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.

Embodiments of the present disclosure relate to a multi-function circuit. The circuit comprises a low side circuit that is comprised with a first set of enhancement mode transistors. The half bridge circuit also includes a high side circuit that is comprised of a second set of transistors. Each of the enhancement mode transistors of the first set and second set of enhancement mode transistors are Gallium Nitride (GaN) transistors. In some embodiments, the GaN transistors are High Electron Mobility Transistors (HEMTs). In additional embodiments, the GaN transistors are configured and operated as saturated switches. In further embodiments, the half bridge circuit is designed as a discrete circuit. Additionally, each of the first set and second set of transistors, diodes, resistors, and all passive elements are discrete components arranged to form a half bridge circuit. In fact, the entire half bridge circuit is built from discrete components.

An adapter for a current probe is described, said adapter being configured to be connected with said current probe. Said adapter enables a voltage measurement by using said adapter and said current probe. Said adapter comprises a current loop and at least one transconductance unit. Said transconductance unit transforms the voltage to be measured into a current wherein the current obtained is forwarded by said current loop. Further, a testing system is described.

The present disclosure provides a voltage detector capable of alerting a worker to nearby presence of a voltage source regardless of the worker's awareness simply by being worn on the worker's body. In a voltage detector for detecting approach to a voltage source, a voltage induced in a human body due to approach to a voltage source is measured by a first electrode of a detection circuit, a voltage to ground is measured by a second electrode of the same circuit, the detection circuit captures a current generated due to a difference between an electric potential of the first electrode and an electric potential of the second electrode, and output from the detection circuit is displayed for warning when the human body insulated from the ground approaches the voltage source.

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 voltage-current sensor enables more accurate measurement of the voltage, current, and phase of RF power that is delivered to high-temperature processing region. The sensor includes a planar body comprised of a non-organic, electrically insulative material, a measurement opening formed in the planar body, a voltage pickup disposed around the measurement opening, and a current pickup disposed around the measurement opening. Because of the planar configuration and material composition of the sensor, the sensor can be disposed proximate to or in contact with a high-temperature surface of a plasma processing chamber.

A voltage measurement system has a voltage measuring device connected to a device under test by a voltage divider to drop high voltages (e.g., peaking at or above 100 kilovolts) at a measurement point to lower levels for processing by a voltage measurement and wireless printed circuit board. The voltage measuring device communicates raw measurement data wirelessly (e.g., via Bluetooth) to a remote device such as a mobile phone, laptop or portable meter head having a display and processing device programmed to calculate voltage measurements such has absolute average (ABS AVG), AC root mean square (RMS), +/peak voltage, and AC or DC coupling. The remote device can wirelessly communicate with multiple voltage measuring devices to capture raw measurement data therefrom for voltage measurement applications with multiple measurement points (e.g., three-phase measurement, and transformer testing).

Systems and methods provide a portable, verified voltage source that allows safe testing of separate non-contact voltage measurement systems. A proving unit of the present disclosure provides a known or specified alternating current (AC) voltage output across an insulated wire, which AC voltage may be fixed or may be user-selectable through a suitable user interface. The proving unit may include a visual indicator and/or an audible indicator that provides the user with an indication confirming that the proving unit is supplying an output voltage with the specifications of the proving unit, so the user will know that the proving unit is operating normally and is ready for testing a non-contact voltage measurement system. If the proving unit cannot provide the specified voltage output, the indicator(s) provides a signal to the user that the proving unit is currently non-functional. The proving unit may additionally verify contact voltage measurement systems (e.g., DMMs).

A method for nondestructive inspection of ceramic structures present as either a ceramic matrix composite structure or a ceramic based coating. Such non-metallic structures are used to provide thermal protection or weight reduction or both to aircraft and their components. The nonmetallic structure is scanned with an electromagnetic pulse in the range of 200 GHz to 4 THz. The electromagnetic pulse includes a plurality of frequencies within the Terahertz range and is not restricted to a single designated frequency. The frequency range is sensitive to changes in impedances and refractive index within the structure. After the electromagnetic pulse passes through the nonmetallic structure, it may be evaluated for changes in impedance in the nonmetallic structure at different locations, and, when present, whether the changes in impedance impact the ability of the structure to perform the function for which it was designed.

Improved devices, apparatuses, systems, and methods involving the use of field probes with voltage-controlled variable impedance elements and surface-launched acoustic wave devices, including surface acoustic wave (SAW) devices and SAW sensor-tag wireless interface devices to measure voltage and current in current carrying conductors (CCCs) via measurement of the electric fields and magnetic fields around said CCCs are disclosed. The devices, apparatuses, systems, and methods taught in the present invention include a remotely powered line-mounted measurement unit that requires no connection to electrical ground for operation, and that has no internal energy source, no energy harvesting or power conditioning circuitry, no discrete energy storage components, and no radio. The devices, apparatuses, systems, and methods taught in the present invention also provide for determining the phase (leading or lagging) of the current relative to the voltage in AC power systems, and also provide for measurement of temperature of the conductor.