A method of estimating a root mean square (RMS) of an alternating current (AC) voltage is provided. The system includes a rectifier configured to rectify the AC voltage and a controller configured to derive a delayed AC voltage by delaying the rectified AC voltage by a preset delay time. The controller is configured to estimate a root mean square (RMS) of the AC voltage based on the rectified AC voltage and the delayed AC voltage.

This application discloses an alternating-current energy detection apparatus, in which a voltage detection unit forms a coupling capacitance together with a tested cable, obtains a first voltage based on an actual voltage and the coupling capacitance, and outputs the first voltage to a data processing unit; a current detection unit detects a tested-cable current, and outputs the tested-cable current to the data processing unit; and the data processing unit receives the first voltage and the tested-cable current, and determines a first voltage value and a tested-cable current value; calculates a product of the first voltage value and a quantity of amplification times of a tested-cable voltage, and determines a tested-cable voltage value; and calculates, based on the tested-cable voltage value and the tested-cable current value, electric energy transmitted by the tested cable.

A method comprises: providing a welding current pulse through a welding circuit to create an arc for a welding operation; measuring an arc voltage to produce a measured arc voltage pulse that includes an inductive voltage drop due to inductance in the welding circuit and current ramps of the welding current pulse; and during the welding operation, implementing an inductance-compensation feedback loop. The feedback loop includes canceling the inductive voltage drop from the measured arc voltage pulse using a canceling voltage to produce a compensated arc voltage pulse; and deriving the canceling voltage based on the compensated arc voltage pulse.

A circuit includes a tank capacitor coupled between first and second nodes, and a sense resistor having a first terminal coupled to the first node and a second terminal coupled to a regulator input. A switching circuit has first and second inputs coupled to the first and second terminals of the sense resistor. A gain stage has first and second inputs capacitively coupled to first and second outputs of the switching circuit. An analog-to-digital converter receives the output of the gain stage, and receives first and second differential voltages. A reference voltage generator has a temperature independent current source coupled to source current to a reference resistor, the first differential reference voltage being formed across the reference resistor. The reference resistor and sense resistor are located sufficiently close to one another on a single common substrate such that they remain at substantially a same temperature.

The invention relates to a phase detection method (200) comprising the following steps: receiving (201) a receiving sequence (Y.sub.j) of values (Y.sub.0, Y.sub.1, . . . , Y.sub.N-1) of a receiving signal (Y), said values (Y.sub.0, Y.sub.1, . . . , Y.sub.N-1) having been sampled with a known sampling frequency f.sub.s and said receiving signal (Y) representing a reaction to a transmitting signal having a known transmitting frequency f.sub.w; providing (202) a sine sequence (S.sub.j) and a cosine sequence (C.sub.j) for each index (j) of the receiving sequence (Y.sub.j), said sine sequence (S.sub.j) comprising sine values of consecutive multiples of a known circular frequency, which depends on the transmitting frequency and the sampling frequency, and said cosine sequence (C.sub.j) comprising cosine values of consecutive multiples of the known circular frequency; and determining (203) a phase real part (U) of the receiving signal (Y) based on a scalar product of the receiving sequence (Y.sub.j) with the cosine sequence (C.sub.j) and a phase imaginary part (V) of the receiving signal based on a scalar product of the receiving sequence (Y.sub.j) with the sine sequence (S.sub.j).

To provide a measurement method of characteristics of an electrical element which causes variation in the luminance of pixels. In a device which includes components (pixels) arranged in a matrix and a wiring and where each component is capable of supplying current to the wiring through an electrical element included in each component, supply and non-supply of current of N components are individually set and current flowing through the wiring is measured N times. In the respective N measurements, combinations of the supply and non-supply of current in N components capable of supplying current to the wiring differ from one another. The amount of current flowing through each electrical element is obtained based on current obtained by the N measurements and the combinations of supply and non-supply of current in the N measurements.

A current measurement circuit includes first, second, and third conductors, a first current sensor, a second current sensor, and current computation circuitry. The first conductor is configured to conduct a first phase current of a three-phase current. The second conductor is configured to conduct a second phase current of the three-phase current. The third conductor is configured to conduct a third phase current of the three-phase current. The first current sensor is coupled to the first, the second, and the third conductors. The second current sensor is coupled to the second conductor and the third conductor. The current computation circuitry is coupled to the first current sensor and the second current sensor, and is configured to determine the first current, the second current, and the third current by applying an inverse Clarke transform to the output of the first current sensor and the output of the second current sensor.

A voltage-glitch detection and protection circuit and method are provided. Generally, circuit includes a voltage-glitch-detection-block (GDB) and a system-reset-block coupled to the GDB to generate a reset-signal to cause devices in a chip including the circuit to be reset when a voltage-glitch in a supply voltage (VDD) is detected. The GDB includes a voltage-glitch-detector coupled to a latch. The voltage-glitch-detector detects the voltage-glitch and generates a PULSE to the system-reset-block and latch. The latch receives the PULSE and generates a PULSE_LATCHED signal to the system-reset-block to ensure the reset-signal is generated no matter a width of the PULSE. In one embodiment, the latch includes a filter and a sample and hold circuit to power the latch, and ensure the PULSE_LATCHED signal is coupled to the system-reset-block when a voltage to the GDB or to the latch drops below a minimum voltage due to the voltage-glitch.

An analog fault detection circuit is disclosed. The analog fault detection circuit comprises an input terminal, an input circuit path coupled to the input terminal at a first end and a first sampling switch coupled to the second end of the input circuit path. The first sampling switch is configured to sample an input path voltage at the second end of the input circuit path to provide a first analog to digital converter (ADC) input voltage. The analog fault detection circuit further comprises a first ADC conversion circuit configured to convert the first ADC input voltage to a first digital ADC output; and a first broken wire detection circuit coupled between the first sampling switch and the first ADC conversion circuit, and configured to adaptively pulldown or pullup the first ADC input voltage, in order to detect a fault associated with a first analog circuit path.

A method and system for analyzing waveform capture data is provided. In one aspect, the method comprises receiving, by a controller from an intelligent electronic device, waveform capture data indicative of an electrical event, extracting, from the waveform capture data, electrical event data, extracting, from memory associated with the controller, additional data, classifying the waveform capture data into a category of a plurality of categories using the electrical event data, comparing the electrical event data and the additional data to stored data, diagnosing the electrical event and a cause of the electrical event based on the comparison and providing an indication of the cause of the electrical event.