The present invention relates to a supply voltage detection device (1), in particular for at least one load, for monitoring a rectified mains voltage of a mains voltage supply (2) and for comparing a detected mains voltage value with a predetermined reference value, wherein, if the detected mains voltage value is lower than the reference value, switching to e.g. an emergency voltage of an emergency voltage supply can be effected by means of an electronic control system (3). In addition, if a voltage limit value has been exceeded, the rectified mains voltage can be fed to an optocoupler (4) and a signal can be transmitted by said optocoupler for the duration of this excess, a duty factor that is dependent on the mains voltage value being determinable from the duration and the period of said signal.

Electrical voltage detection circuit and methods for determining the presence or absence of voltage in electrical equipment. An isolated power supply provides power to one or more voltage detection devices configured to detect voltage on one or more busses of electrical equipment. A switch is configured to provide supply voltage from the isolated power supply to the one or more busses of electrical equipment when the switch is closed. The voltage detection devices may determine if the one or more busses of electrical equipment are de-energized by detecting the voltage on the busses when the switch is open. The integrity of the electrical equipment may be verified by detecting, with the voltage detection devices, the voltage on the busses when the switch is closed, where the expected voltage readings are based on voltages being provided to one or more busses by the isolated power supply.

An absence of voltage indicator has an isolation circuit, an FM modulator attached to the isolation circuit, a reference oscillator, and a mixer attached to the reference oscillator and the FM modulator, wherein the output of the mixer is the difference of the two signals. In one embodiment, the FM modulator includes a variable capacitor which varies in response to a voltage in parallel to a fixed capacitor and an inductor in parallel to the capacitors.

A measurement correction method and apparatus for a sensor, and a server power supply. The method is applied to a sensor comprising a shunt resistor and a differential amplifier, and comprises: performing compensation verification on the sensor in advance to obtain a compensation coefficient of the sensor (S1); obtaining a voltage signal output by the sensor (S2); and correcting the voltage signal according to an error value of the shunt resistor and the compensation coefficient to obtain a voltage correction signal for use in system optimization management (S3).

Systems and methods for calibrating a voltage measurement device are provided herein. The voltage measurement device generates a reference current signal and senses the reference current signal in a conductor under test. A calibration system may control a calibration voltage source to selectively output calibration voltages in a calibration conductor. The calibration system may obtain data from the voltage measurement device captured by the voltage measurement device when measuring the calibration conductor. Such data may include one or more reference current measurements, one or more voltage measurements, etc. The calibration system utilizes the obtained measurements to generate calibration data which may be stored on the voltage measurement device for use thereby during subsequent operation. The calibration data may include one or more lookup tables, coefficients for one or more mathematical formulas, etc.

In one embodiment, a power supply comprises: a conversion circuit that outputs an output voltage at a first end of a cable; a remote voltage sensor measures a load delivered voltage from a second end of the cable; a control logic, wherein the power conversion circuit regulates the output voltage based on a signal from the control logic; a current sensor that measures current flow through the cable; and a resistance measurement circuit that computes a resistance of the cable as a function of the load delivered voltage, the current flow and the output voltage. The control logic regulates the load delivered voltage based on a voltage drop calculated utilizing the resistance. The control logic detects a change in the resistance of the cable based on the load delivered voltage and dynamically updates a value of the resistance for calculating the voltage drop when the change exceeds a tolerance.

A non-contact voltage and ground detector allows a user to easily analyze the ground or neutral port of an electrical component. The detector includes a tubular body, a metal probe, a power source, a ground-and-neutral detector mechanism, and a non-contact voltage device. The metal probe is concentrically and terminally mounted to the tubular body and acts as the physical engaging element. The power source provides the electrical energy for the detector and is mounted within the tubular body. The ground-and-neutral detector mechanism in conjunction with the metal probe set up an open circuit. The ground-and-neutral detector registers the quality of a ground or neutral when the metal probe with an external electrical element. The non-contact voltage device measures changes in magnetic fields about an electrical component to identify the presence of voltage within the electrical component.

A device for measuring voltage across a remote load includes a power supply configured to output a first output voltage to the remote load. A switch is selectively movable from a closed position to an open position. A measuring circuit measures a load voltage across the load when the switch is in the open position and determines a voltage difference between the first output voltage and the load voltage. The measuring circuit adjusts the first output voltage to a second output voltage to compensate for the voltage difference. A second A/D converter can also be coupled to the power supply. The second A/D converter measures a voltage across a resistor such that a change in the voltage indicates a change in the load voltage. The power supply is then adjusted to output a second output voltage to compensate for any change in load voltage.

An absence of voltage indicator has an isolation circuit, an FM modulator attached to the isolation circuit, a reference oscillator, and a mixer attached to the reference oscillator and the FM modulator, wherein the output of the mixer is the difference of the two signals. In one embodiment, the FM modulator includes a variable capacitor which varies in response to a voltage in parallel to a fixed capacitor and an inductor in parallel to the capacitors.

An arrangement for determining a magnitude of an electrical current flowing through a busbar. The arrangement has a measurement conductor which is electrically connected at a first contact point to the busbar and which extends from the first contact point to a second contact point. A third contact point is located on the busbar at a spacing distance from the first contact point. A voltage measurement device is configured to measure a voltage between the second contact point and the third contact point. The arrangement also has a controlled current source which is configured to introduce a measurement current into the measurement conductor.