Abstract: The present invention relates to a multi-purpose battery charging circuit configuration able to be selectively in a simple charge mode when intended for low-end solutions (option 3) or in a charge-and-play mode when intended for medium- and high-end solutions (options 1 and 2 respectively), while maintaining the supply voltage of any portable and mobile electronic devices with an acceptable noise level. The selection will be made possible by the use of multiplexers (MUX1, MUX2). If the option 1 is chosen, the bi-directional switching device (210) will be controlled by a driver circuit (340) for allowing the current which flows through it towards the battery (20) to strongly increase and thereby maintaining the voltage across the circuitry (10) at a value slightly greater than the voltage across the battery (20).

Abstract: A battery charger for a portable electronic device includes a linear charger to generate a substantially constant current for charging the battery and a switching voltage regulator to convert power supplied by an external adapter to a supply voltage for the linear charger. A feedback circuit controls operation of the switching voltage regulator so that the voltage supplied to the linear charger is substantially equal to the combination of the battery voltage and the drain-to-source voltage of the linear charger. In this way, power dissipation by the linear charger is minimized without requiring the use of a high accuracy current limited adapter.

Abstract: A bi-directional inverter-charger including a bridge rectifier and DC-to-DC conversion components. The inverter-charger may be connected between an alternating current source, e.g., an AC line, and a direct current source, e.g., a battery pack. The DC-to-DC conversion components may include boost and buck circuits that are switchably configured between a charge mode and an inverter mode such that common components are used in both charge and inverter configurations. In the charge configuration, a full wave rectified signal from the H-bridge is up converted by the boost circuit, and the buck circuit controls charge current to the direct current source. In the inverter configuration, the boost circuit up converts the direct current voltage source, and the buck circuit controls the current and its form to the bridge circuit so that the bridge circuit may be connected directly with the AC source.

Abstract: A circuit for charging a battery pack includes a power converter and a charger controller. The power converter is operable for receiving an input power, and for providing a charging power for charging the battery pack. The power converter provides galvanic isolation between input circuitry and output circuitry of the circuit. The input circuitry shares a first ground potential with the input power, and the output circuitry shares a second ground potential with the charging power. The charger controller in the input circuitry includes a modulator for generating a driving signal to drive the power converter and control the charging power.

Abstract: A power supply circuit supplying power to a charge control circuit charging a secondary battery is disclosed. The power supply circuit includes a direct-current power supply configured to generate and output a predetermined voltage; and a DC-DC converter configured, to detect the voltage of the secondary battery, convert the predetermined voltage input from the direct-current power supply into a voltage according to the detected voltage of the secondary battery, and output the converted voltage to the charge control circuit.

Abstract: Methods, devices, and systems for charging a battery in a mobile device are provided. For example, in one embodiment, among others, a battery charging system includes a monitoring circuit configured to monitor a battery and generate a sense current. The battery charging system further includes a comparing circuit configured to compare a reference current and the generated sense current. The comparing circuit is further configured to generate a comparison signal. Also, the battery charging system further includes a control circuit configured to control a level of a charging current applied to the battery based on the comparison signal.

Abstract: A battery pack includes plurality of secondary battery cells, a voltage measurement module configured to measure a voltage of each of the plurality of secondary battery cells, a charge switching module configured to turn on and off a charge current to the plurality of secondary battery cells, a first judgment module configured to judge whether a highest voltage value measured by the voltage measurement module is equal to or greater than a predetermined value, and a charge stop module configured to turn off the charge switching module when the highest value is equal to or greater than a predetermined value.

Abstract: The power supply device contains a first auxiliary device and a first rectifier connected to a DC voltage source; a second auxiliary device that receives electric power via the first rectifier; a first DC/DC converter that uses the DC voltage source as an input source; an electricity storage device connected to an output terminal of the first DC/DC converter; and second DC/DC having an output terminal connected to the first rectifier, which uses the electricity storage device as an input source. When the DC voltage source has output voltage higher than a predetermined value, electric power is fed from the DC voltage source to the second auxiliary device and the electricity storage device is put on charge by the first DC/DC converter. When the output voltage gets lower than the predetermined value, the second DC/DC converter starts to operate, preventing decrease in voltage to be applied to the second auxiliary device.

Abstract: A portable apparatus includes a system configured to receive a system current and perform a function, a charging battery configured to be charged with a charging battery current and supply power to the system, and a power management circuit configured to receive an externally supplied power, supply the system current to the system, and supply the charging battery current to the charging battery based on a sensed level of the system current, wherein the charging battery current decreases in proportion to the system current.

Abstract: An alternator configured for use in a vehicle comprises a stator having a plurality of stator windings. A rotatable field coil is positioned adjacent to the stator within the alternator. A field driver circuit is configured to deliver an electric current to the field coil. A voltage sensor is configured to detect a battery voltage. A controller in the alternator is configured to execute either a first field current control program or a second field current control program depending at least in part upon the detected battery voltage. The first field current control program is configured to control the electric current delivered to the field coil in a 12 volt vehicle power system. The second field current control program is configured to control the electric current delivered to the field coil in a 24 volt vehicle power system.

Abstract: An electrical power system may comprise a main generator with a rotor having field windings and at least one embedded permanent magnet. A generator control unit (GCU) may be connected to receive excitation current produced by the main generator with flux from the at least one permanent magnet. An exciter generator may be connected to be provided with excitation from the GCU. The exciter generator may provide excitation current to the field windings of the main generator. The main generator may produce output current from flux from the field windings and the at least one permanent magnet.

Abstract: A device for controlling the voltage and the phase angle of a polyphase electric transmission network including an induction regulator that is connected between the primary side and the secondary side of the transmission network. A gap is provided with a magnetic layer having a relative permeability that is controllable, wherein the magnitude (amplitude) of the secondary voltage vector is also adapted to be controlled by controlling the permeability of the magnetic layer. The magnetic layer may include a magnetic fluid or a solid material.

Abstract: The present invention discloses a power converter with improved line transient, comprising: a power stage circuit including at least one power transistor switch which operates to convert an input voltage to an output voltage; an error amplifier comparing a feedback signal with a reference signal to generate an error signal; an input voltage instant variation extraction circuit extracting an instant variation of the input voltage and generating a signal relating to the instant variation; and a PWM comparator generating a PWM signal according to at least a ramp signal, the error signal, and the signal relating to the instant variation, to thereby control the operation of the power transistor switch in the power stage circuit.

Abstract: The invention presents a simple and high accuracy output current detect and control scheme to control the output current of the step up-down (Buck-Boost) and step up (Boost) switching converter, It makes step up-down (Buck-Boost) and step up (Boost) switching power converter operate in wide input voltage range and low in total BOM cost and the switching converter can be used as a controllable current source for several applications

Abstract: A power conversion assembly includes a conversion box, a conversion lead and a plurality of adapter plugs. The conversion box has a power regulation circuit, a variable switch, a power input port, a power output port and at least a interface port. The variable switch, the power input port, the power output port and the at least one interface port are connected with the power regulation circuit. When the conversion box is connected with the power adapter to obtain a DC power, a DC power with a different voltage can be sent out by the switching of the variable switch and the regulation of the power regulation circuit. One end of the conversion lead is used to receive the regulated DC power from the conversion box. The other end of the conversion lead can be replaced with the adapter plug having different specification to supply power to different power-requiring equipment.

Abstract: A single-inductor multiple-output power converter includes an inductor having a first terminal and a second terminal. The first terminal of the inductor is coupled to a power input terminal, and the second terminal of the inductor is switched to either of the first terminal of the inductor, multiple power output terminals, and a ground terminal. By switching the second terminal of the inductor between the first terminal of the inductor, the power output terminals, and the ground terminal, the power converter may provide multiple output voltages at the power output terminals respectively, in a less loss and thereby higher efficiency manner.

Abstract: An electronic device for switched mode DC-DC conversion is provided that includes a stage for sensing an output current causing a voltage difference between a first and a second node. The current sensing stage includes a comparator being capacitively coupled with a first input to the first node and with a second input to the second node for determining a magnitude of the output current.

Abstract: A method and apparatus for converting a DC voltage to a lower DC voltage, provides for conducting current from an input terminal, through an inductor to charge a capacitor connected to the inductor at an output terminal and to provide a varying range of load current from the output terminal, alternately switching the input terminal between a supply voltage and a ground potential to produce a desired voltage at the output terminal that is lower than the supply voltage, while providing the varying range of load current, and disconnecting the input terminal from both the supply voltage and the ground potential to reduce an increase in voltage at the output terminal caused by a substantial reduction in the load current, while current through the inductor adjusts in response to the reduced load current.

Abstract: A buck-boost power converter switches the switches thereof with a novel sequence and extends the switching periods of the switches to reduce the switching loss and conduction loss when the input voltage thereof approaches the output voltage thereof. The influence of the load current of the power converter on the duty thereof is taken into account to switch the power converter between modes at correct time points, so as to prevent the output voltage from being affected by the mode switching.

Abstract: A switch-mode DC/DC converter and a linear low drop out (LDO) DC/DC regulator are connected in parallel to drive a single load. Both regulators share a common voltage reference, feedback network, input supply and output such that the regulated voltage is identical during each mode of operation. During heavy loads the switch-mode regulator is in operation and the linear regulator is disabled for the highest efficiency possible. Conversely at light loads the linear regulator is in operation with the switch-mode regulator disabled, also maximizing the efficiency. Each regulator senses load current to automatically transition between the appropriate voltage regulators at fixed load current levels. The presented invention also includes a make before break transition scheme of the voltage regulators to minimize the voltage transients.

Abstract: Method and apparatus are disclosed for electronic simulation of a potentiometer, and for providing a potentiometric output voltage that is representative of a parameter. The invention also teaches a non-contact type of sensor apparatus producing an output voltage that is indicative of a value of a sensed physical parameter. Electrical characteristics of a potentiometer are simulated by implementing a novel combination of analog and digital circuit techniques. Some of these characteristics include low input current, wide power supply voltage range, and an output voltage range that includes the power supply voltages. The present invention also teaches a sensor comprising electronically simulated potentiometer circuitry and a non-contact sensing element.

Abstract: Embodiments of DC power related systems and methods are described generally herein. Other embodiments may be described and claimed.

Abstract: A method and apparatus are described for providing a current mirror type high voltage switching circuit (60) having a reference branch (M2, M3, R1) and a tracking branch (M1, M5), where the output peak current is limited by adding an additional branch (M4, M6) to the current mirror circuit which includes an additional mirror transistor (M4) and cascode transistor (M6), and where over voltage protection is provided by including a shut-off circuit (Q1, Q2) which turns “OFF” the cascode transistors (M5-M8) whenever the output voltage (Vout) exceeds the first reference voltage (Vbat) by a predetermined amount.

Abstract: A method and a device (MON) for monitoring plasma-discharges during a surface treatment process are described. In this process electrodes within a gaseous medium are provided with an alternating voltage (UHV) for generating plasma. The monitoring device (MON) has a detector device (M1) for detecting a measurement signal (I) generated by the alternating voltage (UHV) within the gaseous medium, separating means (M2) for separating signal components above a preset frequency and evaluating means (M3) for evaluating the resulting separated signal components by comparing them with at least one preset reference. Preferably the generating of the plasma is achieved by dielectric barrier discharge and the electric current penetrating the medium, especially the dielectric displacement current, is measured as the measurement signal (I).

Abstract: A measurement apparatus includes a moving average calculation section and a convergence judgment section. The moving average calculation section calculates a moving average by inputting a phase error between a phase of an input signal and a target phase, that is detected by a phase-locked loop circuit. The convergence judgment section judges that the phase-locked loop circuit is not converged when an absolute value of the moving average is equal to or larger than a first threshold value and judges that the phase-locked loop circuit is converged when the absolute value of the moving average is smaller than the first threshold value.

Abstract: A method is provided for indicating the useful service life of a gas filtration and purification system comprising steps of embedding two or more mass-responsive electronic sensors (e.g., surface acoustic wave devices) in a sorbent bed of a filtration cartridge, wherein the mass-responsive electronic sensors are coated with a non-conductive absorptive organic polymer; passing a gas containing a volatile chemical of interest through the filtration cartridge and in contact with the two mass-responsive electronic sensors; and measuring a difference in an electronic property between the two mass-responsive electronic sensors. In such a manner, the two mass-responsive electronic sensors act as internal references with respect to each other, thereby eliminating variations in temperature, interferents, pressure, and the like.

Abstract: A digital multimeter can be monitored from a remote location via an on-board light source such as a backlight LED. The digital multimeter has memory, a processor operatively coupled to the memory, a light operatively coupled to the processor and the memory and a light sensitive sensor operatively coupled to the machinery and positioned proximate the light. The processor is configured to produce a first data signal containing information about the machinery, which is then modulated by the light so that the light blinks between an on state and an off state. The sensor is configured to detect the light on state and the light off state and convert the received light into a second data signal representative of the first data signal.

Abstract: A current sensor is provided for non-invasively measuring electrical current in an electrical conductor. The current sensor includes a housing having a Hall effect device and circuitry for transmitting a signal indicative of the current flowing through the electrical conductor. The current sensor includes a base having a surface for supporting an electrical conductor. A magnetic shielding member is coupled to the surface to shield the Hall effect device from stray or external magnetic fields. A compliant member is coupled to the magnetic shielding member opposite the surface. The compliant member compresses to allow the current sensor to accommodate a large variety of electrical conductor sizes. The compliant member further acts to bias the electrical conductor against the Hall effect device.

Abstract: In an oscilloscope probe with a transistor amplifier constructed on a semiconductor substrate using integrated circuit technology, at least one part of the input-voltage divider is also constructed together with the amplifier using integrated-circuit technology on the semiconductor substrate.

Abstract: An electrical current sensor is disclosed having conducting coil portion and an insulating body portion, the conducting coil portion comprising a coil portion with one or more helical windings made of a wire conductor and encircling a central cavity. Adjacent windings are separated by a dielectrically effective gap, wherein the insulating body portion comprises a dielectric spacer comprising a helical gap maintaining protuberance configured for insertion in the central cavity of the windings such that the gap maintaining protuberance is at least partially inserted in the gap between windings.

Abstract: A speed sensor assembly comprises: a driveshaft with a driveshaft axis, a sensing portion of the driveshaft having an axial bore along the driveshaft axis and multiple axial slots radially spaced around the sensing portion that penetrate through the driveshaft into the axial bore; and at least one electromagnetic sensor with a magnetic circuit proximate the sensing portion of the driveshaft; wherein rotation of the driveshaft causes the slots in the sensing portion to sequentially pass through the magnetic circuit of the electromagnetic sensor, thereby causing a change in the reluctance of its magnetic circuit that induces the electromagnetic sensor to generate an output signal that is representative of the rotational speed of the driveshaft.

Abstract: Apparatus for detecting a passing magnetic article includes a peak detector providing a detector output signal that changes state when the magnetic field signal differs from a magnetic field tracking signal by more than a threshold offset amount. The threshold offset amount is dynamically variable in response to detection of a speed of rotation of the magnetic article and a peak-to-peak signal level of the magnetic field signal.

Abstract: Double modulation of a magnetoresistive sensor entails modulating both an excitation (e.g., voltage or current) applied to the sensor and a tickling magnetic field applied to the sensor. The excitation and magnetic field are modulated at different frequencies fc and ff, respectively. As a result of the double modulation, the sensor output spectrum includes a carrier tone (CT) at frequency fc and side tones (STs) at frequencies fc±ff. A baseline relation between CT amplitude and ST amplitude is determined (e.g., by measuring CT and ST amplitude while drift occurs in the absence of a sample). During sensor operation, raw ST measurements are corrected using corresponding raw CT measurements to provide corrected ST measurements as the sensor output.

Abstract: A sensor comprises a magnetic field source, at least one flux conducting soft magnetic element with at least one air gap and at least one magnetic field sensor located in the air gap and measuring a change of the magnetic field of the magnetic field source. The flux conducting soft magnetic element consists of 35% by weight?Ni?50% by weight, 0% by weight?Co?2% by weight, 0% by weight?Mn?1.0% by weight, 0% by weight?Si?0.5% by weight and 0.5% by weight?Cr?8% by weight and/or 0.5% by weight?Mo?8% by weight, wherein (Mo+Cr)?8, rest iron and unavoidable impurities.

Abstract: A magnetic sensor of rotary, linear, or curvilinear displacement using at least one permanent magnet and at least one magnetosensitive element, which can move with respect to one another. The magnet exhibits a direction of magnetization that varies continuously along the direction of displacement, with the exclusion of a diametral magnetization in the case of a rotary sensor.

Abstract: An induction detecting type rotary encoder includes: a stator; a rotor configured to be rotated with respect to a rotary shaft; a first transmitting coil; a second transmitting coil; a first receiving coil; a second receiving coil; a first magnetic flux coupling body; and a second magnetic flux coupling body. The first transmitting coil is disposed between the first and second receiving coils. A distance between the second transmitting coil and the rotary shaft is larger than that of the second receiving coil and the rotary shaft. The first magnetic flux coupling body forms a first track for causing a periodic change for each rotation. The second magnetic flux coupling body forms a second track for causing a periodic change for each rotation. The second magnetic flux coupling body has a pattern of which an inner peripheral side is substantially continuous in a circumferential direction.

Abstract: A pressure distribution detector is less influence by installation environment, that is, a pressure distribution detector that detection sensitivity or detection accuracy is less adversely affected even if the device is fitted not only to a flat surface but also a surface having an arbitrary shape such as a curved surface. The pressure distribution detector comprises a plurality of drive coils (1) provided on a substrate, a plurality of detection coils (2) electromagnetically coupled with the plurality of drive coils in pairs respectively, and a spacer (4) for keeping a constant distance between the plurality of drive coils and the plurality of detection coils, respectively. In order to vary the degree of electromagnetic coupling between the drive coil and the detection coil, a variable electromagnetic coupling (3) formed of a conductor or a magnetic body is provided movably adjacent to the drive coil and/or the detection coil.

Abstract: A vibration and condition monitoring system with true digital signal processing based design, with very limited analog based general signal conditioning and integrated specific sensor conditioning and sensor power supply options. The device supports direct connection of eddy current probe systems to the module, due to a built-in driver and linearization functionality. Linearization and compensation of a specific eddy current probe/cable system is done by measuring its far/infinite gap response. This response is then according to the invention recalculated into a linearization curve/transfer function. Specific sensor signal conditioning is not dependent on hardware, but only on embedded software (firmware). There is full sensor input support in an I.S. environment. Not only the common sensor input types from accelerometer, velocity sensor or eddy current probe system for both vibration and/or speed measurements.

Abstract: Testing an electrical component, the component including a printed circuit board (‘PCB’) with a number of traces, the traces organized in pairs with each trace of a pair carrying current in opposite directions and separated from one another by a substrate layer of the PCB, where testing of the electrical component includes: dynamically and iteratively until a present impedance for a pair of traces of the component is greater than a predetermined threshold impedance: increasing, by an impedance varying device at the behest of a testing device, magnetic field strength of a magnetic field applied to the pair of traces by the impedance varying device, including increasing the present impedance of the pair of traces; measuring, by the testing device, one or more operating parameters; and recording, by the testing device, the measurements of the operating parameters.

Abstract: An eddy-current flaw detection device comprises a magnetic element group of which a specified number of magnetic elements are evenly spaced in each of at least two rows around the surface of a column shaped casing that can be inserted into a conductive pipe, with one row being located at a different position from the other row by ½ the even spacing in the row direction, and switching circuits for switching the magnetic elements in the respective row at time-division. The elements of one row function as magnetic field excitation elements, the elements of the other row function as magnetic field detection elements, and the eddy-current flaw detection device performs eddy-current flaw detection of the conductive pipe by detecting magnetic field excited by magnetic field excitation element by two magnetic field detection elements located at different positions from the magnetic field excitation elements by 3/2 the even spacing.

Abstract: A magnetic field sensing device comprising at least one magnetic sensor attached to a base structure, rotating member; and at least one flux concentrator mounted on the rotating member; whereby as the rotating member turns, the at least one flux concentrator shields the magnetic sensor so as to modulate the output of the at least one magnetic sensor. A second embodiment comprises a rotating member that rotates about an axis with at least one flux concentrator positioned thereon having a longitudinal axis in the radial direction of the rotating member; and at least one vector-type magnetic sensor fixedly mounted in the near proximity to the axis of the rotating member such that the magnetic field detected is modulated due to the rotation of the rotating member. Optionally, at least one fixed flux concentrator may be positioned along the periphery of the rotating member so as to increase magnetic flux input.

Abstract: A magnetic detector includes a detecting section having a surface facing a magnetic body which moves and emits a magnetic flux. The detecting section includes plural magnetic sensors for detecting the magnetic flux. The magnetic sensors are arranged in a matrix form having three or more rows and three or more columns arranged along the surface of the detecting section. The magnetic detector provides an input device precisely detecting a moving direction and a moving amount of the magnetic body.

Abstract: A detection system (100, 150) for qualitative or quantitative detection of a magnetic field property of a modulated magnetic field is described. The modulated magnetic field may e.g. stem from an adjacent electrical current (Iadj) or magnetic particles. The detection system (100, 150) comprises at least one magneto resistive sensor element (102), a current controller (104) for providing a sensing current (Isense) flowing through the magnetic sensor element (102) and a controlling means (108). The controlling means (108) is adapted for deriving at a first frequency f1 a temperature-related parameter of the at least one magneto resistive sensor. The controlling means (108) furthermore is adapted for deriving a qualitative or quantitative characteristic of the adjacent electrical current (Iadj) or magnetic particles, taking into account the derived temperature-related parameter. This second frequency (f1) is different from the first frequency (f1}). The invention also relates to a corresponding method.

Abstract: A method and apparatus for detecting the presence of magnetic beads is disclosed. By providing both a static magnetic field and a magnetic field that alternates in the MHz range, or beyond, the bead can be excited into FMR (ferromagnetic resonance). The appearance of the latter is then detected by a magneto-resistive type of sensor. This approach offers several advantages over prior art methods in which the magnetic moment of the bead is detected directly.

Abstract: Methods and apparatuses for magnetic resonance imaging (MRI) and/or magnetic resonance spectroscopy comprising a superconducting main magnet operable to generate a uniform magnetic field in an examination region, at least one superconducting gradient field coil operable to apply a respective at least one magnetic field gradient within the examination region, and at least one RF coil that is operable to transmit and receive radio frequency signals to and from the examination region, and that is configured for cooling and comprises at least one of (i) a non-superconducting material that when cooled to a temperature below room temperature has a conductivity higher than that of copper at that temperature and (ii) a superconducting material. The main magnet, the gradient coils, and each of the at least one RF coil of a given system may each be implemented as high temperature superconductor materials.

Abstract: Methods (2900), apparatuses (3000), and computer program products for segmenting an infarct in a diffusion-weighted imaging (DWI) volume are disclosed. A Region of Interest in at least one slice of the DWI volume is selected (2912). The ROI comprises at least a portion of the slice. A threshold for a minimum size of an infarct region is selected (2916). An energy mask is convolved (2918) with that slice, and the resulting energy image is normalized (2920). The ROI in the convolved energy image is selected (2922). An initial threshold is determined (2924) using a histogram of the ROI of the slice without a background region, and an initial segmentation of the slice is performed (2926). Individual components of the initial segmentation of the slice are labeled (2930). A final threshold is determined (2932) using histograms of labeled components if the initial segmentation, and a final segmentation if the slice is performed (2934) using that threshold.

Abstract: In a magnetic resonance (MR) method and apparatus for the acquisition of a first image data set and a second image data set of an examination subject, a series of excitation pulses is radiated into the examination subject, and after each excitation pulse, a first echo signal is detected after a first echo time TE1 and a second echo signal is detected after a second echo time TE2, with TE2 greater than TE1, and the first echo signal is entered in a first raw MR data set and the second echo signal is entered in a second raw MR data set. A first image data set is acquired from the first MR data set on the basis of magnitude information contained in the first MR data set. A second image data set is acquired from the second MR data set on the basis of phase information contained in the second MR data set. The first and second image data sets are stored on at least one memory device.

Abstract: A method for producing a magnetic resonance image using an ultra-short echo time. The method includes applying a pulse sequence to an object, detecting a spirally encoded and phase encoded magnetic resonance signal associated with the object, and reconstructing the magnetic resonance image based on the spirally encoded and phase encoded magnetic resonance signal. The pulse sequence includes a slab-selective radiofrequency pulse, a slab-selective gradient pulse, a plurality of variable duration slice encoding gradient pulses, a plurality of first spiral encoding gradient pulses, and a plurality of second spiral encoding gradient pulses. The detection of the spirally encoded and phase encoded magnetic resonance signal occurs concurrently with the application of one of the plurality of first spiral encoding gradient pulses and with the application of one of the plurality of second spiral encoding gradient pulses.

Abstract: A magnet arrangement for generating an NMR-compatible homogeneous permanent magnetic field is described. The invention has two permanent magnets, referred to hereafter as main magnets, which each have a magnet pole surface area. The magnet pole surface areas are situated parallel and at a distance to one another, so that the main magnets define an interspace on both sides through their magnet surface areas. The magnet pole surfaces of the main magnets each have a magnetic polarization opposite to one another. At least two annular permanent magnets are used, which are referred to hereafter as ring magnets, are situated coaxially to one another and jointly radially bound a ring inner chamber. The ring magnets are situated relative to the two main magnets in so that the ring inner chamber at least regionally encloses the interspace, and the magnetic fields of the main and ring magnets are constructively superimposed.

Abstract: A drill string is disposed in the borehole having a BHA and a drill bit advancing the borehole. Among other BHA components, including a telemetry unit and a data acquisition unit, in a surface-to-borehole configuration a receiver (or receiver array) is positioned immediately proximate the drill bit in the borehole, while a source (or source array) is positioned at the Earth's surface. Alternatively, in a borehole-to-surface configuration the source may be positioned immediately proximate the drill bit in the borehole while a receiver (or receiver array) is positioned at the surface. The surface-to-borehole, or borehole-to-surface, system enables an electromagnetic look about while drilling operations are underway.