is configured as a standard automobile cigarette lighter receptacle. The receptacle includes standard cigarette lighter receptacle electrical contacts that are connected to a voltage and current conversion circuit for receiving standard household voltage and converting it into standard automotive voltage and current. An adapter receptacle is provided in the lamp base with securable replacement electrical and mechanical connection mechanism, wherein the conversion circuit provides a voltage and current to the adapter receptacle. A replaceably securable USB adapter plug comprising a second conversion circuit for converting the voltage and current provided to the adapter receptacle into a standard USB voltage and current.

Abstract: A control unit of a system stabilization device uses a fluctuation detection block (60) to determine fluctuation components included in the active component and reactive component currents of a system current and fluctuation components included in the frequency signal and the amplitude signal of a system voltage. The high frequency cut-off of the fluctuation detection block (60) is set to be f1; the low frequency cut-off is set to be f2. The fluctuation detection block (60) is composed of a low-pass filter (61) with a time constant of T1, a low-pass filter (62) with a time constant of T2, a subtracter (63) which outputs the difference, between the output signals of the filter (61) and the filter (62), and a feedback circuit (64) which provides feedback on the output of the subtracter (63) to the filters (61, 62). Thus, stability is ensured without using a current detector.

Abstract: A technique for combining power to a single load from multiple power supplies using power over Ethernet (PoE) is disclosed. Each power supply is coupled to associated power sourcing equipment (PSE) providing PoE, and each PSE has a current limit. The power supplies supply approximately the same voltage, but the output voltages are typically not exactly equal. All the power supplies are connected via diodes to a common load terminal. The power supply outputting the highest voltage first supplies power to the load terminal, since only its diode is forward biased, until a PoE current limit is reached. Then its duty cycle is limited. The load terminal voltage is then inherently lowered to cause the diode of the power supply with the next highest output voltage to connect it to the load to supply additional power to the load as the first power supply continues to supply its limited current.

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

Abstract: An electric power control apparatus, an electric power control method, and an electric power feeding system by which the maximum operating point of a generating element such as a solar battery can be controlled to be maintained, and electric power loss can be avoided. The electric power control apparatus is provided with an electric power path switch unit to which a plurality of generating elements can be connected, and a voltage conversion unit that converts a voltage level which is generated by the generating elements and supplied via the electric power path switch unit. The electric power path switch unit includes a first connection switching function which switches between series connection and parallel connection for the plurality of generating elements, and a second connection switching function which switches between connected and non-connected to an input side of the voltage conversion unit for the generating elements connected in series or parallel.

Abstract: The disclosure relates to a field device of a process automation system, having at least one first intrinsically safe power supply unit, which provides locally stored electrical energy in an integrated storage element for supplying power to an electronics unit for process control. To supply power to intrinsically safe field devices from locally stored electrical energy in line with demand, it is proposed that in addition, at least one additional intrinsically safe power supply unit is integrated therein, which is fed by a power generation unit providing locally renewable electrical energy.

Abstract: The disclosed power distribution system regulates the transfer of energy from a source 1 to a load 3. Source Controller 5 on the source side closes Disconnect Device 7 and monitors the transfer of a pulse or “packet” of energy to the load side. A Load Controller 9 on the load side communicates the amount of energy received at the load back to the source controller via Communication Link 11. If it is confirmed that the energy received on the load side corresponds to that sent by the source side, another energy packet is sent. If the energy received does not correspond with that sent by the source side, energy transfer is stopped, indicating a system fault or safety hazard. The energy content of a single packet is kept small, such that if it is not properly delivered, it can not cause damage to equipment or harm personnel.

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

Abstract: A lamp base having an electrical device recharging receptacle configured to receive a plug from a recharging device for a portable rechargeable electronic device. The receptacle is configured as a standard automobile cigarette lighter receptacle. The receptacle includes standard cigarette lighter receptacle electrical contacts that are connected to a voltage and current conversion circuit for receiving standard household voltage and converting it into standard automotive voltage and current.

Abstract: A method for wear leveling in an information handling system including multiple power supply units (PSUs) is provided. The method includes maintaining each PSU in one of multiple different operational states, collecting data relating to the use of each PSU, storing the collected data, and automatically changing the operational state of at least one of the PSUs based at least on the collected data regarding the use of each PSU in order to level the wear on the PSUs.

Abstract: Apparatus and method for transmitting over non-adjacent multiple conducting pairs and aggregating powers from the conducting pairs to power remote electronic devices at an end station include, at a line termination (LT), a plurality of power transmitting circuits configured to transmit power over the multiple conducting pairs, and a microcontroller coupled to the plurality of power transmitting circuits and configured to receive a current sense signal from a power receiving circuit at the remote electronic device, and further include, at a network termination (NT), one or more current limiters coupled to multiple conducting pairs and operable to limit the power from the conducting pairs based on power demand information of the end station, and a load controller coupled to the one or more current limiters and configured to selectively activate the one or more current limiters based on a determination by the microcontroller that the end station is allowed to receive a full power demand, the determination being

Abstract: Control of a variable output appliance of a small energy consumer participating in an electrical load shedding program. A baseline operating characteristic of the appliance is determined for ordinary operation (such as in an absence of any load shedding requirements). An amount by which to reduce output of the appliance is determined in accordance with the load shedding program. Operation of the appliance is controlled to achieve the output reduction in accordance with the load shedding. This approach enables providing incentive for the small energy consumer to participate in the load shedding program, the incentive being based on the amount by which output is reduced, thereby representing a reduction of actual energy consumption for that small energy consumer.

Abstract: An improved method and system for facilitating no-break power transfer between an APU and a main engine includes determining a required APU speed for conducting power transfer based on various APU operating parameters, such as engine speed, fuel, environmental temperature, etc. The APU controller then adjusts the APU speed up or down to the required APU speed. Communication between an aircraft computer and the APU controller may also be provided so that operational data can be exchanged to adjust the electrical load of the aircraft below a maximum load threshold set by the APU, avoiding overloading of the APU during power transfer. By exchanging operational data between the APU controller and the aircraft computer, both the APU and the electrical load can be adjusted to optimize no-break power transfer despite varying APU operating conditions and main engine generator frequencies.

Abstract: A method of monitoring and regulating the power and the energy consumed by a transport system including electrically propelled vehicles, said transport system including a power supply system including one or more power supply substations connected to an external electrical power supply network, said power supply substation or substations supplying energy to traction substations supplying power to power supply line sections having vehicle-mounted current pick-up means connected thereto, each vehicle carrying a power converter which is supplied with power by said current pick-up means and which monitors the power supplied to a traction motor of said vehicle, which method includes the following steps: measuring the instantaneous electrical power and/or energy drawn from the external electrical power supply network by said power supply substation or substations, and if the power or energy drawn from the external network tends to exceed an assigned threshold, sending one or more vehicles a set point acting on t

Abstract: A wind park with a plurality of wind energy plants, which each have one plant control, which presets a desired value for the active power to its wind energy plant, and with a park control, which presets a desired value for the active power to be generated for each plant control and limits the active power fed by the wind park to a preset value, by shutting down a first group of wind energy plants and presetting a desired value for the active power to a second group of wind energy plants at a time, characterised in that the park control starts the wind energy plants of the first group again when the sum of the actual values of the active power of the wind energy plants of the second group has reached the preset desired value and/or a predetermined time duration has elapsed.

Abstract: An information handling system power supply system has a plurality of power supply units (PSUs) with outputs connected in parallel and a current balancing circuit for equalizing current from these outputs. A pseudo output current value may be added to the actual output current value for each PSU so that the parallel load sharing current balance system thinks all of the PSUs are sharing the load equally. This allows simple and inexpensive paralleling of differently rated PSUs without complex load sharing circuitry. Also, PSU stress factors may be easily compensated. For each PSU there may be a first voltage, VS1, generated that is proportional to the output current of the respective PSU. A pseudo current bias voltage, VIbais, is added to the first voltage, VS1, to produce a biased second voltage, VS2, (VS2=VS1+VIbais). The biased second voltage, VS2, now represents the apparent current output of the respective PSU when current load balancing each PSU of the power supply system.

Abstract: A charging system for simultaneously charging the batteries of a plurality of battery powered vehicles. The charging includes one or more DC-DC power converters having one or more charging ports configured to plug into the batteries. The DC-DC power converters are each configured to selectively connect to more than one charging port to selectively provide for higher port power levels. The DC-DC power converters connect to an AC rectifier through a DC bus. The AC rectifier connects to an AC power source having a limited power rating. The AC charging system also has a controller that controls the operation of the DC-DC power converters such that the total power draw on the AC rectifier does not exceed the power rating. The system is further configured such that the DC-DC power converters can drain selected batteries to obtain power for charging other batteries, thus allowing for batteries to be cycled.

Abstract: A system and method for converting power are disclosed.

Abstract: A system to manage energy may include a plurality of energy storage modules. Each energy storage module may include a power converter couplable to a link and a power converter controller to control operation of the power converter. Each energy storage module may also include at least one energy storage unit connected only to the power converter. The system may also include a power management controller to control power delivery from each of the plurality of energy storage modules to the link and to control power delivery to each of the plurality of energy storage modules.

Abstract: A portable computer includes a portable computer body having an upper surface, a lower surface and a lower front edge thereof. An add-on battery is detachable mounted on the lower surface of the portable computer body and has a wedge-shaped portion corresponding to a wedge-like space which is defined between the lower surface of the portable computer body and a surface on which the portable computer body is placed, when the portable computer body is placed to be inclined about the lower front edge of the portable computer body. The portable computer body is, when it is equipped with the add-on battery, inclined in such a manner that the upper surface of the portable computer body is lower at a front edge thereof.

Abstract: A power limiting system and method are provided for limiting power delivered to a common bus in a one or multi-frame tape library environment. The system includes one or more frames coupled to a common bus, each of which is capable of delivering power to the common bus. Each frame comprises current limiting circuitry to limit the power delivered by that frame to the common bus. In exemplary embodiments, the current limiting circuitry of each frame includes a current limiting resistor and a blocking diode coupled to a local power source to limit the power delivered by that frame and to prevent feedback respectively. Additionally, each frame of the system includes a relay capable of receiving a limited power from the common bus, being energized, and, consequently, providing for the respective frame to be powered by a main power supply.

Abstract: In an active mode, a controller switches an operation mode from the active mode to a suspend mode when an acceptance preparation completion signal is not received from downstream or when a circuit board is discharged downstream, if a discharge preparation completion signal has not been received from upstream. The controller controls relay apparatuses and adjusts a flow of current to control units, in addition to controlling its own CPU clock frequency.

Abstract: Circuits and methods for controlling load sharing by multiple power supplies are provided. In preferred embodiments, load share controllers utilize multiple voltage control loops to monitor the output voltages that are being provided by multiple power supplies connected to a load. These voltage control loops each generate a voltage control voltage that is proportional to the difference between the actual output voltage of the corresponding power supply and the desired output voltage. The voltage control loop with the highest voltage control voltage then controls a current control voltage generated in a current control loop for each power supply via a share bus. These current control loops then regulate the current provided by the corresponding power supplies so that those currents are all proportional to the voltage on the share bus.

Abstract: A power limiting system and method are provided for limiting power delivered to a common bus in a one or multi-frame tape library environment. The system includes one or more frames coupled to a common bus, each of which is capable of delivering power to the common bus. Each frame comprises current limiting. circuitry to limit the power delivered by that frame to the common bus. In exemplary embodiments, the current limiting circuitry of each frame includes a current limiting resistor and a blocking diode coupled to a local power source to limit the power delivered by that frame and to prevent feedback respectively. Additionally, each frame of the system includes a relay capable of receiving a limited power from the common bus, being energized, and, consequently, providing for the respective frame to be powered by a main power supply.

Abstract: Circuits and methods for controlling load sharing by multiple power supplies are provided. In preferred embodiments, load share controllers utilize multiple voltage control loops to monitor the output voltages that are being provided by multiple power supplies connected to a load. These voltage control loops each generate a voltage control voltage that is proportional to the difference between the actual output voltage of the corresponding power supply and the desired output voltage. The voltage control loop with the highest voltage control voltage then controls a current control voltage generated in a current control loop for each power supply via a share bus. These current control loops then regulate the current provided by the corresponding power supplies so that those currents are all proportional to the voltage on the share bus.

Abstract: An apparatus for providing power to an automated material handling system that includes a track on which a plurality of electrically powered material transport vehicles are mounted comprises a plurality of current-limited power sources each having a power supply lead and a power return lead. The apparatus further includes a power supply distribution network that is configured and arranged to electrically connect the power supply leads of the plurality of power sources together and to couple the current supplied therefrom to the power supply input of at least one of the plurality of material transport vehicles. And further includes a power return network configured and arranged to electrically couple the power return output of at least one of the plurality of material transport vehicles to the interconnected power return leads of the plurality of power sources.

Abstract: A proximity detector having a power switch 30 which is switched as a function of the approach of an object. The detector includes a MOS depletion transistor T1 which connects one of the terminals 15 of the detector to a control input of a power switch 30 through a control switch T2. A regulator stage 45 is coupled to T1 in order to keep T1 saturated in the closed condition of the detector and to regulate the gate voltage of T1 when the detector is in a open state.