Systems, methods, and other embodiments associated with identifying non-technical line loss using data from smart meters in an electric grid are described. In one embodiment, a method includes querying a utility database to collect meter data, wherein the meter data is from electric meters connected to a transformer in an electric grid. Querying the utility database includes collecting the data according to a plurality of intervals over a period of time. Electric consumption and voltage variances are analyzed for the set of meters to identify a first set of intervals that satisfy a threshold for electric consumption and to identify a second set of intervals that satisfy a threshold for voltage variances. The first set of intervals is compared with the second set of intervals to determine whether the set of meters are associated with non-technical line loss.

A light-emitting diode (LED) luminaire comprises an emergency-operated portion comprising a battery, a self-diagnostic circuit comprising a test portion configured to auto-evaluate battery performance, a first controller, and a node modulator-demodulator (MODEM). The LED luminaire can auto-switch from a normal power to an emergency power according to availability of the normal power and whether a battery test is initiated. The first controller is configured to communicate between the test portion and the node MODEM, ensuring command data and test data respectively to be transferred to the self-diagnostic circuit and to a remote control unit that comprises a data-centric circuitry comprising a variety of data communication devices configured to initiate the command data with phase-shift keying (PSK) signals transmitted via a principal MODEM and to periodically collect the test data to and from the node MODEM. The test data assembled are ultimately transferred to a root server for further reviews.

A lighting device includes: a DC power source circuit; an output control circuit including a chopping switch to adjust an output current by chopping of the chopping switch; light source switches respectively connected to the light sources; and a control unit for controlling a time period for which a current flows in the light sources. The control unit controls the output control circuit such that an operation period for which the chopping is conducted and a stop period for which the chopping is stopped are repeated alternately and performs switchover of the light source switches to be sequentially and selectively turned on, and the switchover is conducted during the stop period with a time interval from a beginning of the stop period.

A method is provided for controlling a converter of the multiphase interleaving type. According to the method, there is detected when a change of the load applied to an output terminal of the converter occurs. All the phases of the converter are simultaneously turned off, and a driving interleaving phase shift is recovered so as to restart a normal operation of the converter. A controller for carrying out such a method is also provided.

An energy recovery snubber circuit for a power converter which includes a flyback transformer driven by a converter switch is disclosed. The snubber circuit includes two capacitors which are connected such that, when the snubber circuit is connected to a primary winding of the flyback transformer, the capacitors are charged in series by current flowing in a first direction in the primary winding when the converted switch is turned OFF, to recover energy stored in the leakage inductance of the transformer, and discharged in parallel to cause current flow in a second direction in the primary winding of the transformer, to thereby transfer the recovered energy to the transformer.

A DC-DC converter having a coupling network is provided, in which the coupling network is so configured as to forcibly add a noise source to a feedback output voltage of the DC-DC converter. The coupling network includes one coupling resistor and two coupling capacitors to include the switching voltage of a power switch and inductor output voltage into the output voltage, and transmit the result together with the feedback output voltage to the comparator. Accordingly, it is easier to compare the reference voltage and the feedback voltage, and stably maintain the output voltage of the DC-DC converter operating in constant on-time (COT).

An electrical circuit for providing electrical power for use in powering electronic devices is described herein. The electrical circuit includes a primary power circuit and a secondary power circuit. The primary power circuit receives an alternating current (AC) input power signal from an electrical power source and generates an intermediate direct current (DC) power signal. The intermediate DC power signal is generated at a first voltage level that is less than a voltage level of the AC input power signal. The secondary power circuit receives the intermediate DC power signal from the primary power circuit and delivers an output DC power signal to an electronic device. The output DC power signal is delivered at an output voltage level that is less than the first voltage level of the intermediate DC power signal.

Disclosed is a light emitting device having a configuration that, when a magnitude of an input voltage is greater than a minimum light emitting voltage, all light emitting devices are turned on regardless of the magnitude of the voltage. As the magnitude of the voltage is smaller, the light emitting devices are connected in parallel. As the magnitude of the voltage is greater, the light emitting devices are serially connected.

In an embodiment, method of controlling an illumination device by an output signal of a DC-DC converter is disclosed. The output signal is controlled by a PWM signal. The method includes receiving a feedback signal corresponding to variation in the output signal with respect to a pre-determined output signal, and determining a target duty cycle of the PWM signal based on the feedback signal. The PWM signal of the target duty cycle is capable of enabling the DC-DC converter to generate the pre-determined output signal. The method includes providing the PWM signal of an effective duty cycle equal to the target duty cycle over N switching pulses of the PWM signal to the DC-DC converter. The method provides the PWM signal by providing M switching pulses of a first PWM signal of a first duty cycle, and N−M switching pulses of a second PWM signal of a second duty cycle.

A power supplying apparatus includes a voltage outputting module and a voltage selecting module. The voltage selecting module is electrically connected to the voltage outputting module. The voltage selecting module includes a returning unit. The voltage selecting module receives a voltage identification signal when the voltage outputting module is electrically connected to an electronic device. When the voltage identification signal is larger than a voltage level, the returning unit notifies the electronic device, such that the electronic device returns a voltage request signal. The power supplying apparatus selectively sends out one of a plurality of DC voltage signals to the electronic device according to the voltage request signal.