To easily measure a voltage to ground of electromagnetic interference waves generated on a cable. A capacitance-to-ground measurement mechanism 10 includes a first electrode 11 and a second electrode 12 positioned at equal altitudes to be opposed to the earth, and a first voltage measurement device 15 to measure a voltage generated in a first resistance 14 connected between the first electrode 11 and the second electrode 12 by an output signal from an oscillation circuit 13. A voltage-to-ground measurement mechanism 30 includes a GND electrode 31 positioned at an altitude equal to that of the first electrode 11 and the second electrode 12 to be opposed to the earth, and a second voltage measurement device 33 to measure a voltage generated in a second resistance 32 connected between the GND electrode 31 and a probe 34 that is brought into contact with a cable core 106 as a measurement target. A computation mechanism 50 includes a computation device 51 to calculate a voltage to ground of electromagnetic interference waves generated on a cable based on data of respective voltages measured by the capacitance-to-ground measurement mechanism 10 and the voltage-to-ground measurement mechanism 30.

To easily measure a voltage to ground of electromagnetic interference waves generated on a cable. A capacitance-to-ground measurement mechanism 10 includes a first electrode 11 and a second electrode 12 positioned at equal altitudes to be opposed to the earth, and a first voltage measurement device 15 to measure a voltage generated in a first resistance 14 connected between the first electrode 11 and the second electrode 12 by an output signal from an oscillation circuit 13. A voltage-to-ground measurement mechanism 30 includes a GND electrode 31 positioned at an altitude equal to that of the first electrode 11 and the second electrode 12 to be opposed to the earth, and a second voltage measurement device 33 to measure a voltage generated in a second resistance 32 connected between the GND electrode 31 and a probe 34 that is brought into contact with a cable core 106 as a measurement target. A computation mechanism 50 includes a computation device 51 to calculate a voltage to ground of electromagnetic interference waves generated on a cable based on data of respective voltages measured by the capacitance-to-ground measurement mechanism 10 and the voltage-to-ground measurement mechanism 30.

Resistor voltage dividers are commonly used to create reference voltages, or to reduce the magnitude of a voltage so it can be measured. Many measurements in test and measurement or calibration applications regularly require accuracies within the sub-part per million (ppm) range, e.g. 0.1 ppm to 1.0 ppm. However, the continued drive for improved accuracy in calibration, standards, and measurements on circuits and components means many measurements and measurement systems are operating at 50 parts per billion (ppb) and below to approximately 10 ppb. At these levels even relatively simple passive elements such as voltage dividers cannot be used without calibration and that these calibrations may be required at frequencies substantially higher than the other elements within the test and measurement equipment. Accordingly, the inventors have established a self-contained voltage divider with internal calibration allowing the voltage divider to be calibrated for every measurement if necessary.

Resistor voltage dividers are commonly used to create reference voltages, or to reduce the magnitude of a voltage so it can be measured. Many measurements in test and measurement or calibration applications regularly require accuracies within the sub-part per million (ppm) range, e.g. 0.1 ppm to 1.0 ppm. However, the continued drive for improved accuracy in calibration, standards, and measurements on circuits and components means many measurements and measurement systems are operating at 50 parts per billion (ppb) and below to approximately 10 ppb. At these levels even relatively simple passive elements such as voltage dividers cannot be used without calibration and that these calibrations may be required at frequencies substantially higher than the other elements within the test and measurement equipment. Accordingly, the inventors have established a self-contained voltage divider with internal calibration allowing the voltage divider to be calibrated for every measurement if necessary.

An exemplary voltage sensor device includes at least one high voltage segment and at least one low voltage impedance element. In order to enhance the power dissipation due to impedances spread inside of the device body, the sensor device can be adapted or extended such that at least one high voltage segment, and at least one low voltage impedance element are arranged on an elongated insulating support with adaptive complementary mechanical and electrical interconnection elements on at least one end of the support element. The mechanical and electrical interconnection elements provide a manner of interconnecting at least two elongated insulating supports together in a pivotable way.

An exemplary voltage sensor device includes at least one high voltage segment and at least one low voltage impedance element. In order to enhance the power dissipation due to impedances spread inside of the device body, the sensor device can be adapted or extended such that at least one high voltage segment, and at least one low voltage impedance element are arranged on an elongated insulating support with adaptive complementary mechanical and electrical interconnection elements on at least one end of the support element. The mechanical and electrical interconnection elements provide a manner of interconnecting at least two elongated insulating supports together in a pivotable way.

A voltage sampling system is provided. The voltage sampling system includes a voltage sampling device, two optic-fiber transmission lines and a control device. The voltage sampling device includes a voltage-dividing resistor module, a common mode rejection circuit and an analog-to-digital converter. The voltage-dividing resistor module generates a first and a second divided voltages according to a voltage source. The common mode rejection circuit receives the first and the second divided voltages to perform a common-mode noise rejecting process to generate an output voltage. The analog-to-digital converter converts the output voltage to generate a digital data signal. The two optic-fiber transmission lines transmit the digital data signal and a clock signal respectively. The control device receives the digital data signal from the analog-to-digital converter and the clock signal to perform a digital data processing.

Method and apparatus for determining a ground fault impedance. In one embodiment the apparatus comprises a voltage divider and a ground fault detection module for (i) determining a first voltage based on at least one voltage measurement of the voltage divider while the voltage divider is coupled between the first AC line and the DC line; (ii) determining a second voltage based on at least one voltage measurement of the voltage divider while the voltage divider is coupled between the second AC line and the DC line; (iii) determining a differential voltage based on at least one voltage measurement between the first AC line and the second AC line; and (iv) computing the ground fault impedance based on the first voltage, the second voltage, and the differential voltage.

A memory system includes a connector through which power for the memory system is to be supplied from an external device, a controller, a nonvolatile memory device, a power source circuit connected to the controller and the nonvolatile memory device by power lines through which power is supplied to the controller and the nonvolatile memory device, and a power source control circuit that receives a supply of power from the external device through the connector and supplies the power to the power control circuit. The power source control circuit is configured to detect using a divided voltage of a voltage of the power supplied thereto, that the voltage of the power supplied thereto is higher than a predetermined voltage and interrupt the power supplied to the power control circuit if the voltage of the power supplied thereto is higher than the predetermined voltage.

A system and method for monitoring power lines comprises a plurality of sensory assemblies each connected to a phase of a power line and comprising a sensory transceiver that transmits a signal comprising a digital representation of a voltage wave and a current wave on a single phase of a power line. A common assembly comprising a common transceiver receiving the signal from each sensory transceiver and a microprocessor. A precision timing device directs the common transceiver to send signals to each of the sensory assemblies to synchronize the sensory assembly reading on a phase of a power line. The microprocessor for analyzing the timed signals synchronized for a plurality of phases by determining the net real time sum of the current of the plurality of phases to determine ground or neutral current and for determining instantaneous voltage between any two phases.