Abstract: A circuit state sensing device (100) includes a transformer (102) having a primary coil (104A) and a secondary coil (104B). In use, the secondary coil is connected to a target circuit (106) for which a state is to be sensed. The device further includes a measuring arrangement (112, 122) configured to take a measurement relating to impedance at the primary coil, and a processing arrangement (122) configured to process the impedance measurement to determine a state of the target circuit.

Abstract: A lighting system for controlling a plurality of light sources includes at least a first and a second light source, the second light source having a color temperature and relative luminous efficiency higher than those of the first light source. Further, the system includes: a driving unit configured to turn on and off each of the light sources; and a control unit configured to transmit a control signal to the driving unit in response to an input signal. In addition, the control unit transmits the control signal to the driving unit, to perform at least one of a fade-in control in which the first light source is turned on prior to the second light source when turning on the light sources and a fade-out control in which the second light source is turned off or is dimmed, prior to the first light source when turning off the light sources.

Abstract: An industrial process variable transmitter includes a process variable sensor configured to sense a process variable. Measurement circuitry is coupled to the process variable sensor and provides a measured output as a function of the process variable. Output circuitry includes a loop connection configured to couple to a process control loop. An optical sensor receives the measured output from the measurement circuitry. A switching device applies pulses to the process control loop in response to an output from the optical sensor. Power supply circuitry powers the optical sensor, a comparator, and/or the switching device with power received from the process control loop and loop connection.

Abstract: The power supply includes a first power connector, a power conversion circuit, a control unit and a detection circuit. The first power connector includes a plurality of power terminals and a first detecting terminal. The power conversion circuit is coupled to the power terminals of the first power connector for converting an input voltage into an output voltage. The control unit is coupled to the power conversion circuit for controlling an operation of the power conversion circuit. The detection circuit is coupled to the control unit and the first detecting terminal of the first power connector for detecting if the first detecting terminal is connected or disconnected with a predetermined voltage terminal and correspondingly generating a power transmission status signal to the control unit.

Abstract: A differential protection system including a plurality of inputs power cables for transfer of power from electric power generators, such as wind power generators, to an output cable. Each input and output power cable is provided with a respective circuit breaker. The protection system includes a plurality of protection equipment unit each being adapted to be arranged at a respective one of the input cables or at the output cable, each protection equipment unit including a measuring unit for measuring the current and voltage of the cable, and including a control unit being operatively connectable to the circuit breaker of the respective power cable for selectively tripping the circuit breaker when the protection system discovers a differential fault. The protection system includes a charging current compensator for compensating the differential protection for charging currents of the cables of the transfer system.

Abstract: A distributed power system including multiple DC power sources and multiple power modules. The power modules include inputs coupled respectively to the DC power sources and outputs coupled in series to form a serial string. An inverter is coupled to the serial string. The inverter converts power input from the serial string to output power. A signaling mechanism between the inverter and the power module is adapted for controlling operation of the power modules.

Abstract: A power supply with arc flash protection mechanism for providing power to a load is disclosed. The power supply comprises a first power connector including a plurality of power terminals and a first detecting terminal, a power conversion circuit, a control unit and a connection status detection circuit. The power terminals of the first power connector are configured to couple with a plurality of power terminals of a second power connector, and the first detecting terminal is configured to couple with a second detecting terminal of the second power connector and provide a detecting signal indicative of whether the second power connector is being disconnected with the first power connector. When the first detecting terminal is disconnected with the second detecting terminal, a power connection status signal of the connection status detection circuit is under disable status and the control unit controls the power conversion circuit not to generate or output the output voltage to the load.

Abstract: A method for detecting faults in a solar cell includes measuring at least one operational parameter of a solar cell, measuring an output of the solar cell, identifying differences between the measured output of the solar cell and estimated outputs of a first and second model of operating modes of the solar cell, generating probabilities corresponding to the likelihood that each model corresponds to the actual operating mode of the solar call based on the identified differences, and disconnecting the output of the solar cell from a load in response to the identified current operating mode being the operating mode of the second model.

Abstract: A smart load switch or smart plug incorporates a built-in circuit that can monitor a physical variable condition and compare that sensed condition to data stored in a memory. A controller receives input data from the measuring device, compares the data to the reference data in memory, and selectively controls the on/off condition of a switch and thus the device that is plugged into the switch.

Abstract: A power transmission system a power transmission apparatus, a center frequency acquiring unit, and a control unit. The power transmission apparatus includes a primary-side coupling electrode electrically configured to couple to a secondary-side coupling electrode and connected load circuit of a power receiving apparatus, a high-frequency voltage generating circuit configured to generate and apply a high-frequency voltage to the primary-side coupling electrode, and a driving power circuit that supplies driving power to the high-frequency voltage generating circuit. The center frequency acquiring unit acquires a center frequency at which a high-frequency high voltage applied to coupling electrode is minimized in a state in which a low load is applied to the secondary-side coupling electrode of the power receiving apparatus and the frequency of the generated high-frequency voltage is varied.

Abstract: A circuit is used for preventing a computer from being powered up before a CPU voltage of the computer is prepared properly. The circuit includes a power supply for providing power to the computer, a power button for powering on the computer system, a power controller, and a switch. The power controller includes an input terminal connected to the power button and an output terminal for electrical connection to the power supply. The input terminal receives a PWRBT# signal when the power button is momentarily triggered, and the output terminal outputs a PSON# signal to the power supply to control the power supply to provide the electrical power to the computer in response to the received PWRBT# signal. The switch is serially connected between the output terminal and the power supply. The switch includes a control terminal monitoring if the CPU voltage is prepared properly so as to control conduction of the switch and further to control connection between the output terminal and the power supply.

Abstract: A transitioning of power dissipation in a processing device (11) is coordinated with the operation of a cooling system (16, 17, 18) for the processing device. A power transitioning arrangement (15) transitions power dissipation in the processing device (11) between a high power level and a relatively lower low power level. In conjunction with a transitioning of the processing device power level, the cooling system (16, 17, 18) is placed in either a high or low thermal impedance state to reduce the rate at which the temperature of the data processing device (11) and related elements change in response to the change in power dissipated by the processing device. Transitioning the power dissipation in the processing device (11) may be accomplished by gradually varying the clock rate for the device, by changing the clock rate to various processing elements in the device at different times, and/or by changing the instruction issue rate in the device.

Abstract: Power to a processor-based system is automatically disabled following a thermal condition detected by the processor. A predetermined thermal condition identified by the processor is coupled to a circuit that causes the power supply to be turned off. The response is substantially simultaneous to the predetermined thermal condition such that the processor and other integrated circuits located on the motherboard of the system may survive the thermal condition.

Abstract: A non-contact electric power transmission apparatus including a power supply unit and a load unit. The power supply unit has a first oscillation circuit, a signal secondary winding, a filter circuit, and a driving control circuit. The load unit has a power secondary winding, a signal primary winding, and a second oscillation circuit. The first oscillation circuit has a power primary winding and intermittently oscillates at a first oscillation frequency. When the load unit is placed at a predetermined position with respect to the power supply unit, since signals are induced in the power secondary winding by the signals in the power primary winding, the second oscillation circuit oscillates at a second oscillation frequency which is different from the first oscillation frequency. The signals from the second oscillation circuit are transmitted from the signal primary winding to the signal secondary winding.

Abstract: A power supply circuit is provided with a first battery, a second battery, an output terminal, and a voltage dividing circuit for dividing a voltage from the first battery. An output voltage of the dividing circuit is compared with a voltage of the second power source by a comparing circuit. A first P-channel-type MOSFET is connected between the first battery and the output terminal. A second P-channel-type MOSFET is connected between the second battery and the output terminal. Depending on an output from the comparing circuit, one of the MOSFET is turned on, and the other is turned off.

Abstract: A fast and reliable method for determining power system transient stability is presented for on-line power system dynamic security assessment. This method is based on the direct (Lyapunov theory) approach controlling the unstable equilibrium point (UEP). Lyapunov technique, however, cannot be used on-line, since calculating the controlling UEP is a computational intensive problem, even for a computer. The invention comprises determining the controlling UEP of a reduced system and relates the controlling UEP of the reduced system to the controlling UEP of the original system. The invention has a sound theoretical basis. The invention eliminates the difficulty of having to find the controlling UEP. The method of the invention determines the constant energy region that surrounds the controlling UEP of the original system. This region is used to approximate the stability region boundary intersection point that a particular fault trajectory will traverse.

Abstract: A power source device to and from which an interchangeable first device can be attached and detached and operating in such a manner that when the first device is attached and when the first device is judged to be normally operating, electric power is supplied at all times to the first device, while when the first device is not attached, or when, though the first device is attached, the first device is judged not to be normally operating, electric power is supplied in a predetermined periodicity to the first device.

Abstract: The method allocates a demanded amount of power to a plurality of power output apparatus, each power apparatus having characteristic curves associated therewith, and the total power outputted from the plurality of power apparatus results in a minimum cost for generating the power. Each boiler is allocated a quantity of waste fuel to be used in the generation of power, the quantity of waste fuel to be a predetermined total over a predetermined time period. Data is entered for each of the power apparatus into a controller. Optimal solutions are generated for all valid possible output power demands using an optimization by parts technique within bounds of each power apparatus. The solutions indicate the portion of power each power apparatus is to supply to provide the total power demanded at minimal cost. The solutions are stored in tables within a storage unit of the controller.

Abstract: The method allocates a demanded amount of power to a plurality of power output apparatus, each power output apparatus having an emissions curve associated therewith, such that each of the power output apparatus supplies a portion of the demanded power, and the total power outputted from the plurality of power output apparatus results in a minimum amount of emissions. Data is entered for each of the power output apparatus into a controller. Optimal solutions are generated for all valid possible output power demands using an optimization by parts technique within output power bounds of each of the power output apparatus. The solutions indicate the portion of power each power output apparatus is to supply to provide the total power demanded at minimal emissions output. The solutions are stored in tables within a storage unit of the controller. Upon receipt of a demand for power, a search is performed of the solution tables to obtain the amount of power each power output apparatus is to supply to meet the demand.

Abstract: The method allocates a demanded amount of power to a plurality of power output apparatus, each power output apparatus having characteristic curves associated therewith, such that each of the power output apparatus supplies a portion of the demanded power, and the total power outputted from the plurality of power output apparatus results in a minimum cost for generating the power as a function of a plurality of constraints. Data is entered for each of the power output apparatus into a controller. Optimal solutions are generated for all valid possible output power demands using an optimization by parts technique within output power bounds of each of the power output apparatus. The solutions indicate the portion of power each power output apparatus is to supply to provide the total power demanded at minimal cost and emissions output at or less than predetermined levels. The solutions are stored in tables within a storage unit of the controller.

Abstract: An induction heating apparatus for cooking includes an induction heating coil which generates a high frequency time-varying magnetic field used to heat a metal object; a high frequency inverting circuit which supplies a high frequency AC signal to the heating coil in response to the supply of power from a power source to control the heating coil to generate the magnetic field; a switch for connecting and interrupting the supply of power to the inverting circuit; a magnetic material detecting circuit which detects whether the object is made of a ferromagnetic material and which produces a magnetic detecting signal in response thereto; a control circuit which controls the inverting circuit in response to the magnetic detecting signal in the sense to supply the AC signal to the heating coil when the object is made of a ferromagnetic material; a switch circuit for supplying an override signal to the control circuit to cause the latter to control the inverting circuit in the sense to supply the AC signal to the he

Abstract: The control device has a power regulator for the timed power to the heating system of the electrical apparatus. The heating system is provided with a temperature sensor which, up to a given desired temperature, bridges the power regulator with the aid of a temperature switch, so that full power is supplied to the electrical apparatus heating system. On exceeding the desired temperature, power is supplied to the electrical apparatus via the power regulator.The temperature sensor is additionally heatable by an auxiliary heating system to obtain a variable changeover temperature of the temperature switch (22).The auxiliary heating system is preferably always switched on when the heating system of the power regulator is switched off.

Abstract: A frequency adaptive, power-energy re-scheduler (FAPER) that includes a frequency transducer that notes frequency or frequency deviations of an electrical system and logic means which controls and re-schedules power flow to a load unit in part on the basis of the deviations in frequency from a nominal frequency and in part on the needs to the load unit as expressed by an external sensor signal obtained from the physical system affected by the load unit.

Abstract: A timing control circuit for use in automatically and intermittently operating electrical appliances, such as lamps, for security purposes in homes, offices and other buildings. The circuit is adapted to plug into a conventional wall socket and to receive conventional two-prong plugs of electrical appliances. When enabled, the circuit intermittently applies power from the wall socket to a connected electrical appliance so that the appliance is turned on and off automatically over some period of time. The circuit includes manually operable switches to enable a user to select the intermittency or on-off pattern of operation of the appliance and the period of time over which such pattern is developed. Controlling turn-on and turn-off of lamps, radios, or the like gives the appearance of occupancy of a dwelling and therefore discourages would be burglars and prowlers.

Abstract: A condition responsive time proportional control means which has a relatively fast time constant when operating in its proportional band has the time constant expanded by means of a digital counter. The counter is repetitively switched by the condition responsive means and counts the switched operation. During the period that the switched operation is occurring, the time constant is expanded by simultaneously counting pulses from a pulse generating means.

Abstract: A condition responsive time proportional control means which has a relatively fast time constant when operating in its proportional band has the time constant expanded by means of a digital counter. The counter is a resettable unidirectional type counter. The output of the counter drives a switch means and a load along with a means for altering the time constant of the condition responsive time proportional control means. The time constant is altered by a switching means that changes the charge and discharge path of a capacitor used in creating the time constant.

Abstract: There is disclosed a method and means for continuously controlling the consumption of power by an industrial customer wherein the control is accomplished by controlling the generation of the customer's own power source and/or his load in response to a signal representing the change necessary to make the energy consumed equal the demand limit. The gain of the control response is modified so that it is increased with increases in the difference between the energy actually consumed and the desired consumption.

Abstract: The control system permits limiting the electrical demand of a distribution network to a desired maximum value by regulating the temperature of one or more thermal loads with heating or cooling elements; this system includes: means for measuring the instantaneous demand of the network; means for measuring the instantaneous temperature of each of the thermal loads; means for comparing the demand of the network to the desired maximum value; means for comparing the measured temperature to the desired temperature for each of the thermal loads; and means for disconnecting or for connecting in response to the information obtained by the comparison, a fraction of the elements which is proportional to the difference between the measured temperature and the desired temperature.

Abstract: The self-calibrating leak detector circuit arrangement comprises a measuring probe for generating an electrical signal when exposed to the leaking gas. A measuring amplifier is connected to the probe for amplifying the electrical signal and a second integrating amplifier stage is connected to the measuring amplifier output for amplifying the signal. The second amplifier stage has a feedback connection to the input of the measuring amplifier for counteracting at least a part of the electrical signal from the probe. A push button switch is advantageously connected between the measuring amplifier and the second amplifier stage to momentarily impress the output of the measuring amplifier on the input of the second integrating amplifier stage. Indicators are connected to the outputs of the respective amplifiers for a reading of their respective outputs.