Abstract: An organic electroluminescent (EL) display, wherein fabrication is simplified, manufacturing cost is reduced, periodicity with which pixels are arrayed is maintained, picture quality is prevented from deteriorating due to a boundary between transparent substrates, and high resolution is realized. A plurality of organic thin film EL display elements are formed on a single transparent substrate. Circuit substrates on which driver circuits for supplying signals to signal and scanning electrodes for each of the EL display elements are mounted are bonded to the EL display elements. The circuit substrate has an end-sealing property and through holes are bored opposite the signal and scanning electrodes. The through holes are covered by a conductive, end-sealing material. Signals are supplied from the driver circuit to the signal and scanning electrodes through the conductive material. A portion of the organic EL display element that is not bonded to the circuit substrate is covered by an end-sealing material.

Abstract: An apparatus and method for driving a gas discharge lamp, and in particular for dimming fluorescent lamps or tubes. An electronic circuit for controlling a gas discharge lamp is connected to an electrical power source and generates a high frequency pulse train that is applied to the electrodes of the lamp to light the lamp. A choke limits the current drawn by the lamp. A first series of pulses is produced and independent from this a second series of pulses is produced independently from the first, the first and second series of pulses being combined additively to produce the high frequency pulse train.

Abstract: A high pressure lamp is driven with a pulse width modulated, alternating current pulses having an absolute value that is substantially constant and a short term average that varies approximately sinusoidally.

Abstract: A simple, low-cost ballast circuit for adjusting the lumen output of a gas lamp. A number of ballast circuits are provided for a gas lamp, such as a fluorescent lamp. Specifically, a variable resistor is provided in each of the ballast circuits. The variable resistor is included in the resonant control circuit to adjust the switching frequency of the ballast circuit, thereby controlling the lumen output or brightness of a gas lamp. Additional components, such as a fixed resistor or an inductor may be added to the ballast circuit to limit the maximum switching frequency.

Abstract: In a circuit arrangement and a method for generating a high voltage for example for the operation of a plasma, comprising an impedance converter and a transformer including a primary coil and a secondary coil, by which the high voltage is provided, bridging switch members are arranged in the circuit and one of the primary and the secondary coil is short-circuited when a discharge occurs until the discharge is completed.

Abstract: To prevent lamp extinction during dead time of an inverter circuit of a full bridge system, to reduce delays of the rising time and the falling time of rectangular waves which have been output by the inverter circuit and to prevent formation of a phenomenon of momentary darkening of the radiant light, the discharge lamp is operated with an alternating current with rectangular waves which is produced by an inverter circuit of a full bridge system. When the inverter circuit of the full bridge system is driven a dead time is taken in which all switching devices are turned off. In the rear stage of the inverter circuit of the full bridge system, there is an inductance. The value of the inductance is fixed such that LL≧VL/IL·Td (VL being the luminous voltage of the discharge lamp, IL being the current and Td the dead time). Current can flow in the discharge lamp during the dead time by the energy stored in this inductance.

Abstract: The invention relates to a light source unit control method and a light source control unit, and a light source unit comprising a filament lamp with a characteristic of having a light quantity changing almost in proportion to a control voltage, which includes: a current detection sensor connected in series to the lamp; a multiplication circuit for generating a voltage Vw proportionate to the product of a terminal voltage V of the lamp and an output voltage V1 of the current detection sensor; a square root circuit for generating a voltage V2 proportionate to the square root of the control voltage V1; an error amplifier circuit for controlling an error to the minimum by comparing the output voltage Vw of the multiplication circuit and the output voltage V2 of the square root circuit; and a constant voltage power source unit for supplying an electric power to the filament lamp, the unit being connected to an output terminal of the error amplifier circuit, wherein the light quantity of the lamp is controlled by c

Abstract: A discharge lamp lighting apparatus which can prevent an increase of loss and a rise of temperature in the area where discharge lamp tube voltage is low. A power conversion circuit converts the input power Pin to output the DC power Pd. A discharge lamp driving circuit converts the DC power Pd supplied from the power conversion circuit to output AC voltage Vo and AC current Io. A controller provides constant power control for maintaining the AC power Po provided by the AC voltage Vo and AC current Io to be constant when the AC voltage Vo is higher than the predetermined value V1, and provides power reduction control for reducing AC power Po to the power conversion circuit when the AC voltage Vo is lower than the predetermined value V1.

Abstract: The present invention provides a cathode ray tube which exhibits a favorable contrast by enhancing a speed modulation effect. A front-stage anode electrode and a focus electrode which constitute an electron gun are respectively divided into a plurality of portions. A plurality of portions of the divided front-stage anode electrode are arranged in the tube axis direction at given intervals and are electrically connected with each other. A plurality of portions of the divided focus electrode are arranged in the tube axis direction at given intervals and are electrically connected with each other. Due to gaps formed in the front-stage anode electrode and the focus electrode, the speed modulation effect is increased.

Abstract: The invention concerns a light deflection device, and a control method for the light deflection device, which are rich in expandability of drive control. The light deflection device includes a polygon mirror to reflect the light beam; a rotor, having a magnet, to rotate the polygon mirror attached to the rotor; a stator on which a plurality of drive coils are fixed so as to generate a rotational force; and a plurality of connecting ports through which the plurality of drive coils are electronically coupled to a plurality of drive circuits, each of which drives the drive coils while controlling the rotational force to be generated between the magnet and drive coils. One of the drive circuits controls the rotational force during a start-up operation and a steady-rotating operation of the rotor, while another one controls the rotational force during a decelerating operation of the rotor.

Abstract: A device for supplying energy by means of a first DC voltage source e.g. in the form of a DC voltage bus, a drive system comprising several electric motors is connected to said DC voltage bus. The electric motors are comprised e.g. in a number of yarn feeding devices co-acting with a weft insertion system in a shuttleless weaving machine for producing a woven fabric having a multi-colour pattern. The electric motors operate with energy consumption function phases (start and acceleration) and with energy generating function phases (deceleration or braking). The first DC voltage source is associated with at least one second DC voltage source via a variable voltage converter.

Abstract: A speed-control drive circuit for a D.C. brushless fan motor includes a pulse width modulation input end for receiving an external pulse width modulation signal for controlling (and changing) the motor speed, and a motor winding drive circuit. The motor winding drive circuit and the pulse width modulation input end are connected to a set of motor windings. The pulse width modulation signal controls the motor winding drive circuit to cause excitation/unexcitation of the set of motor windings and to alternately changes a direction of current such that the set of motor windings adjusts a speed of the fan motor in response to excitation of the set of motor windings responsive to the pulse width modulation signal. The speed of the fan motor increases when an operational period of the pulse width modulation signal increases, and the speed of the fan motor decreases when the operational period of the pulse width modulation signal decreases.

Abstract: A method for controlling an automatically operated lathe provided with at least one spindle and at least one tool rest includes the following steps. First, each of a plurality of transfer position data required in a sequence of machining programs in connection with at least one spindle and at least one tool rest is provided in a form of either one of two types of transfer position data, one of which is cam-reference data directing a transfer position as a function of a cam rotation quantity and the other is time-reference data directing a transfer position as a function of an elapsed time. Next, a time-series allocation of the cam-reference data and the time-reference data is designated in the sequence of machining programs. Then, the cam-reference data and the time-reference data are processed in accordance with the time-series allocation, so as to control a relative feed motion between at least one spindle and at least one tool rest in the sequence of machining programs.

Abstract: A method for cleaning the bottom of a pool uses an automated programmed pool cleaner capable of reversing movement and turning that is initially placed at an arbitrary location on the bottom of the pool and moved in a forward direction until it encounters an upright pool wall; the unit is reversed until it is a first predetermined distance from the wall, turned through a predetermined angle less than 180° and advanced until it again encounters an upright wall; these steps are repeated until the unit has encountered upright walls a predetermined number of times, after which the first predetermined distance is changed to one or more subsequent predetermined distances. All of the previous steps are repeated until all or substantially all of the pool has been cleaned. In a preferred embodiment, a rectangular pool is cleaned by setting the turning angle to 90° and the number of turns before changing the predetermined distance to seven.

Abstract: A method and apparatus that afford a user accelerated access to operation of a balancing personal transporter. The method includes first initializing a single-axis stabilizer, and, while initializing a 3-axis stabilizer, alerting the rider that the transporter is ready for use, allowing operation of the transporter, and then completing initialization of the 3-axis stabilizer, and employing the 3-axis stabilizer for control of the balancing personal transporter. Apparatus includes single axis and 3-axis stabilizer and means to alert the user of the personal transporter.

Abstract: A controller for a motor is provided. The motor includes N redundant M-phase rotor/stator combinations (where N and M are both integers greater than 1). The controller includes N driver circuits each having M outputs. Each of the M outputs of a respective one of the N driver circuits provides pulse-width modulated (PWM) current pulses to a corresponding phase winding in a respective one of the redundant M-phase rotor/stator combinations. Furthermore, the controller includes a control unit operatively coupled to the N driver circuits for providing phase spacing between the N driver circuits. As a result, current pulses provided by the N driver circuits to a same phase winding in each of the redundant M-phase rotor/stator combinations are offset in phase.

Abstract: A system for controlling a motor comprising: a voltage source including a voltage sensor for detecting a voltage of the voltage source; a motor in operable communication with an inverter, the motor responsive to a command signal from the inverter, the inverter is in operable communication with the voltage source and a controller. The inverter includes a plurality of switching devices configured to receive a command from a controller and generate a voltage command to the motor. The system also includes a controller in operable communication with the inverter and the voltage sensor; the controller configured provide a command to the inverter responsive to the voltage of the voltage source.

Abstract: An apparatus and a method are disclosed for controlling operation of a compressor capable of greatly decreasing a stroke estimation error of a compressor and controlling operation of the compressor accurately and precisely. The method includes calculating a first stroke estimation value of a compressor on the basis of current, a voltage applied to a motor of a compressor and preset parameters of the motor. Detecting a counter electromotive force of the motor and calculating a second stroke estimation value of the compressor on the basis of the detected counter electromotive force value.

Abstract: Methods, devices and circuits for detecting malfunctions in stepper motors. A signal from a driver circuit to a stepper motor that is proportional to the current in the windings of the stepper motor is detected. This signal is then amplified and integrated for ease of comparison. The resulting signal is then compared to a specific entry in a table of values with each entry in the table corresponding to an operating profile of the stepper motor. If the resulting signal does not correspond to the operating profile for which the motor a configured, the stepper motor is jammed. A suitable alarm and a corresponding sequence of actions may then be triggered.

Abstract: A technique for controlling an AC motor. An electric power is output to the AC motor. The output current of an electric power converter is controlled based on a difference signal of an output current detection signal and a current command signal of the electric power converter. When the AC motor is in a free run condition, current control is conducted by forcing the current command signal to be zero so that a current in the AC motor is made zero. The amplitude and phase and angular velocity of a residual voltage of the AC motor are found based on a calculated output voltage command.

Abstract: Systems and methods for controlling and/or calculating the torque for a field oriented induction motor operating at a given stator frequency. The systems and methods include calculating the torque using a first algorithm when the motor is at or below a first predetermined stator frequency, a second algorithm when the motor is at or above a second predetermined stator frequency, and a third algorithm when the motor is between the first predetermined stator frequency and the second predetermined stator frequency.

Abstract: A single phase, three-speed induction motor having 4, 6, and 8-pole speed configurations. In one embodiment, the motor is constructed and arranged to be used in connection with a washing machine. The 8-pole speed winding shares a portion of the 4-pole speed winding, but not all of the 4-pole speed winding is used in the 8-pole configuration. In one embodiment, the 4-pole speed winding includes four winding portions and the 8-pole speed configuration uses two of the four winding portions without the need for additional switch contacts to reconfigure the motor for operating in the 4-pole mode or the 6-pole mode. In one embodiment, shared winding portions are wound on the stator core in a generally non-sinusoidal distribution and non-shared winding portions are wound on the stator core in a generally sinusoidal distribution.

Abstract: An air conditioning apparatus includes a DC power supply, at least one switching mechanism, and a drive circuit. The drive circuit includes an inverter including a plurality of switching elements. The inverter is directly connected to a positive terminal of the DC power supply and is directly connected to a negative terminal of the DC power supply. The drive circuit also includes a DC to DC converter. In one embodiment, a positive terminal of the DC to DC converter is connected to the positive terminal of the DC power supply via the at least one switching mechanism. In another embodiment, a negative terminal of the DC to DC converter is connected to the negative terminal of the DC power supply via the at least one switching mechanism. The drive circuit also includes a switching element circuit coupled to the inverter and to the DC to DC converter. The switching element circuit selectively activates and deactivates the plurality of switching elements.

Abstract: A system and method for battery isolation in a charging system includes an isolation diode connected to a charger input voltage and a PNP pass transistor connected in series between the isolation diode and a battery. The pass device conducts a charging current in response to a drive signal applied to its base; the pass transistor side of the diode is at a voltage Vchg. A first switch couples the pass transistor's base to Vchg when Vchg>Vbat such that the pass transistor's base-collector junction blocks current from Vchg from flowing through the pass transistor when the charger is not in use, and a second switch couples the base to Vbat when Vbat>Vchg such that the pass transistor's base-emitter junction blocks current from the battery from flowing through the pass transistor when the charger is not in use.

Abstract: A protection circuit couples to and protects a battery cell. The protection circuit generally limits the current that can flow through cell when the voltage across the cell falls to a predetermined minimum threshold, such as might occur if the cell is passivated, fails in service, or is reaching the end of its useful life. The protection circuit preferably includes a transistor, which couples in series with the cell and limits the current therethrough. By limiting the current through the cell when its voltage reaches a minimum threshold, the voltage on the cell will not fall below the minimum safe level. A bypass means (e.g., a diode) also is included to conduct current around the cell when its current has been limited by the transistor.

Abstract: A battery charging system includes a first charge source for connection to a first engine and at least a second charge source for connection to at least a second engine. A first battery is connected to the first charge source. At least a second battery is connected to the second charge source. At least a third battery is provided and is connected to a load. A switch is adapted in the first mode of operation to connect the third battery to the first charge source, and in a second mode of operation to connect the third battery to the second charge source. In a third mode of operation, the switch can isolate the third battery from the first and second charge sources as a fail-safe, and provide an alarm of this status. The invention is particularly adapted for use in marine vessels to prevent start batteries from discharging to a point where the voltage is insufficient to start an engine. A switch assembly and a method according to the invention are also disclosed.

Abstract: A method of controlling a generator system connected to an electric power system in which the output frequency characteristic of the generator system is measured, a first phase angle and frequency of the measured frequency characteristic is estimated using a first phase locked loop having a first bandwidth, and a second phase angle and frequency of the measured frequency characteristic is estimated using a second phase locked loop having a second bandwidth greater than the first bandwidth. Further, the method calculates a frequency difference between the first and second estimated frequencies, and an angle variation that is proportional to the calculated frequency difference. The estimated second phase angle is then added to the calculated angle variation so as to form an output current phase angle reference, and an output current phase angle of the generator system is controlled to be aligned with the output current phase angle reference.

Abstract: In an alternator, failure in a power supply line connected to an output terminal of a rectifier is detected. Upon detection of a failure in this power supply line, power generation is suppressed for a predetermined period that is longer than the time constant of a field winding of the alternator. Preferably, a high voltage pulse is detected to discriminate a first condition where a single high voltage pulse is generated when an electrical load connected to the power supply line is cut off and a second condition where a high voltage pulse is repeatedly and frequently generated when a failure occurs in the power supply line. Only when the second condition is discriminated, power generation suppression control of the alternator is conducted.

Abstract: An induction generator power supply comprises a prime mover, an induction generator operably connected to the prime mover and having a generator output, and a phase shift circuit, having a circuit input and a circuit output, the circuit input connected to the generator output. The power supply also comprises an AC to DC converter, having a converter input and a converter output, the converter input connected to the circuit output, and an energy reservoir having a reservoir input connected to the converter output.

Abstract: A power supply in which power conversion efficiency is enhanced in all operation modes by supplying power to a load (60) from any one or both of first power supply circuit (20) and second power supply circuit (40), detecting the operation mode of the load (60) through an operation mode detecting means (65), and controlling switches (11,12) depending on the operation mode of the load (60) to select a power supply circuit for supplying power to the load (60).

Abstract: A diode emulator for a DC—DC buck converter employs a variable current ramp-based circuit that monitors the state of the phase voltage at the common node between two power switching devices. Incrementally with each pulse width modulation cycle, the diode emulator adjusts the time of turn-off of the lower power switching device, until the monitored phase voltage indicates that the emulator is effectively tracking the negative going, zero-crossing of the ripple current through an output inductor.

Abstract: A fast transient response converter is disclosed which makes use of stepping inductor in a switching converter to speed up output voltage response under fast transient condition. The inductive element in a switching converter is replaced by two series or parallel inductive elements, one of which has a smaller value of inductance than the other. During the fast transient period, the inductor with larger inductance value will be shorted to a voltage source. The total inductance will be greatly reduced and thus allows rapid current change during the transient change.

Abstract: A DC-DC conversion type power supply unit has an error amplifier for feeding back the output voltage of the unit to one input terminal of the error amplifier during a startup of the unit. The input terminal is once fixed to a prohibition voltage that prohibits the output of the unit from being outputted therefrom for a predetermined period of time to charge up a feedback condenser. After the period, the feedback condenser discharges its electric charge to gradually raise the voltage of the input terminal to the reference voltage of the power supply unit, thereby allowing a soft start of the power supply unit without changing the reference source voltage of the unit.

Abstract: A switching power supply unit generates a pulse signal having a duty factor based on the voltage associated with the difference between a reference voltage and the output voltage of the unit, and the voltage associated with the current flowing through a smoothing coil. Upon receipt of the pulse signal and a light-load determination signal, a delay-control unit of the power supply unit outputs as an instruction signal supplied to the switching circuit the pulse signal as it is when the light-load determination signal indicates that the load is not light, but otherwise outputs the pulse signal after delaying and widening the pulse width thereof. Thus, when the load is light, the switching power supply unit may hold its switching frequency substantially low and constant without rendering the frequency bursting discontinuously.

Abstract: A reduced power consumption diode circuit has a first voltage comparator that compares a voltage at a cathode terminal with a first sum of a voltage at an anode terminal and a voltage across a second voltage source, and outputs a reset signal. A second voltage comparator compares the voltage at the anode terminal with a second sum of the voltage at the cathode terminal and a voltage across the first voltage source, and outputs a set signal. A first latch circuit outputs a low level signal when the reset signal is input and a high level signal when the set signal is input. A diode has an anode connected to the anode terminal and a cathode connected to the cathode terminal, and an n-channel MOS transistor turns off in response to the low level signal and turns on in response to the high level signal.

Abstract: A bandgap reference circuit includes a current-voltage mirror circuit having first, second, third, and fourth nodes, a transistor having a current path coupled between a source of supply voltage and the first node, a current mirror portion having an input coupled to the first node and a control terminal coupled to the fourth node, a serially coupled first resistor and first diode coupled between the output of the current mirror portion and ground, a serially coupled second resistor and second diode coupled between the third node and ground, a third diode coupled between the second node and ground, and a differential amplifier having a first input coupled to the fourth node, a second input coupled to the output of the current mirror portion for generating a bandgap reference voltage, and an output coupled to the gate of the transistor.

Abstract: An electricity meter performs a self-calibration operation. According to an exemplary embodiment, the meter includes a measurement circuit for generating power information representative of measured power. A controller is operably coupled to the measurement circuit and includes an input for receiving reference standard information. The controller compares the power information generated by the measurement circuit to the reference standard information and generates a compensation signal in dependence upon the comparison. The compensation signal is used to calibrate the measurement circuit. Preferably, the meter is capable of being electrically connected to, and calibrated concurrently with at least one other meter.

Abstract: An electric parts testing system comprises a testing unit to test electric parts for individual condition identifiers assigned for identification of a plurality of test conditions different from each other; a first memory unit which previously stores estimated causes in relation at least to each said condition identifier, said estimated causes being obtained by estimation as causes of defectiveness of the electric parts; a second memory unit to store at least one or more of the condition identifiers regarded as fault-connected identifiers when any of the electric parts are judged to be defective; and an arithmetical unit to calculate a parameter when there are a plurality of said fault-connected identifiers, said parameter being related to the fault-connected identifiers at least for each said estimated cause related to the fault-connected identifiers.

Abstract: A method and apparatus for providing information from a speed and direction sensor is disclosed. The method and apparatus detect the presence of a ferromagnetic object as it moves past a sensor. The sensor determines speed and direction information regarding the ferromagnetic object, and further provides information relating to the environment surrounding the sensor or object, such as the status of an air gap between the sensor and the moving object, and the temperature of the environment in which the sensor or object is disposed.

Abstract: The invention relates to a measuring device for detecting a body moving in relation to an, in particular, tubular container. Said device comprises at least one magnet unit which generates a magnetic field, measures this magnetic field and which is assigned to the container and/or to the magnetic body. The device also comprises at least one evaluation device connected to the magnet units and provided for receiving measurement signals of the magnet units. The aim of the invention is to improve a measuring device of this type in order to be able to easily determine, in addition to the position of the body in relation to the container in a longitudinal direction, the position to the body in relation to the container in the transverse direction with a relatively high level of accuracy. To this end, the magnet units comprise a maximum magnetic flux that is essentially perpendicular to the direction of the relative motion of the body and container.

Abstract: A detector assembly and methods including a magnetoresistive sensor capable of detecting anomalies in the wall of a casing string disposed in a wellbore. Examples of anomalies include gaps between casings such as due to casing joints, air gaps in casing threads such as due to flush casing joints, enlarged casing wall thickness such as due to external casing collars, damaged casing, perforations, and other discontinuities or deformities in the casing. The detector assembly and methods detect perturbations in the earth's magnetic field caused by the anomalies. The detector assembly generates essentially no magnetic or electromagnetic field so that other downhole instrumentation is not affected by its presence.

Abstract: A method and system are presented for measuring in an electrically conductive film of a specific sample including data indicative of a free space response of an RF sensing coil unit to AC voltage applied to the RF sensing coil. The sensing coil is located proximate to the sample at a distance h substantially not exceeding 0.2 r wherein r is the coil radius; an AC voltage in a range from 100 MHz to a few GHz is applied to the sensing coil to cause generation of an eddy current passage through the conductive film; a response of the sensing coil to an effect of the electric current through the conductive film onto a magnetic field of the coil is detected and the measured data indicative of the response is generated. The thickness of the film is determined by utilizing the data indicative of the free space measurements to analyze the measured date. The method thus provides for measuring in conductive films with a sheet resistance Rs in a range from about 0.009 to about 2 Ohm/m2.

Abstract: A method and apparatus for the nondestructive detecting of tension wires in a concrete pole from a single test location without requiring scanning along the length of the pole and without requiring direct contact to the wires. The method and apparatus utilize longitudinal guided waves in tension wires that are generated and detected based on the magnetostrictive sensor principle. The detected signals from broken tension wires and from the ends of concrete pole are analyzed for the number and locations of broken wires.

Abstract: An apparatus can detect a magnetic field with a high sensitivity using an ordinary-temperature pickup coil even when the pickup coil is arranged outside a cryostat. Specifically, the apparatus for measuring a magnetic field includes a pickup coil for detecting an external magnetic field, a SQUID electrically or magnetically connected to the pickup coil, a cryostat for holding the SQUID at low temperatures, and a driving device for driving the SQUID. The pickup coil is made of a normal-conducting material and is placed at an ordinary temperature outside the cryostat. By arranging outside the cryostat, the pickup coil can be brought close to a subject and can thereby detect a weak magnetic field in the subject with a high sensitivity.

Abstract: An NMR instrument for determining formation fluid properties includes a housing adapted to move in a wellbore; a magnet disposed in the housing adapted to induce a static magnetic field; an antenna assembly disposed in the housing adapted to resonate at a first frequency and a second frequency, the first frequency corresponding to a resonance frequency of a first nucleus, the second frequency corresponding to a resonance frequency of a second nucleus, wherein the first nucleus is different from the second nucleus; means for inducing an RF magnetic field; and means for detecting NMR signals at the first frequency. A method of NMR measurement includes inducing a static magnetic field having a selected magnetic field strength in an earth formation sample; acquiring NMR measurements having J coupling information; and deriving the J coupling information from the NMR measurements.

Abstract: A magnetic resonance apparatus has a first microphone that is arranged to pick up acoustic signals emanating from a patient positioned for an examination in the magnetic resonance apparatus, at least one second microphone that is arranged so that it is as free as possible from picking up the acoustic signals, and a processing unit to which the signals of the microphones are fed, and with which noise of the magnetic resonance apparatus, also picked up by both microphones, is eliminated for the purpose of extracting the acoustic signals.

Abstract: A method for eddy current compensated diffusion imaging using magnetic resonance is used to obtain a spin echo signal in a readout time window by excitation of a nuclear resonance signal using a first radio-frequency pulse and by refocusing that signal using at least one second radio-frequency pulse and a third radio-frequency pulse. Gradients fields are applied in a gradient field direction field having a strength and being activated by gradient pulses between each of said radio-frequency pulses and prior to said readout window, said gradient pulses having a polarity which is alternated between successive gradient pulses, with a totality of said gradient pulses having a gradient time integral of zero between a time of said excitation and the center of kx or k-space. At least two of said gradient pulses have differing gradient time integrals. The gradient direction is then changed and the previous steps repeated to evenly distribute gradient direction vectors over a sphere.

Abstract: An underground line locating receiver is disclosed which can determine whether the magnetic field it detects is representative of a line to be located or whether distortions in the magnetic field indicate an anomalous condition, and that therefore the reported line location measurement is suspect.

Abstract: Using micro-resistivity techniques, an image of the wall of a borehole can be obtained. A downhole tool stack is provided with plural imaging tools, wherein each imaging tool has a set of pads that deploy radially outward to contact the borehole wall to obtain the image thereof. As the pads deploy outwardly, gaps are formed between the pads. The pads of one tool are circumferentially offset relative to the pads of the other tool so that more complete circumferential coverage of the borehole wall is obtained during the imaging process. Furthermore, an adaptive polling technique is utilized to telemeter the large amounts of data generated by the two imaging tools to the surface. Data is obtained from the imaging tools by polling at a particular rate, which rate is modified depending upon the amount of data generated by the imaging tools.

Abstract: A circuit breaker test device for testing a circuit breaker, and also for testing the branch circuit of which the circuit breaker is a part. The circuit breaker test device includes a switch that controllably short-circuits the branch circuit. A controller causes the switch to short circuit the branch circuit. A timer, responsive to operation of the controller, causes the switch to cease short-circuiting the branch circuit after a particular test time. An impedance value of the branch circuit is determined. The controller is enabled only if the impedance value is within predetermined limits. The timer is capable of establishing a variable test time.