Current transducers are widely used in current measuring systems. They provide good isolation between the supply voltage and the measurement equipment. However they can introduce small phase errors which can become significant sources of error if the current to a load is out of phase with the supply voltage for the load. This disclosure discusses a robust measurement apparatus and method that can be used in situ to monitor for and correct phase errors.

The invention involves a multimeter with a meter probe module and phasing probe module capable of wireless communication, proximity measurements, and accurately reading phase degrees. The meter probe module and the phasing probe module can communicate wirelessly, via a wired cable interface, or any combination thereof. The meter probe module and phasing probe module have unique radio frequency serial numbers that allow the probe modules to only communicate with its paired partner probe module while ignoring all other probe modules. The multimeter has a measurement point capable of taking direct contact measurements. The multimeter also has a measurement point capable of taking a voltage measurement without directly contacting the object to be measured. This is accomplished by taking voltage readings from the electric field of the air surrounding said object. The improved multimeter may allow an operator to more safely gather accurate information about an object being measured.

A high voltage phasing voltmeter comprises first and second probes. Each probe comprises an electrode for contacting a high voltage electrical conductor. The electrodes are connected in series with a resistor. A meter comprises a housing enclosing an electrical circuit for measuring true rms voltage. The electrical circuit comprises an input circuit for connection to the first and second probes and developing a scaled voltage representing measured voltage across the electrodes. A converter circuit converts the scaled voltage to a DC signal representing true rms value of the measured voltage. A peak hold circuit is connected to the converter circuit to hold a peak value of the true rms value. A display is connected to the peak hold circuit for displaying the peak value of the true rms value.

A detecting apparatus for AC motor malfunction by using a current delay property of an AC motor and outputting a malfunction signal to an alarming device is presented. The detecting apparatus for AC motor malfunction includes a voltage phase delay setting unit, a voltage phase conversion unit, a current phase detecting unit, a current phase conversion unit, a phase comparator, a sawtooth wave generating unit, a phase difference detecting unit, a phase shift bandwidth setting unit, a noise filtering unit, and a malfunction signal output unit.

The invention provides a method and system for precisely measuring AC power and detecting load impedance using a precise analog front-end, zero-crossing detectors, and a phase detection system capable of extracting precise phase information from the sensed voltage and current measurements. More particularly, the invention provides an apparatus, comprising a transmit circuit configured to generate a wireless field via an antenna for transferring charging power to a receiver device, for determining a phase difference between a first signal and a second signal. The apparatus further comprises a phase detection circuit to output a phase signal indicating a duration of a phase offset between a time-varying voltage and a time-varying current of the transmit circuit. The apparatus further comprises a capacitor configured to receive a variable current from a current source for the duration of the phase offset between the time-varying voltage and a time-varying current.

A control unit for a food waste disposer has a controller that determines operational status of the food waste disposer based on motor loading of an induction motor of the food waste disposer.

In known methods for through-cut detection in the thermally assisted through cutting of a workpiece, the workpiece is subjected to a first alternating signal. Starting therefrom, to indicate a method which allows a fast and accurate detection of a through-cut made, it is suggested according to the invention that the method comprises the following method steps:

a) detecting a second alternating electrical signal caused by the first alternating electrical signal in a measurement electrode spaced from the workpiece,

b) determining the phase shift between first and second alternating electrical signal with output of a phase shift signal,

c) detecting a temporal evolution of the phase shift electrical signal or a measurement variable derived therefrom in a predetermined time interval,

wherein a workpiece through-cut made is detected in that the phase shift signal or the measurement variable derived therefrom is in the time interval within a predetermined fluctuation range.

A phase frequency detector (PFD) includes a first circuit portion and a second circuit portion. The first circuit portion receives a reference signal and activates a first error signal if the phase of the reference frequency leads the phase of a feedback signal. The second circuit portion receives the reference and activates a second error signal if the phase of the reference frequency lags the phase of the feedback signal. The first circuit portion is powered by a first power supply, and the second circuit portion is powered by a second power supply. A PLL implemented using the PFD generates a frequency output with minimized jitter.

The present application presents a solution that intends to solve the problem of providing a single-stage bidirectional power conversion system (PCS) with a controllable power factor and the capability to regulate the current in the DC side. Disclosed is a single-stage, bidirectional and high-frequency isolated PCS, comprising a high-frequency transformer (HFT), a three-phase-to-single-phase matrix converter (MC), a full-bridge (FB) AC to DC converter, and a control system, where the control system outputs are connected to the switches of the MC and the FB converter. Moreover, the PCS output can also form a DC network for energy supply of several devices. This system converts three-phase AC power input from the network into DC power output that can be used for example to charge an energy storage device or supply a direct current distribution system. It is also possible to convert DC power input into AC power output to supply the network.

A harmonic distortion separation method, nonlinear character determination method, apparatus and system where a phase difference between an inherent harmonic and a generated harmonic is determined by using multiple groups of input power, output power and fundamental magnitudes of a memoryless nonlinear transfer function of a nonlinear model of a system to be measured, and power of a harmonic generated by the system to be measured is separated by using the phase difference. In an embodiment, the phase difference between the inherent harmonic and the generated harmonic is first determined by using an assumption that a model coefficient is a constant according to the set nonlinear model, then the harmonic separation is performed by using the phase difference, and the power of the harmonic generated by the system to be measured is calculated.