49 results about "Ac field" patented technology

Electrically powered electromagnetic field source beacons installed in a reference well in combination with a down-hole measurement while drilling (MWD) electronic survey instrument near the drill bit in the borehole being drilled permit distance and direction measurements for drilling guidance. Each magnetic field source beacon consists of a coil of wire wound on a steel coupling between two lengths of steel tubing in the reference well, and powered by an electronic package. Control circuitry in the electronic package continuously “listens” for, and recognizes, a “start” signal that is initiated by the driller. After a “start” signal has been received, the beacon is energized for a short time interval during which an electromagnetic field is generated, which is measured by the MWD apparatus. The generated magnetic field may be an AC field, or switching circuitry can periodically reverse the direction of a generated DC electromagnetic field, and the measured vector components of the electromagnetic field are used to determine the relative location coordinates of the drilling bit and the beacon using well-known mathematical methods. The magnetic field source and powering electronic packages may be integral parts of the reference well casing or may be part of a temporary work string installed therein. Generally, numerous beacons will be installed along the length of the reference well, particularly in the important oil field application of drilling steam assisted gravity drainage (SAGD) well pairs.

Electrostatic system is for optimal charging of aerosols and particulates. In order to improve their collection, the system uses a combination of DC field and AC fields produced by multiple AC electrodes. The system minimizes the size and power consumption of the device, as well as increasing the collection efficiency.

Methods of detecting anomalies in ambient alternating current (AC) fields are provided. An exemplary embodiment of such a method includes the steps of placing an AC field sensor in an ambient AC field, generating a signal representative of the ambient AC field received by the sensor, and processing the signal to determine if the ambient AC field includes any anomalies. Various applications for the methods are also provided.

Methods for detecting and classifying loads on alternating current (AC) lines are provided. One such method includes the steps of placing an AC field sensor in AC electric and magnetic fields generated by an AC line, generating an electric field signal representative of the AC electric field received by the AC field sensor, generating a magnetic field signal representative of the AC magnetic field received by the AC field sensor, generating a relative phase signal representative of relative phase changes between the electric and magnetic fields, and processing the relative phase signal to detect and classify loads on the AC line. In another method, relative load vector signals representative of relative magnitude and phase changes in the magnetic field are generated and processed to detect and classify loads on the AC line.

Method for nondestructive and noncontact detection of faults in a test piece, with a transmitter coil arrangement with at least one transmitter coil that transmits periodic electromagnetical AC fields to a test piece, a receiver coil arrangement with at least one receiver coil for detecting a periodic electrical signal having a carrier oscillation whose amplitude and / or phase is modulated by a fault in the test piece. A signal processing unit produces a useful signal from the receiver coil signal, and an evaluation unit evaluates the useful signal to detect a fault in the test piece. A self-test unit undertakes systematic quantitative checking of signal processing functions of the signal processing unit and / or of the transmitter coil arrangement and / or of the receiver coil arrangement and / or upon external request undertakes calibration of the signal processing unit using a calibration standard which replaces the transmitter coil arrangement and / or of the receiver coil arrangement.

The tandem differential mobility spectrometer (DMS)-ion modulator instrument provides improved resolution relative to traditional DMS for molecules with larger masses. The instrument includes an ion-bunching electrode with an AC field synchronized to the transit time of the ion flow which is positioned downstream of a DMS. The ion bunching electrode produces a mobility-dependent modulation of the ion current. The ratio of AC to DC current provides a measure of the mobility of a large ion, even if it has little differential mobility, thereby extending the useful range of mobility characterization of a DMS system. The instrument is more compact than a larger traditional ion mobility spectrometer and does not require high voltages or high frequencies. Modulation before DMS separation or between tandem DMS separations produces a variable range of analyte and reactant ion densities as well as spatially separating negative and positive ions to reduce ion recombination.

The present invention provides a matrix-based method for automatically judging the logic of the last circuit breaker, which includes the following steps: Step 1, establishing the AC field topology matrix; Step 2, constructing the connectivity matrix; Step 3, constructing the node attribute matrix; Step 4, calculating the AC field Field state matrix; step 5, criterion: step 51, when satisfying that there is an element equal to X in any row in the AC field state matrix, and the row contains an element equal to Y and an element equal to Z; step 52, obtaining the judgment The new AC field state matrix corresponding to the open circuit breaker interval; Step 53, when not satisfying that there is an element equal to X in any row in the new AC field state matrix, and this row contains an element equal to Y and an element equal to Z element, the disconnected breaker interval is the last breaker. The invention has the advantages of convenient modification, time-saving and simple maintenance, and is conducive to timely restoration of electricity at the production site.